qid int64 1 74.7M | question stringlengths 12 33.8k | date stringlengths 10 10 | metadata list | response_j stringlengths 0 115k | response_k stringlengths 2 98.3k |
|---|---|---|---|---|---|
2,339 | I upgraded a client system from 4.4.12 to 4.5.8 at the weekend and now message templates are not appearing when a user creates an email (regular or bulk). You can pick a template but nothing appears. In Administer/CiviMail/Message Templates all the templates are there, and can be edited & saved. My other upgrades to 4.5.8 have not shown this problem so I am puzzled - I've cleared the Drupal caches and CiviCRM caches. | 2015/05/14 | [
"https://civicrm.stackexchange.com/questions/2339",
"https://civicrm.stackexchange.com",
"https://civicrm.stackexchange.com/users/254/"
] | This sounds like a javascript problem. You could either [troubleshoot it yourself](http://forum.civicrm.org/index.php/topic,35850.0.html) or just upgrade to the latest version of CiviCRM which has a rewritten CiviMail interface anyway and so the problem is unlikely to be in the new version. | It sounds like a javascript problem. Use your browser development console to to check for a jQuery error on the page due to a theme / block / other module conflict problem. |
2,339 | I upgraded a client system from 4.4.12 to 4.5.8 at the weekend and now message templates are not appearing when a user creates an email (regular or bulk). You can pick a template but nothing appears. In Administer/CiviMail/Message Templates all the templates are there, and can be edited & saved. My other upgrades to 4.5.8 have not shown this problem so I am puzzled - I've cleared the Drupal caches and CiviCRM caches. | 2015/05/14 | [
"https://civicrm.stackexchange.com/questions/2339",
"https://civicrm.stackexchange.com",
"https://civicrm.stackexchange.com/users/254/"
] | This sounds like a javascript problem. You could either [troubleshoot it yourself](http://forum.civicrm.org/index.php/topic,35850.0.html) or just upgrade to the latest version of CiviCRM which has a rewritten CiviMail interface anyway and so the problem is unlikely to be in the new version. | I found an answer for my issue: the Pogstone Module (drupal) was in direct conflict. Removing that module has fixed the issue. |
16,592,456 | I would like to access Sphero while charging with the [node.js SDK](https://github.com/dthompson/node-sphero).
This functionality is included in [Official Android and iOS SDK](http://forum.gosphero.com/archive/index.php/t-967.html) ([SO](https://stackoverflow.com/questions/16366132/sphero-api-access-while-charging-in-cradle)), but not in any of unofficial SDK (based on my knowledge and research).
Is there any way to do it ? It would open a lot a possibility for visual utilization. | 2013/05/16 | [
"https://Stackoverflow.com/questions/16592456",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/277277/"
] | You can use the Sphero bluetooth API to write the appropriate command yourself into the node.js SDK.
The bluetooth API is at: <https://github.com/orbotix/DeveloperResources>
The command you would send is the SetOptionFlags command (35h). You send the id byte of that command, followed by the payload, which is a bitmask. Set the first bit.
I will warn you, though, that this isn't supported behavior. The battery can completely die over a long enough time in the charger. | There is an option flag that can be turned on that will cause Sphero to stay powered on in the charger, you could add it to your SDK like ColdSnickersBar suggests or your could use the Sphero app on iOS or Android.
You can accomplish this in the iOS and Android version of the Sphero app on the Advanced Settings screen. To access the advanced settings quickly tripple tap the Sphero in the middle of the normal settings screen, it can be hard to trigger, it might take several tries. Once you access it turn the "Sleep in Charger" switch to off.
Leaving the ball on in the charger might have a negative impact on your battery life. |
312,697 | I tried asking this question first on StakOverflow in a more concrete manner, but after being pointed here I realized I should rephrase it in more general terms; however, you can still review the [original question](https://stackoverflow.com/questions/35895321/queryover-ensure-adding-a-join-table-only-once), if you want more concrete detail about my specific use case.
Assume a relatively complex reporting interface. For the sake of simplicity, assume we're presenting the resulting data in tabular form only, but we're displaying an aggregate which doesn't map on existing domain objects. The user can select start/end dates from a calendar, can limit their report by specific criteria, and can order the results by specific columns; all of these are optional. Their request is processed by several layers of code, but after processing we end up with a single SQL query that contains filtering conditions, sorting directives, and JOIN statements in order to aggregate data from several tables.
On the database end I'm using an ORM (NHibernate) which handles persistence and coerces me to implement strict entities/domain objects; that's clear and works fine already.
At the other end (towards the user), I have the view which presents stuff to the user, and a controller that interprets in/out data. That's also clear, and it's properly handled.
My question is this: what should happen between those layers? What's the recommended approach towards proper encapsulation? My intuitive approach was to allow my business logic (BL) to call various query helpers that gradually build various parts of the query object, depending on the user's input. That started raising red flags when I ended up having to handle JOINs conditionally in the BL, which is obviously off kilter.
I agree with Frédéric's answer to my [previous question on StackOverflow](https://stackoverflow.com/questions/35895321/queryover-ensure-adding-a-join-table-only-once): move all code that builds the query deeper, closer to the persistence layer, and keep the BL free of any knowledge about the model. That's certainly a cleaner approach, and I could easily define a Data Transfer Object (DTO) to carry the database results "upwards", from the persistence level towards the controller, and ultimately to the view layer. However, the user can fill in a lot of optional input; that means I'll also need an auxiliary class carrying data the other way around, from the controller layer, through the service level where the BL lives, and all the way down to the query helpers themselves on the persistence layer. I don't know what these are called, so let's call them "QTOs", for "Query Transfer Objects" ("query" in the sense of "user queries", not in the sense of SQL). The persistence level would therefore interpret these QTOs into SQL, it would execute the SQL, and it would convert the result set into DTOs that bubble back up.
My problem with this approach is that I'd just be adding a couple of intermediary classes for data transport, but the handling itself would be just the same (only on a different layer). I'd still need to add all of those JOINs conditionally, add criteria conditionally, add sorting directives conditionally – only now I'd have to put in the extra effort of filling in QTOs conditionally in the controller as well! And future refactoring wouldn't be any easier: any changes in the QTO structure would affect both the controller and the model layers – and it's almost guaranteed that any relevant changes to the database structure would result in changes to both the QTOs and the DTOs as well.
In your experience, what is a good way of designing this? Am I over-engineering it? How are my complexity concerns addressed in the design you're using/suggesting? Or are there benefits I'm not seeing that counterbalance the added complexity? | 2016/03/14 | [
"https://softwareengineering.stackexchange.com/questions/312697",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/220411/"
] | You are wise to be wary of over-engineering things. Still, it does sound like your "complex queries" problem context might be a good match for investing in the [interpreter pattern](https://en.wikipedia.org/wiki/Interpreter_pattern), in order to help you abstract (in your BL) the use of your persistence layer, for querying purposes?
Then the question becomes "an interpreter for which query language?" So, I would go back to "stare at" the shape of the various JOINs you would end up writing in your BL with the first approach that you mentioned, and I would try to devise a simple DSL that could be the source query language over your domain for the most frequent/common query patterns.
Alternatively (since you mentioned NHibernate, with a "N") there is also the option of implementing your own [QueryProvider](https://msdn.microsoft.com/library/bb546158(v=vs.110).aspx) if you find Linq's comprehension syntax powerful enough to build those queries. | You need basically a query builder mechanism or a mapper from your UI Layer to the DB.
Since you're using a great ORM already, you will only need to build mapping part, NHibernate will take care of query building.
For the mapping part, you need to get all of the UI specific parameters, and put your query builder logic, finally return results. On any change to the UI you need to run this from scratch.
For the query building part, I recommend you to read this article about NHibernate QueryOver [Query Building Techniques](http://blog.andrewawhitaker.com/blog/2014/08/07/queryover-series-part-6-query-building-techniques/)
**Edit due to comment:**
UI specific code should be on UI layer, data specific code should be on a Repository or DAL layer. But how could these two layers communicate? That is the tricky part.
I often use an additional layer not only for my (DB) entities and interfaces but also models just for communication purposes, that will be common for all my projects (UI, Business, Service etc.). But consider keeping your project only (UI, Business, Service etc.) models in that particular projects.
So, create a common model in entities layer fpr UI to DAL/Repository mapping, fill it in your UI layer (I had called it mapping before), than send to the DAL/Repository layer. With this information you can build the query, execute and send back the results to the UI layer.
I hope this approach helps you. |
166,538 | The Termux app is a terminal emulator. If I create a file or a folder there, and then use another file explorer app to browse my device, where can I find these files? | 2017/01/11 | [
"https://android.stackexchange.com/questions/166538",
"https://android.stackexchange.com",
"https://android.stackexchange.com/users/54300/"
] | You can access the files inside the termux folder by simply doing this. (Without using any third-party app/rooting your device)
Step 1: Go to Downloads on your Device
Step 2: Go to the Appbar
Step 3: Scroll down till you find Termux
Step 4: Click on Termux and you can see your files
 | You can view it easily with Material file manager.
<https://www.learntermux.tech/2020/10/Termux-File-Manager.html>
Here is a guide I found useful to me. |
418,719 | I am told that in Newtonian mechanics, no coordinate system is "superior" to any other. Also, all inertial frames are in a state of constant, rectilinear motion with respect to one another.
So am I right to understand that "inertness of coordinate systems" is an equivalence relation on all the coordinate systems in a space. Furthermore, one should not talk of an inertial coordinate system on its own. In order to talk about inertness one has to choose two coordinate systems and compare them. Finally no equivalence class is superior to another, whatever superior means in its usage in the first paragraph, to which meaning I am not knowledgeable.
If any of this is not true, please include an example as well. | 2013/06/12 | [
"https://math.stackexchange.com/questions/418719",
"https://math.stackexchange.com",
"https://math.stackexchange.com/users/34371/"
] | The statement that no coordinate system is superior to any other would appear to be the source of confusion. I'm not altogether sure what is meant by that statement; it does not reflect how Newtonian mechanics has historically been understood and practiced. Most likely it is intended to reflect a more recent understanding that reflects the development of special and general relativity, but even in the more modern context, I'm not sure what it is trying to say.
The word "inertial" in the term "inertial frame of reference" indicates that the frame is one in which the law of inertia, also known as Newton's first law, holds. That is, it is a frame in which a body not acted on by any forces will remain in the same state of motion, experiencing no acceleration.
One therefore does not speak of one frame being "inertial" with respect to another. Rather, there is a set of preferred frames, the inertial frames, which are all moving with constant rectilinear motion with respect to one another. In all other frames of reference, a body not acted on by any forces *will* undergo accelerations. These can be understood in terms of centrifugal and Coriolis forces, but such forces are considered "fictitious" since they are not caused by interactions with other physical bodies, but instead are due to the choice of coordinate system.
It might seem that Newton's first law is a special case of Newton's second law ($F=ma$) in which the force on a body is zero, but I don't believe that this is how Newton viewed things. Rather, the first law is making a nontrivial statement about the physical world, namely that inertial frames exist. Assuming that forces are due to other bodies and that force falls off with distance, a body sufficiently far from all other bodies could be used as a test body to determine whether a frame is inertial. Once such an inertial frame is found, all frames moving with constant velocity with respect to the first will also be inertial, and all frames that are accelerating with respect to the first will not be inertial. A big question is whether one can find any inertial frames at all: will all test bodies agree on whether a frame is inertial? Newton's first law is asserting that this is so. | This is true for both Newtonian mechanics and special relativity. The transformation between inertial frames is different in the two. One inertial frame can be much more convenient than others for calculation, but that does not make it superior in theory. |
129,198 | I wonder why in single player mode Pokemon trainers (some of them even *exclusively*) use Magikarp that only knows how to perform Splash. [According to this question](https://gaming.stackexchange.com/questions/80566/does-magikarps-splash-move-really-never-deal-any-damage) Splash never even does real damage, unless it's out of PP which takes way too many turns to be a feasible tactic, but who knows maybe that is actually what they're going for? I kind of get that fishermen could employ this tactic, as they probably have a lot of patience fishing their whole life, but why would the real trainers try to… Are they leeching off their opponent's PP this way?
Is there any explanation why a trainer in single player mode would fight somebody with Magikarps that don't know any other moves than Splash? | 2013/08/29 | [
"https://gaming.stackexchange.com/questions/129198",
"https://gaming.stackexchange.com",
"https://gaming.stackexchange.com/users/23901/"
] | remember that in some later Pokemon Games there are Pokefan trainers who focus on either one pokemon (magikarp) or one type of pokemon (water, fish) however i think in all the games there have been Fisherman trainers and there wouldn't bee to many "Fish" pokemon
if the TV series is anything to go by there is also a group who believe in training pokemon but never having them evolve and being just as strong as their fully evolved form (so a Geodude being as strong as a Golem), you could assume that trainer in the game who really shouldn't have any reason to have Magikarp have them could be apart of this group and are trying to train their Magikarp to be as good as Gyarados
one last thing it could be is to make people think of the battle James had in the anime with another trainer where they had both Magikarp or back in the first season when Ash and another trainer fought with 2 Metapods with Harden, the first thing you think off if you face a trainer with all Magicarp | It is just due to the fact that the pokemon trainers use were randomly generated; or it might possibly mean that Game Freak decided to include them because the trainers were trying to evolve their Magikarp to Gyarados. |
129,198 | I wonder why in single player mode Pokemon trainers (some of them even *exclusively*) use Magikarp that only knows how to perform Splash. [According to this question](https://gaming.stackexchange.com/questions/80566/does-magikarps-splash-move-really-never-deal-any-damage) Splash never even does real damage, unless it's out of PP which takes way too many turns to be a feasible tactic, but who knows maybe that is actually what they're going for? I kind of get that fishermen could employ this tactic, as they probably have a lot of patience fishing their whole life, but why would the real trainers try to… Are they leeching off their opponent's PP this way?
Is there any explanation why a trainer in single player mode would fight somebody with Magikarps that don't know any other moves than Splash? | 2013/08/29 | [
"https://gaming.stackexchange.com/questions/129198",
"https://gaming.stackexchange.com",
"https://gaming.stackexchange.com/users/23901/"
] | Consider this, at that point in the game, you should have at least passed the first gym leader, more or less, and are on your way to the next gym leader. Not true for all cases, but at that point in the game, you should be familiar with all the game mechanics.
That said, consider it as experience fodder. It's an equivalent of finding a [Audino](http://bulbapedia.bulbagarden.net/wiki/Audino_%28Pok%C3%A9mon%29)
out in the wild; it's just a nice boost of free experience, not only for your lead Pokemon, but for other Pokemon you'd like to get a nice boost of exp with. 6 Magikarps, all using Splash can be a nice way for you to get your Pokemon to the next level, next evolution, etc., kind of like "breathing room".
From my experience, the Magikarp trainers would always be outside one of the "forests" you encounter along the game, the ones that have tons of grass, tons of trainers, and no heals for your team (with the usual Nurse here and there(after a battle). You can also then think of this battle of a "joke", because after all your trainer's been through, facing off against a team of Magikarp's? PFFFFFFFF
That's the only explanation I believe would best fit the reason the trainer using Magikarp (besides the hypothetical inside joke). | It is just due to the fact that the pokemon trainers use were randomly generated; or it might possibly mean that Game Freak decided to include them because the trainers were trying to evolve their Magikarp to Gyarados. |
129,198 | I wonder why in single player mode Pokemon trainers (some of them even *exclusively*) use Magikarp that only knows how to perform Splash. [According to this question](https://gaming.stackexchange.com/questions/80566/does-magikarps-splash-move-really-never-deal-any-damage) Splash never even does real damage, unless it's out of PP which takes way too many turns to be a feasible tactic, but who knows maybe that is actually what they're going for? I kind of get that fishermen could employ this tactic, as they probably have a lot of patience fishing their whole life, but why would the real trainers try to… Are they leeching off their opponent's PP this way?
Is there any explanation why a trainer in single player mode would fight somebody with Magikarps that don't know any other moves than Splash? | 2013/08/29 | [
"https://gaming.stackexchange.com/questions/129198",
"https://gaming.stackexchange.com",
"https://gaming.stackexchange.com/users/23901/"
] | Consider this, at that point in the game, you should have at least passed the first gym leader, more or less, and are on your way to the next gym leader. Not true for all cases, but at that point in the game, you should be familiar with all the game mechanics.
That said, consider it as experience fodder. It's an equivalent of finding a [Audino](http://bulbapedia.bulbagarden.net/wiki/Audino_%28Pok%C3%A9mon%29)
out in the wild; it's just a nice boost of free experience, not only for your lead Pokemon, but for other Pokemon you'd like to get a nice boost of exp with. 6 Magikarps, all using Splash can be a nice way for you to get your Pokemon to the next level, next evolution, etc., kind of like "breathing room".
From my experience, the Magikarp trainers would always be outside one of the "forests" you encounter along the game, the ones that have tons of grass, tons of trainers, and no heals for your team (with the usual Nurse here and there(after a battle). You can also then think of this battle of a "joke", because after all your trainer's been through, facing off against a team of Magikarp's? PFFFFFFFF
That's the only explanation I believe would best fit the reason the trainer using Magikarp (besides the hypothetical inside joke). | remember that in some later Pokemon Games there are Pokefan trainers who focus on either one pokemon (magikarp) or one type of pokemon (water, fish) however i think in all the games there have been Fisherman trainers and there wouldn't bee to many "Fish" pokemon
if the TV series is anything to go by there is also a group who believe in training pokemon but never having them evolve and being just as strong as their fully evolved form (so a Geodude being as strong as a Golem), you could assume that trainer in the game who really shouldn't have any reason to have Magikarp have them could be apart of this group and are trying to train their Magikarp to be as good as Gyarados
one last thing it could be is to make people think of the battle James had in the anime with another trainer where they had both Magikarp or back in the first season when Ash and another trainer fought with 2 Metapods with Harden, the first thing you think off if you face a trainer with all Magicarp |
143,948 | Our company runs about 1,000 websites for various clients, and we just implemented a feature that will allow them to create their own modals in a "back end" that we've created for them. They are basic [Bootstrap Modals](https://getbootstrap.com/docs/5.0/components/modal/) and the feature works great.
We're at the point of "selling" the product to our clients, but management fears the term "Modal" isn't in the client's lexicon, so we're trying to figure out a better term. Web standards over the years have labeled "pop up" with such stigma we won't go anywhere near that .. And while technically a popup is a separated browser window opened without the consent of the surfer, the stigma around the word is still there.
What do you webmasters call Modals when talking to your non-tech-savvy clients? Do we just try to call them Modals and have a "what's this" icon? IMHO Management is heaving around geriatric terms like "online billboard", which is an outdated concept, on top of using a "sales" term -- Which these are more for notifications, even if advertising a discount. I like something more like "A place for important notifications" but that's wordy .. Is there an industry standard laymen's word for the term "modal"? | 2022/07/19 | [
"https://ux.stackexchange.com/questions/143948",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/158765/"
] | Perhaps you should go to the historical origin of the *modal* word applied to UI to find more generic alternatives. Sometimes the terms used in the definition are more elementary than those defined.
There is an interesting answer on [EnglishSE](https://english.stackexchange.com/questions/103192/etymology-of-modal-dialogs-in-computerese) where you can get ideas:
>
> Modal:
> Restrictive or limited interaction due to operating in a mode. Modal often describes a **secondary window** that restricts a user's interaction with the owner window.
>
>
>
>
> With a modal dialog, you set your application in a particular mode (a different "state" if you will), whereby only actions pertaining to that "mode" are accepted, hence preventing UI actions outside of the **dialog**.
>
>
>
But, if I had to explain the operation of a modal window to a child or an elderly person not used to working with computers, the first thing that comes to mind as symbols is the comic bubbles: **Info bubble**. From which more intuitive ideas can arise such as: **Descriptive bubbles**, **Informative bubbles** where *bubble* can be replaced by **dialog**, **box**, **frame**, **panel**.
In [Adobe applications](https://helpx.adobe.com/fireworks/kb/show-dont-show-dialog.html) there are modals with *specific advice or tips* that can be displayed only once and then permanently hidden by the user. Adobe simply calls them **dialogs**. | The proper name is **["Modal Window"](https://en.wikipedia.org/wiki/Modal_window)**, but you can also present it as a modal dialog box, pop-up window, pop-up notification, or even lightbox.
Regardless of what you call it, it's a good idea to explain what it is and what kind of content your users can view in these modal windows by using an an image or even an animation of the interaction. |
143,948 | Our company runs about 1,000 websites for various clients, and we just implemented a feature that will allow them to create their own modals in a "back end" that we've created for them. They are basic [Bootstrap Modals](https://getbootstrap.com/docs/5.0/components/modal/) and the feature works great.
We're at the point of "selling" the product to our clients, but management fears the term "Modal" isn't in the client's lexicon, so we're trying to figure out a better term. Web standards over the years have labeled "pop up" with such stigma we won't go anywhere near that .. And while technically a popup is a separated browser window opened without the consent of the surfer, the stigma around the word is still there.
What do you webmasters call Modals when talking to your non-tech-savvy clients? Do we just try to call them Modals and have a "what's this" icon? IMHO Management is heaving around geriatric terms like "online billboard", which is an outdated concept, on top of using a "sales" term -- Which these are more for notifications, even if advertising a discount. I like something more like "A place for important notifications" but that's wordy .. Is there an industry standard laymen's word for the term "modal"? | 2022/07/19 | [
"https://ux.stackexchange.com/questions/143948",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/158765/"
] | "Modal" describes how it works (preventing any other operations being performed while the child window is open), not what it looks like (which is typically what clients use to communicate).
In the context of the web, I'd probably use the word "overlay" if it's a generic modal that can be used for any purpose. If it's for confirmation prompts, etc., dialog boxes, alerts and prompts are all words that get used to describe this kind of thing pretty commonly.
For image galleries, they're often called "lightboxes". | The proper name is **["Modal Window"](https://en.wikipedia.org/wiki/Modal_window)**, but you can also present it as a modal dialog box, pop-up window, pop-up notification, or even lightbox.
Regardless of what you call it, it's a good idea to explain what it is and what kind of content your users can view in these modal windows by using an an image or even an animation of the interaction. |
143,948 | Our company runs about 1,000 websites for various clients, and we just implemented a feature that will allow them to create their own modals in a "back end" that we've created for them. They are basic [Bootstrap Modals](https://getbootstrap.com/docs/5.0/components/modal/) and the feature works great.
We're at the point of "selling" the product to our clients, but management fears the term "Modal" isn't in the client's lexicon, so we're trying to figure out a better term. Web standards over the years have labeled "pop up" with such stigma we won't go anywhere near that .. And while technically a popup is a separated browser window opened without the consent of the surfer, the stigma around the word is still there.
What do you webmasters call Modals when talking to your non-tech-savvy clients? Do we just try to call them Modals and have a "what's this" icon? IMHO Management is heaving around geriatric terms like "online billboard", which is an outdated concept, on top of using a "sales" term -- Which these are more for notifications, even if advertising a discount. I like something more like "A place for important notifications" but that's wordy .. Is there an industry standard laymen's word for the term "modal"? | 2022/07/19 | [
"https://ux.stackexchange.com/questions/143948",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/158765/"
] | The proper name is **["Modal Window"](https://en.wikipedia.org/wiki/Modal_window)**, but you can also present it as a modal dialog box, pop-up window, pop-up notification, or even lightbox.
Regardless of what you call it, it's a good idea to explain what it is and what kind of content your users can view in these modal windows by using an an image or even an animation of the interaction. | When it comes to nomenclature in the IT sector, there usually seems to be a mixture of terms that stems from the technical and programming language that sometimes evolve over time in a more design-centric environment that reflects the use of languages and terms that are closer to what a non-technical person might use.
A [clear description of what a modal is](https://blog.hubspot.com/website/modal-web-design) and the traditional/conventional behaviour of modals is the implementation of another mode of viewing content for the user. In the past this involved introducing a window and a background that obscures or hides the previous window or content. Hence it was also called a lightbox because only the current context or content is lighted up and everything else goes to the background.
These days, there are variations on how you can implement this behaviour, and therefore I think more generic terms have been defined. A very common term used is [popup](https://www.w3schools.com/howto/howto_js_popup.asp), which is essentially anything that 'pops up' on the screen when something triggers it to do so (like those annoying sign up dialog boxes). But that's only one part of the description, which defines the behaviour but not the look of the component.
There are [a myriad of examples](https://reactjsexample.com/tag/popup/) (and terms) ranging from dialog, window, notifications, toast, alert that describe various visual and styling elements which are often associated with a popup type of behaviour.
Depending on how specific you want to be, you can propose something like a "pop-up window" or "dialog box" to a client that can mean basically anything that can be triggered to display some content and invite some interaction to something very specific like a "sign-up form" or "pop-up feedback survey" to describe specific use cases. |
143,948 | Our company runs about 1,000 websites for various clients, and we just implemented a feature that will allow them to create their own modals in a "back end" that we've created for them. They are basic [Bootstrap Modals](https://getbootstrap.com/docs/5.0/components/modal/) and the feature works great.
We're at the point of "selling" the product to our clients, but management fears the term "Modal" isn't in the client's lexicon, so we're trying to figure out a better term. Web standards over the years have labeled "pop up" with such stigma we won't go anywhere near that .. And while technically a popup is a separated browser window opened without the consent of the surfer, the stigma around the word is still there.
What do you webmasters call Modals when talking to your non-tech-savvy clients? Do we just try to call them Modals and have a "what's this" icon? IMHO Management is heaving around geriatric terms like "online billboard", which is an outdated concept, on top of using a "sales" term -- Which these are more for notifications, even if advertising a discount. I like something more like "A place for important notifications" but that's wordy .. Is there an industry standard laymen's word for the term "modal"? | 2022/07/19 | [
"https://ux.stackexchange.com/questions/143948",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/158765/"
] | "Modal" describes how it works (preventing any other operations being performed while the child window is open), not what it looks like (which is typically what clients use to communicate).
In the context of the web, I'd probably use the word "overlay" if it's a generic modal that can be used for any purpose. If it's for confirmation prompts, etc., dialog boxes, alerts and prompts are all words that get used to describe this kind of thing pretty commonly.
For image galleries, they're often called "lightboxes". | Perhaps you should go to the historical origin of the *modal* word applied to UI to find more generic alternatives. Sometimes the terms used in the definition are more elementary than those defined.
There is an interesting answer on [EnglishSE](https://english.stackexchange.com/questions/103192/etymology-of-modal-dialogs-in-computerese) where you can get ideas:
>
> Modal:
> Restrictive or limited interaction due to operating in a mode. Modal often describes a **secondary window** that restricts a user's interaction with the owner window.
>
>
>
>
> With a modal dialog, you set your application in a particular mode (a different "state" if you will), whereby only actions pertaining to that "mode" are accepted, hence preventing UI actions outside of the **dialog**.
>
>
>
But, if I had to explain the operation of a modal window to a child or an elderly person not used to working with computers, the first thing that comes to mind as symbols is the comic bubbles: **Info bubble**. From which more intuitive ideas can arise such as: **Descriptive bubbles**, **Informative bubbles** where *bubble* can be replaced by **dialog**, **box**, **frame**, **panel**.
In [Adobe applications](https://helpx.adobe.com/fireworks/kb/show-dont-show-dialog.html) there are modals with *specific advice or tips* that can be displayed only once and then permanently hidden by the user. Adobe simply calls them **dialogs**. |
143,948 | Our company runs about 1,000 websites for various clients, and we just implemented a feature that will allow them to create their own modals in a "back end" that we've created for them. They are basic [Bootstrap Modals](https://getbootstrap.com/docs/5.0/components/modal/) and the feature works great.
We're at the point of "selling" the product to our clients, but management fears the term "Modal" isn't in the client's lexicon, so we're trying to figure out a better term. Web standards over the years have labeled "pop up" with such stigma we won't go anywhere near that .. And while technically a popup is a separated browser window opened without the consent of the surfer, the stigma around the word is still there.
What do you webmasters call Modals when talking to your non-tech-savvy clients? Do we just try to call them Modals and have a "what's this" icon? IMHO Management is heaving around geriatric terms like "online billboard", which is an outdated concept, on top of using a "sales" term -- Which these are more for notifications, even if advertising a discount. I like something more like "A place for important notifications" but that's wordy .. Is there an industry standard laymen's word for the term "modal"? | 2022/07/19 | [
"https://ux.stackexchange.com/questions/143948",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/158765/"
] | Perhaps you should go to the historical origin of the *modal* word applied to UI to find more generic alternatives. Sometimes the terms used in the definition are more elementary than those defined.
There is an interesting answer on [EnglishSE](https://english.stackexchange.com/questions/103192/etymology-of-modal-dialogs-in-computerese) where you can get ideas:
>
> Modal:
> Restrictive or limited interaction due to operating in a mode. Modal often describes a **secondary window** that restricts a user's interaction with the owner window.
>
>
>
>
> With a modal dialog, you set your application in a particular mode (a different "state" if you will), whereby only actions pertaining to that "mode" are accepted, hence preventing UI actions outside of the **dialog**.
>
>
>
But, if I had to explain the operation of a modal window to a child or an elderly person not used to working with computers, the first thing that comes to mind as symbols is the comic bubbles: **Info bubble**. From which more intuitive ideas can arise such as: **Descriptive bubbles**, **Informative bubbles** where *bubble* can be replaced by **dialog**, **box**, **frame**, **panel**.
In [Adobe applications](https://helpx.adobe.com/fireworks/kb/show-dont-show-dialog.html) there are modals with *specific advice or tips* that can be displayed only once and then permanently hidden by the user. Adobe simply calls them **dialogs**. | In a comment to the question, you indicate your clients are expected to use these Modals for must-see messages, so "Important Message" and "Critical Notification" seem to be good labels for the feature. These are plain English (adjective-noun), and describe *what* the feature does instead of *how* it is done, which should aid comprehension and adoption.
Further, if your clients like the feature, you will have carved out space for a future more general feature "Notifications" with numerous attributes to control timing and behavior, and which could be triggered from an event handler, used as an operation flow step, marked as critical which would force them to be acknowledged/dismissed, etc. |
143,948 | Our company runs about 1,000 websites for various clients, and we just implemented a feature that will allow them to create their own modals in a "back end" that we've created for them. They are basic [Bootstrap Modals](https://getbootstrap.com/docs/5.0/components/modal/) and the feature works great.
We're at the point of "selling" the product to our clients, but management fears the term "Modal" isn't in the client's lexicon, so we're trying to figure out a better term. Web standards over the years have labeled "pop up" with such stigma we won't go anywhere near that .. And while technically a popup is a separated browser window opened without the consent of the surfer, the stigma around the word is still there.
What do you webmasters call Modals when talking to your non-tech-savvy clients? Do we just try to call them Modals and have a "what's this" icon? IMHO Management is heaving around geriatric terms like "online billboard", which is an outdated concept, on top of using a "sales" term -- Which these are more for notifications, even if advertising a discount. I like something more like "A place for important notifications" but that's wordy .. Is there an industry standard laymen's word for the term "modal"? | 2022/07/19 | [
"https://ux.stackexchange.com/questions/143948",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/158765/"
] | Perhaps you should go to the historical origin of the *modal* word applied to UI to find more generic alternatives. Sometimes the terms used in the definition are more elementary than those defined.
There is an interesting answer on [EnglishSE](https://english.stackexchange.com/questions/103192/etymology-of-modal-dialogs-in-computerese) where you can get ideas:
>
> Modal:
> Restrictive or limited interaction due to operating in a mode. Modal often describes a **secondary window** that restricts a user's interaction with the owner window.
>
>
>
>
> With a modal dialog, you set your application in a particular mode (a different "state" if you will), whereby only actions pertaining to that "mode" are accepted, hence preventing UI actions outside of the **dialog**.
>
>
>
But, if I had to explain the operation of a modal window to a child or an elderly person not used to working with computers, the first thing that comes to mind as symbols is the comic bubbles: **Info bubble**. From which more intuitive ideas can arise such as: **Descriptive bubbles**, **Informative bubbles** where *bubble* can be replaced by **dialog**, **box**, **frame**, **panel**.
In [Adobe applications](https://helpx.adobe.com/fireworks/kb/show-dont-show-dialog.html) there are modals with *specific advice or tips* that can be displayed only once and then permanently hidden by the user. Adobe simply calls them **dialogs**. | When it comes to nomenclature in the IT sector, there usually seems to be a mixture of terms that stems from the technical and programming language that sometimes evolve over time in a more design-centric environment that reflects the use of languages and terms that are closer to what a non-technical person might use.
A [clear description of what a modal is](https://blog.hubspot.com/website/modal-web-design) and the traditional/conventional behaviour of modals is the implementation of another mode of viewing content for the user. In the past this involved introducing a window and a background that obscures or hides the previous window or content. Hence it was also called a lightbox because only the current context or content is lighted up and everything else goes to the background.
These days, there are variations on how you can implement this behaviour, and therefore I think more generic terms have been defined. A very common term used is [popup](https://www.w3schools.com/howto/howto_js_popup.asp), which is essentially anything that 'pops up' on the screen when something triggers it to do so (like those annoying sign up dialog boxes). But that's only one part of the description, which defines the behaviour but not the look of the component.
There are [a myriad of examples](https://reactjsexample.com/tag/popup/) (and terms) ranging from dialog, window, notifications, toast, alert that describe various visual and styling elements which are often associated with a popup type of behaviour.
Depending on how specific you want to be, you can propose something like a "pop-up window" or "dialog box" to a client that can mean basically anything that can be triggered to display some content and invite some interaction to something very specific like a "sign-up form" or "pop-up feedback survey" to describe specific use cases. |
143,948 | Our company runs about 1,000 websites for various clients, and we just implemented a feature that will allow them to create their own modals in a "back end" that we've created for them. They are basic [Bootstrap Modals](https://getbootstrap.com/docs/5.0/components/modal/) and the feature works great.
We're at the point of "selling" the product to our clients, but management fears the term "Modal" isn't in the client's lexicon, so we're trying to figure out a better term. Web standards over the years have labeled "pop up" with such stigma we won't go anywhere near that .. And while technically a popup is a separated browser window opened without the consent of the surfer, the stigma around the word is still there.
What do you webmasters call Modals when talking to your non-tech-savvy clients? Do we just try to call them Modals and have a "what's this" icon? IMHO Management is heaving around geriatric terms like "online billboard", which is an outdated concept, on top of using a "sales" term -- Which these are more for notifications, even if advertising a discount. I like something more like "A place for important notifications" but that's wordy .. Is there an industry standard laymen's word for the term "modal"? | 2022/07/19 | [
"https://ux.stackexchange.com/questions/143948",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/158765/"
] | "Modal" describes how it works (preventing any other operations being performed while the child window is open), not what it looks like (which is typically what clients use to communicate).
In the context of the web, I'd probably use the word "overlay" if it's a generic modal that can be used for any purpose. If it's for confirmation prompts, etc., dialog boxes, alerts and prompts are all words that get used to describe this kind of thing pretty commonly.
For image galleries, they're often called "lightboxes". | In a comment to the question, you indicate your clients are expected to use these Modals for must-see messages, so "Important Message" and "Critical Notification" seem to be good labels for the feature. These are plain English (adjective-noun), and describe *what* the feature does instead of *how* it is done, which should aid comprehension and adoption.
Further, if your clients like the feature, you will have carved out space for a future more general feature "Notifications" with numerous attributes to control timing and behavior, and which could be triggered from an event handler, used as an operation flow step, marked as critical which would force them to be acknowledged/dismissed, etc. |
143,948 | Our company runs about 1,000 websites for various clients, and we just implemented a feature that will allow them to create their own modals in a "back end" that we've created for them. They are basic [Bootstrap Modals](https://getbootstrap.com/docs/5.0/components/modal/) and the feature works great.
We're at the point of "selling" the product to our clients, but management fears the term "Modal" isn't in the client's lexicon, so we're trying to figure out a better term. Web standards over the years have labeled "pop up" with such stigma we won't go anywhere near that .. And while technically a popup is a separated browser window opened without the consent of the surfer, the stigma around the word is still there.
What do you webmasters call Modals when talking to your non-tech-savvy clients? Do we just try to call them Modals and have a "what's this" icon? IMHO Management is heaving around geriatric terms like "online billboard", which is an outdated concept, on top of using a "sales" term -- Which these are more for notifications, even if advertising a discount. I like something more like "A place for important notifications" but that's wordy .. Is there an industry standard laymen's word for the term "modal"? | 2022/07/19 | [
"https://ux.stackexchange.com/questions/143948",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/158765/"
] | "Modal" describes how it works (preventing any other operations being performed while the child window is open), not what it looks like (which is typically what clients use to communicate).
In the context of the web, I'd probably use the word "overlay" if it's a generic modal that can be used for any purpose. If it's for confirmation prompts, etc., dialog boxes, alerts and prompts are all words that get used to describe this kind of thing pretty commonly.
For image galleries, they're often called "lightboxes". | When it comes to nomenclature in the IT sector, there usually seems to be a mixture of terms that stems from the technical and programming language that sometimes evolve over time in a more design-centric environment that reflects the use of languages and terms that are closer to what a non-technical person might use.
A [clear description of what a modal is](https://blog.hubspot.com/website/modal-web-design) and the traditional/conventional behaviour of modals is the implementation of another mode of viewing content for the user. In the past this involved introducing a window and a background that obscures or hides the previous window or content. Hence it was also called a lightbox because only the current context or content is lighted up and everything else goes to the background.
These days, there are variations on how you can implement this behaviour, and therefore I think more generic terms have been defined. A very common term used is [popup](https://www.w3schools.com/howto/howto_js_popup.asp), which is essentially anything that 'pops up' on the screen when something triggers it to do so (like those annoying sign up dialog boxes). But that's only one part of the description, which defines the behaviour but not the look of the component.
There are [a myriad of examples](https://reactjsexample.com/tag/popup/) (and terms) ranging from dialog, window, notifications, toast, alert that describe various visual and styling elements which are often associated with a popup type of behaviour.
Depending on how specific you want to be, you can propose something like a "pop-up window" or "dialog box" to a client that can mean basically anything that can be triggered to display some content and invite some interaction to something very specific like a "sign-up form" or "pop-up feedback survey" to describe specific use cases. |
143,948 | Our company runs about 1,000 websites for various clients, and we just implemented a feature that will allow them to create their own modals in a "back end" that we've created for them. They are basic [Bootstrap Modals](https://getbootstrap.com/docs/5.0/components/modal/) and the feature works great.
We're at the point of "selling" the product to our clients, but management fears the term "Modal" isn't in the client's lexicon, so we're trying to figure out a better term. Web standards over the years have labeled "pop up" with such stigma we won't go anywhere near that .. And while technically a popup is a separated browser window opened without the consent of the surfer, the stigma around the word is still there.
What do you webmasters call Modals when talking to your non-tech-savvy clients? Do we just try to call them Modals and have a "what's this" icon? IMHO Management is heaving around geriatric terms like "online billboard", which is an outdated concept, on top of using a "sales" term -- Which these are more for notifications, even if advertising a discount. I like something more like "A place for important notifications" but that's wordy .. Is there an industry standard laymen's word for the term "modal"? | 2022/07/19 | [
"https://ux.stackexchange.com/questions/143948",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/158765/"
] | In a comment to the question, you indicate your clients are expected to use these Modals for must-see messages, so "Important Message" and "Critical Notification" seem to be good labels for the feature. These are plain English (adjective-noun), and describe *what* the feature does instead of *how* it is done, which should aid comprehension and adoption.
Further, if your clients like the feature, you will have carved out space for a future more general feature "Notifications" with numerous attributes to control timing and behavior, and which could be triggered from an event handler, used as an operation flow step, marked as critical which would force them to be acknowledged/dismissed, etc. | When it comes to nomenclature in the IT sector, there usually seems to be a mixture of terms that stems from the technical and programming language that sometimes evolve over time in a more design-centric environment that reflects the use of languages and terms that are closer to what a non-technical person might use.
A [clear description of what a modal is](https://blog.hubspot.com/website/modal-web-design) and the traditional/conventional behaviour of modals is the implementation of another mode of viewing content for the user. In the past this involved introducing a window and a background that obscures or hides the previous window or content. Hence it was also called a lightbox because only the current context or content is lighted up and everything else goes to the background.
These days, there are variations on how you can implement this behaviour, and therefore I think more generic terms have been defined. A very common term used is [popup](https://www.w3schools.com/howto/howto_js_popup.asp), which is essentially anything that 'pops up' on the screen when something triggers it to do so (like those annoying sign up dialog boxes). But that's only one part of the description, which defines the behaviour but not the look of the component.
There are [a myriad of examples](https://reactjsexample.com/tag/popup/) (and terms) ranging from dialog, window, notifications, toast, alert that describe various visual and styling elements which are often associated with a popup type of behaviour.
Depending on how specific you want to be, you can propose something like a "pop-up window" or "dialog box" to a client that can mean basically anything that can be triggered to display some content and invite some interaction to something very specific like a "sign-up form" or "pop-up feedback survey" to describe specific use cases. |
122,687 | I have a Debian machine (actually a Raspberry Pi) that I would like to use as a rudimentary, outgoing-only mail server over a residential connection, just for kicks. Port 25 is blocked. I would like to set it up as a standalone SMTP server, not a relay. Is that possible?
Comcast gives the impression I can use port 587 instead. <http://customer.comcast.com/help-and-support/internet/email-port-25-no-longer-supported/>
So does this guy (and a few others): <http://dragos.fedorovici.com/exim-alternate-port-587/>
But this answer <https://serverfault.com/questions/452653/many-isps-is-block-port-25-how-do-i-choose-an-alternative-port/> sounds like 587 is only for use within local networks.
Nothing I have tried works. It would be nice to know if the task is possible.
**EDIT:** I didn't explicitly mention this, but I would like typical mail servers to be able to receive mail that I send from my machine. | 2014/04/02 | [
"https://unix.stackexchange.com/questions/122687",
"https://unix.stackexchange.com",
"https://unix.stackexchange.com/users/64171/"
] | If your ISP is blocking traffic that you send destined for another host's TCP port 25, you will not be able to set up an outbound mail server.
Conversely, if they are blocking inbound connections to your TCP port 25, other mail servers would not be able to deliver messages to you.
Additionally, it is typically not very effective sending mail directly from dynamic IP space because commonly these netblocks are abused by malware and viruses to send spam and, as a consequence, many mail servers ignore them outright.
Port 25 is the only port used between MTAs for delivery. Other ports you might read about are only used by MUAs (clients) for relay purposes.
You could configure your local MTA to use your ISP's mail relay as a smart host (outbound). | Port 25 is now generally considered "legacy SMTP". All my new SMTP boxes have used port 587 for some time now. There is nothing non-standard about it, in fact it is considered the norm today.
See Wikipedia's [list of ports](http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers). |
30,674 | Im looking into making the switch from platforms to clip-less and just saw SPD pedals with "Click'R" technology ( [Example](http://rads.stackoverflow.com/amzn/click/B00D85K5OA) ) Im not sure if its worth the extra money to buy that opposed to SPD pedals without the "Click'r" Technology.
**Has anyone tried both?**
**What do you think?**
This will also be my first ever pair of clip-less pedals so i prefer something beginner friendly which is what the "click'r" advertises
Just found this from the Shimano Website a great video Describing their Click'R Technology [Youtube](http://rads.stackoverflow.com/amzn/click/B00D85K5OA)
Their Website also has a great Diagram
<http://www.shimano-lifestylegear.com/us/fw/technologies/clickr.php> | 2015/05/19 | [
"https://bicycles.stackexchange.com/questions/30674",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/19573/"
] | Another option to that new system is the existing SPD system with the ["Multi-Directional" cleat (SM-SH56)](http://www.shimano-lifestylegear.com/us/fw/products/accessory/cleat.php?pSccleat002). This cleat just makes the step-in and release a little easier than the standard cleat (no numbers on it).
The advantage (over the Click'R) is that it's using the tried-and-true SPD system, and when you get comfortable with that cleat, you can replace it with the standard cleat for a more secure connection.
The cleat may not be as recessed as the Click'R, but with standard MTB shoes there's usually enough shoe tread around the cleat to provide normal walking (I've never had a problem slipping on my cleat). | The Click'R system allows for a more recessed cleat in the shoe. It is a very similar design to Shimano SPD but is marketed for commuters and trekkers who want dual purpose shoes for when they are on and off the bike.
They also allow for multi-release meaning they offer a wider range of movement to release the cleat from the pedal making them easier to use. |
341,355 | I come across a set of questions like these:
[What are the differences between Network and HTTP(s) load balancer in GCP](https://stackoverflow.com/questions/41535226/difference-between-network-and-https-load-balancer-in-gcp/41535227)
[How do I configure managed instance group and autoscaling in Google Cloud Platform](https://stackoverflow.com/questions/41541761/setting-up-managed-instance-group-and-autoscaling-in-google-cloud-platform/41541762#41541762)
which are actually part of an attempt to answer part of the original question here: [Use existent VM Instace (bitnami) for Autoscale Group of Instances](https://stackoverflow.com/questions/41467192/use-existent-vm-instace-bitnami-for-autoscale-group-of-instances/41541921#41541921)
It seems to me this approach helps the OP to break down the original question into smaller parts and make it easier to answer and respond.
On the downside I can see it can lead to a lot of small Q&A that might be devoid of context.
Do you think it is a good idea? | 2017/01/11 | [
"https://meta.stackoverflow.com/questions/341355",
"https://meta.stackoverflow.com",
"https://meta.stackoverflow.com/users/58129/"
] | >
> Is it a good practice? Create smaller questions to answer an original question by another user
>
>
>
Of course it's a good practice: you are breaking down a "too broad" question, with it's subsets that can arguably reused on other purposes. Do note, each of these questions should be able to stand on their own: they are within the bounds of what SO considers a good question.
>
> It seems to me this approach helps the OP to break down the original question into smaller parts and make it easier to answer and respond.
>
>
>
Good for him! He's using the site how it meant to be used: asking specific questions that allow competing answers. So, rather than "How do I go about designing an exact bow and arrow with the dart board and quiver like the one below using CSS only?", he asks "How to give the sensation of profundity to a circumference?", "How can I make complex shape, like a bow?", "How to allow a element to be dragged?", etc. As Tim post said:
>
> there seems to be quite a bit of useful stuff there, *it's just unfortunately compiled in a way that doesn't work well for Stack Overflow*.
>
>
>
So, make sure that the content you submit is compiled in a way that works with SO. | The idea of breaking down a broad question into sub-questions seems like a good one - it's basically what the "too broad" policy is *instructing* you to do. But these new questions should be *instead of* the original, not subservient to it. And the fact they were created this way is a historical footnote, not an on-going part of their existence.
If the original question is too broad, it may at some point be closed, and even deleted. It's therefore imperative that the new questions don't rely on it, and probably they shouldn't even reference it. They might reference *each other*, or maybe the answer to one might reference another, but if you end up writing "this is part 1 of a series of 10, click here to see the index", you're no longer writing a Q&A, you're writing a blog or tutorial. And that doesn't belong here.
What's more, each of these new questions will stand and fall on its own merits; they should each be high quality and on-topic. If you split a question into a part that discusses software design, and a part that covers hardware configuration, the hardware part will probably be flagged as "Off-topic, migrate to Super User or Server Fault?" So even linking between the questions should be incidental, not essential to understanding each. |
9,636 | As the center of gravity between Pluto and Charon is outside Pluto does Pluto's satellites other than Charon such as Nix, Hydra, Kerberos or Styx orbits around Pluto or the COG? | 2015/06/24 | [
"https://space.stackexchange.com/questions/9636",
"https://space.stackexchange.com",
"https://space.stackexchange.com/users/10579/"
] | The other moons orbit around both Pluto and Charon, so in a way it is accurate to say that they orbit the Pluto-Charon system rather than just Pluto, since Pluto and Charon orbit a center of gravity outside of Pluto. For now, the IAU has not pursued classifying Pluto-Charon as a double planet, so the moons are all said to be satellites of Pluto.
NASA.gov Video
**For more information:**
* [Moons of Pluto - Wikipedia](https://en.wikipedia.org/wiki/Moons_of_Pluto) | They orbit the barycenter of Pluto/ Charon, as there is no other place for them to orbit. Their orbit extends beyond the Charon, so thus the only stable orbit would go around both objects. See this image from [Wikipedia](https://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/Pluto_moon_P5_discovery_with_moons%27_orbits.jpg/470px-Pluto_moon_P5_discovery_with_moons%27_orbits.jpg).
 |
9,636 | As the center of gravity between Pluto and Charon is outside Pluto does Pluto's satellites other than Charon such as Nix, Hydra, Kerberos or Styx orbits around Pluto or the COG? | 2015/06/24 | [
"https://space.stackexchange.com/questions/9636",
"https://space.stackexchange.com",
"https://space.stackexchange.com/users/10579/"
] | There are potentially stable Pluto-centric\* orbits in the Pluto-Charon system, but so far [nothing has been detected](http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150528) in the *[Sailboat Island of Stability](https://space.stackexchange.com/questions/9307/what-is-a-sailboat-island-of-stability)* or anywhere else along the New Horizon's flyby trajectory. Otherwise, like the other three answers before me said; All of them, Pluto, Charon, Nix, Hydra, Styx and Kerberos orbit a common center of gravity, the barycenter, that's slightly outside of Pluto's body:
Animation source: [New Horizon's News Center](http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150429) (see both Pluto-centric and Barycentric animations there)
---
\*Even any other Pluto-centric orbits around Pluto but not also around Charon or any other satellites in the system would technically orbit around the system's common barycenter, but on top of that also be periodically (resonant orbits) or chaotically perturbed by gravitational influence of Charon and other satellites, so their orbital focus wouldn't be exactly at the common barycenter exactly all of the time. But on average, over time, and assuming they're not perturbed out of the system or hitting any other body, yes. Even multiple focal points of S-type orbits would converge at the barycenter of the Pluto-Charon system. | They orbit the barycenter of Pluto/ Charon, as there is no other place for them to orbit. Their orbit extends beyond the Charon, so thus the only stable orbit would go around both objects. See this image from [Wikipedia](https://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/Pluto_moon_P5_discovery_with_moons%27_orbits.jpg/470px-Pluto_moon_P5_discovery_with_moons%27_orbits.jpg).
 |
9,636 | As the center of gravity between Pluto and Charon is outside Pluto does Pluto's satellites other than Charon such as Nix, Hydra, Kerberos or Styx orbits around Pluto or the COG? | 2015/06/24 | [
"https://space.stackexchange.com/questions/9636",
"https://space.stackexchange.com",
"https://space.stackexchange.com/users/10579/"
] | The other moons orbit around both Pluto and Charon, so in a way it is accurate to say that they orbit the Pluto-Charon system rather than just Pluto, since Pluto and Charon orbit a center of gravity outside of Pluto. For now, the IAU has not pursued classifying Pluto-Charon as a double planet, so the moons are all said to be satellites of Pluto.
NASA.gov Video
**For more information:**
* [Moons of Pluto - Wikipedia](https://en.wikipedia.org/wiki/Moons_of_Pluto) | **The four moons (Nix, Hydra, Kerberos and Styx) all orbit around the centre-of-gravity of the Pluto-Charon binary system.**
Image from the Hubble Space Telescope highlighting the orbits of the four moons. You can clearly see that they are orbiting the barycentre of the system. (Courtesy [Wikimedia](https://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/Pluto_moon_P5_discovery_with_moons%27_orbits.jpg/470px-Pluto_moon_P5_discovery_with_moons%27_orbits.jpg))
More details about the exact orbits of the moons will come out soon, as the **New Horizons** probe sends back data. |
9,636 | As the center of gravity between Pluto and Charon is outside Pluto does Pluto's satellites other than Charon such as Nix, Hydra, Kerberos or Styx orbits around Pluto or the COG? | 2015/06/24 | [
"https://space.stackexchange.com/questions/9636",
"https://space.stackexchange.com",
"https://space.stackexchange.com/users/10579/"
] | The other moons orbit around both Pluto and Charon, so in a way it is accurate to say that they orbit the Pluto-Charon system rather than just Pluto, since Pluto and Charon orbit a center of gravity outside of Pluto. For now, the IAU has not pursued classifying Pluto-Charon as a double planet, so the moons are all said to be satellites of Pluto.
NASA.gov Video
**For more information:**
* [Moons of Pluto - Wikipedia](https://en.wikipedia.org/wiki/Moons_of_Pluto) | There are potentially stable Pluto-centric\* orbits in the Pluto-Charon system, but so far [nothing has been detected](http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150528) in the *[Sailboat Island of Stability](https://space.stackexchange.com/questions/9307/what-is-a-sailboat-island-of-stability)* or anywhere else along the New Horizon's flyby trajectory. Otherwise, like the other three answers before me said; All of them, Pluto, Charon, Nix, Hydra, Styx and Kerberos orbit a common center of gravity, the barycenter, that's slightly outside of Pluto's body:
Animation source: [New Horizon's News Center](http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150429) (see both Pluto-centric and Barycentric animations there)
---
\*Even any other Pluto-centric orbits around Pluto but not also around Charon or any other satellites in the system would technically orbit around the system's common barycenter, but on top of that also be periodically (resonant orbits) or chaotically perturbed by gravitational influence of Charon and other satellites, so their orbital focus wouldn't be exactly at the common barycenter exactly all of the time. But on average, over time, and assuming they're not perturbed out of the system or hitting any other body, yes. Even multiple focal points of S-type orbits would converge at the barycenter of the Pluto-Charon system. |
9,636 | As the center of gravity between Pluto and Charon is outside Pluto does Pluto's satellites other than Charon such as Nix, Hydra, Kerberos or Styx orbits around Pluto or the COG? | 2015/06/24 | [
"https://space.stackexchange.com/questions/9636",
"https://space.stackexchange.com",
"https://space.stackexchange.com/users/10579/"
] | The other moons orbit around both Pluto and Charon, so in a way it is accurate to say that they orbit the Pluto-Charon system rather than just Pluto, since Pluto and Charon orbit a center of gravity outside of Pluto. For now, the IAU has not pursued classifying Pluto-Charon as a double planet, so the moons are all said to be satellites of Pluto.
NASA.gov Video
**For more information:**
* [Moons of Pluto - Wikipedia](https://en.wikipedia.org/wiki/Moons_of_Pluto) | TLDR: *If we feel we have to mention Charon every time we speak of the Plutonian system, then we should give the same privilege to all the other moons as well, as even they contribute to the COG; even if, admitedly, not to the extent of being able to move the COG to inside or outside of Pluto itself. So, we would have to say that Nix orbits the COG of the Pluto-Charon-Styx-Nix-Kerberos-Hydra system, and that sounds clumsy. So we usually say that Nix orbits Pluto.*
I'm not a physicist, but rather a logician and linguist by education. So let me try a logical analysis of the question to complement the existing great answers. The question sounds to me like "Does Earth orbit the Sun, or the COG of the Sun-Jupiter system?"
Whether the center of gravity is inside or outside of the heaviest body in the system has little bearing on the answer. The center of the solar system is frequently outside of the Sun, depending on how the planets are distributed at the time.
Whether we speak of the whole Plutonian system as a planet with moons, dwarf planet with moons, or a double dwarf planet with moons, is an almost arbitrary convention and we (non-physicists) have IAU to tell us what's the standard terminology of the day.
Even the "Plutonian system" is just a figure of speech, a simplification. It was discovered the way it was because Uranus and Neptune are paying occasional visits to the club, too, presumably perturbing the moons unevenly in the process. |
9,636 | As the center of gravity between Pluto and Charon is outside Pluto does Pluto's satellites other than Charon such as Nix, Hydra, Kerberos or Styx orbits around Pluto or the COG? | 2015/06/24 | [
"https://space.stackexchange.com/questions/9636",
"https://space.stackexchange.com",
"https://space.stackexchange.com/users/10579/"
] | There are potentially stable Pluto-centric\* orbits in the Pluto-Charon system, but so far [nothing has been detected](http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150528) in the *[Sailboat Island of Stability](https://space.stackexchange.com/questions/9307/what-is-a-sailboat-island-of-stability)* or anywhere else along the New Horizon's flyby trajectory. Otherwise, like the other three answers before me said; All of them, Pluto, Charon, Nix, Hydra, Styx and Kerberos orbit a common center of gravity, the barycenter, that's slightly outside of Pluto's body:
Animation source: [New Horizon's News Center](http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150429) (see both Pluto-centric and Barycentric animations there)
---
\*Even any other Pluto-centric orbits around Pluto but not also around Charon or any other satellites in the system would technically orbit around the system's common barycenter, but on top of that also be periodically (resonant orbits) or chaotically perturbed by gravitational influence of Charon and other satellites, so their orbital focus wouldn't be exactly at the common barycenter exactly all of the time. But on average, over time, and assuming they're not perturbed out of the system or hitting any other body, yes. Even multiple focal points of S-type orbits would converge at the barycenter of the Pluto-Charon system. | **The four moons (Nix, Hydra, Kerberos and Styx) all orbit around the centre-of-gravity of the Pluto-Charon binary system.**
Image from the Hubble Space Telescope highlighting the orbits of the four moons. You can clearly see that they are orbiting the barycentre of the system. (Courtesy [Wikimedia](https://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/Pluto_moon_P5_discovery_with_moons%27_orbits.jpg/470px-Pluto_moon_P5_discovery_with_moons%27_orbits.jpg))
More details about the exact orbits of the moons will come out soon, as the **New Horizons** probe sends back data. |
9,636 | As the center of gravity between Pluto and Charon is outside Pluto does Pluto's satellites other than Charon such as Nix, Hydra, Kerberos or Styx orbits around Pluto or the COG? | 2015/06/24 | [
"https://space.stackexchange.com/questions/9636",
"https://space.stackexchange.com",
"https://space.stackexchange.com/users/10579/"
] | There are potentially stable Pluto-centric\* orbits in the Pluto-Charon system, but so far [nothing has been detected](http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150528) in the *[Sailboat Island of Stability](https://space.stackexchange.com/questions/9307/what-is-a-sailboat-island-of-stability)* or anywhere else along the New Horizon's flyby trajectory. Otherwise, like the other three answers before me said; All of them, Pluto, Charon, Nix, Hydra, Styx and Kerberos orbit a common center of gravity, the barycenter, that's slightly outside of Pluto's body:
Animation source: [New Horizon's News Center](http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150429) (see both Pluto-centric and Barycentric animations there)
---
\*Even any other Pluto-centric orbits around Pluto but not also around Charon or any other satellites in the system would technically orbit around the system's common barycenter, but on top of that also be periodically (resonant orbits) or chaotically perturbed by gravitational influence of Charon and other satellites, so their orbital focus wouldn't be exactly at the common barycenter exactly all of the time. But on average, over time, and assuming they're not perturbed out of the system or hitting any other body, yes. Even multiple focal points of S-type orbits would converge at the barycenter of the Pluto-Charon system. | TLDR: *If we feel we have to mention Charon every time we speak of the Plutonian system, then we should give the same privilege to all the other moons as well, as even they contribute to the COG; even if, admitedly, not to the extent of being able to move the COG to inside or outside of Pluto itself. So, we would have to say that Nix orbits the COG of the Pluto-Charon-Styx-Nix-Kerberos-Hydra system, and that sounds clumsy. So we usually say that Nix orbits Pluto.*
I'm not a physicist, but rather a logician and linguist by education. So let me try a logical analysis of the question to complement the existing great answers. The question sounds to me like "Does Earth orbit the Sun, or the COG of the Sun-Jupiter system?"
Whether the center of gravity is inside or outside of the heaviest body in the system has little bearing on the answer. The center of the solar system is frequently outside of the Sun, depending on how the planets are distributed at the time.
Whether we speak of the whole Plutonian system as a planet with moons, dwarf planet with moons, or a double dwarf planet with moons, is an almost arbitrary convention and we (non-physicists) have IAU to tell us what's the standard terminology of the day.
Even the "Plutonian system" is just a figure of speech, a simplification. It was discovered the way it was because Uranus and Neptune are paying occasional visits to the club, too, presumably perturbing the moons unevenly in the process. |
136,387 | I was reading a book - "Steps to Understanding" by L.A. Hill - when i saw the sentence below:
>
> One day he saw an advertisement for a suitable house in Hampshire which was claimed to be **within a stone's throw** of a railway station.
>
>
>
I know what "throw" means. I was expecting to see a kind of distance determiner after the word "within".
But what does exactly mean to be "within a stone's throw of somewhere"? How much is this distance? What does it mean? Does it mean that If someone throws a stone from the train station, The house is in the range of the distance which the stone travels? | 2017/07/14 | [
"https://ell.stackexchange.com/questions/136387",
"https://ell.stackexchange.com",
"https://ell.stackexchange.com/users/37346/"
] | No, it's not meant to be taken literally. It simply means *close (by)*. There is no fixed distance that constitutes a "stone's throw", much like how "close" or "near" are not fixed.
>
> [**within a stone's throw (of something)**](http://idioms.thefreedictionary.com/within+a+stone%27s+throw) and (just) a stone's throw away (from something); (just) a stone's throw (from something)
>
> Fig. very close (to something). (Possibly as close as the distance one could throw a stone. It usually refers to a distance much greater than one could throw a stone.) *The police department was located within a stone's throw of our house. We live in Carbondale, and that's just a stone's throw away from the Mississippi River. Come visit. We live just a stone's throw away.*
>
> (TFD)
>
>
> | "stone's throw" refers to a short distance away. Obviously most of us can't throw a stone too far, so people use this phrase to describe two places that are not far apart.
>
> **a stone’s throw (away)**
>
>
> a short distance:
>
>
> *The animal was sitting just a stone's throw away from us*.
>
>
> *The lodge is within a stone’s throw of the ski slopes*.
>
>
> Source: [Cambridge Dictionary](http://dictionary.cambridge.org/us/dictionary/english/a-stone-s-throw-away)
>
>
> |
43,306 | [](https://i.stack.imgur.com/LRUFk.jpg)I have a very steep hill on my route which levels out after about 2 km. The first quarter is extremely steep and shortly after I enter it the bike skips around a little bit and by the time I'm at the bottom I'm gripping the handle bars and working pretty hard to keep it under control.
Is this a normal issue or is it indicative of problems with the bike? It happens both with my mountain bike and the touring bike. Less on the 29'er mountain bike perhaps due to the wider tyres and less twitchy handling.
There is a lot of acceleration right from the start going down.
Clarification:- I'm not concerned with other people's safety or traffic, my question is more about at what speed does my bike become unhandleable and/or fall to pieces. | 2016/10/20 | [
"https://bicycles.stackexchange.com/questions/43306",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/25176/"
] | High speed stability can be dramatically affected by the geometry of the bike in question. There's a chance that the head angle on your 29'er is slacker which should give greater stability.
I know that on a car at certain rpm's you can get vibration through the car if a wheel is not correctly balanced. You might want to check over your wheels and make sure spoke tension is correct for safety's sake.
I don't know what bike you're riding and I'm not a road rider really but perhaps there's something in your posture that can aid stability. On an MTB you'd hang further out the back to keep your weight centred over the bottom bracket. | There is no limit to safe downhill speed on your bike. The limit is when you come off your bike. In which case even a low speed crash of 20 to 30 mph can be pretty nasty on chip and seal type surfaces or where there are obstacles (oncoming traffic anyone?).
You can ride a modern road bike up to 60 mph, even a little more but I would say that it is not safe to ride at that speed with nothing but spandex and a lightweight crash helmet. |
43,306 | [](https://i.stack.imgur.com/LRUFk.jpg)I have a very steep hill on my route which levels out after about 2 km. The first quarter is extremely steep and shortly after I enter it the bike skips around a little bit and by the time I'm at the bottom I'm gripping the handle bars and working pretty hard to keep it under control.
Is this a normal issue or is it indicative of problems with the bike? It happens both with my mountain bike and the touring bike. Less on the 29'er mountain bike perhaps due to the wider tyres and less twitchy handling.
There is a lot of acceleration right from the start going down.
Clarification:- I'm not concerned with other people's safety or traffic, my question is more about at what speed does my bike become unhandleable and/or fall to pieces. | 2016/10/20 | [
"https://bicycles.stackexchange.com/questions/43306",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/25176/"
] | High speed stability can be dramatically affected by the geometry of the bike in question. There's a chance that the head angle on your 29'er is slacker which should give greater stability.
I know that on a car at certain rpm's you can get vibration through the car if a wheel is not correctly balanced. You might want to check over your wheels and make sure spoke tension is correct for safety's sake.
I don't know what bike you're riding and I'm not a road rider really but perhaps there's something in your posture that can aid stability. On an MTB you'd hang further out the back to keep your weight centred over the bottom bracket. | I don't think there's anything like a **specific** safe speed for going downhill. From my experience there are many reasons for a bike becoming unhandlable when going downhill:
**your bike**: i'd say the main factors that enable you to go downhill fast *& safe* are:
* frame & fork: a super stiff carbon frame or an aluminium frame tend to be less shakey on a fast downhill ride. the same is valid for the fork. however, the stiffer your frame, the more sensitive it is to bumps etc.
* wheels: aero designed wheels (i.e. "high" rims and flat spokes) allow higher levels of control at high speeds.
* tyres: the wider the more friction and more absorption of bumps.
* suspension: generally hinder control at high speeds, however if the road is very uneven it might still be of benefit nontheless
* handle bar: wider handle bars and a longer stem make your bike less twitchy at high speeds
* stance: the wider your bottom bracket / the pedals, the smaller becomes the issue of balance at high speeds
**fear / the size of your balls**: right after the hardware, i'd say the software (as in your brains) determine a safe downhill speed.
**the road**: not gonna go to details here, that has been discussed in may ways in the comments.
*summing up*: if your bike is properly set up and well maintained, i don't assume it would just fall apart when going fast. |
43,306 | [](https://i.stack.imgur.com/LRUFk.jpg)I have a very steep hill on my route which levels out after about 2 km. The first quarter is extremely steep and shortly after I enter it the bike skips around a little bit and by the time I'm at the bottom I'm gripping the handle bars and working pretty hard to keep it under control.
Is this a normal issue or is it indicative of problems with the bike? It happens both with my mountain bike and the touring bike. Less on the 29'er mountain bike perhaps due to the wider tyres and less twitchy handling.
There is a lot of acceleration right from the start going down.
Clarification:- I'm not concerned with other people's safety or traffic, my question is more about at what speed does my bike become unhandleable and/or fall to pieces. | 2016/10/20 | [
"https://bicycles.stackexchange.com/questions/43306",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/25176/"
] | The maximum safe speed is the speed where you still have control you think is needed.
There are levels of control
* Can you stop if a car suddenly reverses out of a driveway?
This is the highest level of control; it means we'd never exceed about **25kph (16mph)** on the flat. Obviously we frequently exceed that, and so we're trusting that such intrusions into our "road space" will not occur *on this ride*.
* Can you swerve to avoid a small child or animal that suddenly runs onto the road?
Since such intruders are notoriously unpredictable, we also need to brake *and* swerve. If I know there are kids / dogs on the loose, I slow down to that 25kph level, or slower. But if it's reasonably open road I figure it's reasonably safe to clock **40kph (25mph)**. I've encountered oncoming cars in my lane as I round a bend on a descent at this speed, and there's plenty of time to evaluate my options, brake, and take evasive action (time flows *really* slowly in such cases).
* If the road is *really* clear, i.e. you can see well to the sides, and a long way in front.
In this case we can easily do **60kph (35mph)**. Around this point (and faster) some rider / bike combinations can experience shaking, which can be quite frightening. You need to experiment a bit to learn what's going on. In many cases resting your knee against the frame seems to dampen the shakes. In other cases I've had success *relaxing* my grip on the handlebars - this seems to suggest that it was my fear of death grip on the bars causing the wobbles :-)
* Ok the road is clear, and you're feeling lucky. How fast can you go?
If we keep going faster, it seems we pass the zone where the speed wobbles occur. If you are not a pro (being paid to do it), and are not confident, or are just a sensible person **don't do it**. However, I can confess to cracking 120kph (70mph) on a descent on a road bike. I found that as I went faster the bike became more stable, I'm guessing from the gyroscopic effect of the wheels. The same effect seemed to make turns more difficult. The first time I also found it was *extremely* hard to see properly, since I wasn't wearing any eye protection. And it took over 400 meters to stop on the flat. We can be sure that if any of the above mentioned road intrusions occurred then I would have been toast.
After all that, given the pictures you've posted, I would recommend at top speed of **30 to 40kph (16 to 25mph)**, because it looks like a residential area. Even that may be too fast, especially because of the incline, which means your center of gravity is higher and so you have less braking capacity. | There is no limit to safe downhill speed on your bike. The limit is when you come off your bike. In which case even a low speed crash of 20 to 30 mph can be pretty nasty on chip and seal type surfaces or where there are obstacles (oncoming traffic anyone?).
You can ride a modern road bike up to 60 mph, even a little more but I would say that it is not safe to ride at that speed with nothing but spandex and a lightweight crash helmet. |
43,306 | [](https://i.stack.imgur.com/LRUFk.jpg)I have a very steep hill on my route which levels out after about 2 km. The first quarter is extremely steep and shortly after I enter it the bike skips around a little bit and by the time I'm at the bottom I'm gripping the handle bars and working pretty hard to keep it under control.
Is this a normal issue or is it indicative of problems with the bike? It happens both with my mountain bike and the touring bike. Less on the 29'er mountain bike perhaps due to the wider tyres and less twitchy handling.
There is a lot of acceleration right from the start going down.
Clarification:- I'm not concerned with other people's safety or traffic, my question is more about at what speed does my bike become unhandleable and/or fall to pieces. | 2016/10/20 | [
"https://bicycles.stackexchange.com/questions/43306",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/25176/"
] | I don't think there's anything like a **specific** safe speed for going downhill. From my experience there are many reasons for a bike becoming unhandlable when going downhill:
**your bike**: i'd say the main factors that enable you to go downhill fast *& safe* are:
* frame & fork: a super stiff carbon frame or an aluminium frame tend to be less shakey on a fast downhill ride. the same is valid for the fork. however, the stiffer your frame, the more sensitive it is to bumps etc.
* wheels: aero designed wheels (i.e. "high" rims and flat spokes) allow higher levels of control at high speeds.
* tyres: the wider the more friction and more absorption of bumps.
* suspension: generally hinder control at high speeds, however if the road is very uneven it might still be of benefit nontheless
* handle bar: wider handle bars and a longer stem make your bike less twitchy at high speeds
* stance: the wider your bottom bracket / the pedals, the smaller becomes the issue of balance at high speeds
**fear / the size of your balls**: right after the hardware, i'd say the software (as in your brains) determine a safe downhill speed.
**the road**: not gonna go to details here, that has been discussed in may ways in the comments.
*summing up*: if your bike is properly set up and well maintained, i don't assume it would just fall apart when going fast. | There is no limit to safe downhill speed on your bike. The limit is when you come off your bike. In which case even a low speed crash of 20 to 30 mph can be pretty nasty on chip and seal type surfaces or where there are obstacles (oncoming traffic anyone?).
You can ride a modern road bike up to 60 mph, even a little more but I would say that it is not safe to ride at that speed with nothing but spandex and a lightweight crash helmet. |
43,306 | [](https://i.stack.imgur.com/LRUFk.jpg)I have a very steep hill on my route which levels out after about 2 km. The first quarter is extremely steep and shortly after I enter it the bike skips around a little bit and by the time I'm at the bottom I'm gripping the handle bars and working pretty hard to keep it under control.
Is this a normal issue or is it indicative of problems with the bike? It happens both with my mountain bike and the touring bike. Less on the 29'er mountain bike perhaps due to the wider tyres and less twitchy handling.
There is a lot of acceleration right from the start going down.
Clarification:- I'm not concerned with other people's safety or traffic, my question is more about at what speed does my bike become unhandleable and/or fall to pieces. | 2016/10/20 | [
"https://bicycles.stackexchange.com/questions/43306",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/25176/"
] | The maximum safe speed is the speed where you still have control you think is needed.
There are levels of control
* Can you stop if a car suddenly reverses out of a driveway?
This is the highest level of control; it means we'd never exceed about **25kph (16mph)** on the flat. Obviously we frequently exceed that, and so we're trusting that such intrusions into our "road space" will not occur *on this ride*.
* Can you swerve to avoid a small child or animal that suddenly runs onto the road?
Since such intruders are notoriously unpredictable, we also need to brake *and* swerve. If I know there are kids / dogs on the loose, I slow down to that 25kph level, or slower. But if it's reasonably open road I figure it's reasonably safe to clock **40kph (25mph)**. I've encountered oncoming cars in my lane as I round a bend on a descent at this speed, and there's plenty of time to evaluate my options, brake, and take evasive action (time flows *really* slowly in such cases).
* If the road is *really* clear, i.e. you can see well to the sides, and a long way in front.
In this case we can easily do **60kph (35mph)**. Around this point (and faster) some rider / bike combinations can experience shaking, which can be quite frightening. You need to experiment a bit to learn what's going on. In many cases resting your knee against the frame seems to dampen the shakes. In other cases I've had success *relaxing* my grip on the handlebars - this seems to suggest that it was my fear of death grip on the bars causing the wobbles :-)
* Ok the road is clear, and you're feeling lucky. How fast can you go?
If we keep going faster, it seems we pass the zone where the speed wobbles occur. If you are not a pro (being paid to do it), and are not confident, or are just a sensible person **don't do it**. However, I can confess to cracking 120kph (70mph) on a descent on a road bike. I found that as I went faster the bike became more stable, I'm guessing from the gyroscopic effect of the wheels. The same effect seemed to make turns more difficult. The first time I also found it was *extremely* hard to see properly, since I wasn't wearing any eye protection. And it took over 400 meters to stop on the flat. We can be sure that if any of the above mentioned road intrusions occurred then I would have been toast.
After all that, given the pictures you've posted, I would recommend at top speed of **30 to 40kph (16 to 25mph)**, because it looks like a residential area. Even that may be too fast, especially because of the incline, which means your center of gravity is higher and so you have less braking capacity. | I don't think there's anything like a **specific** safe speed for going downhill. From my experience there are many reasons for a bike becoming unhandlable when going downhill:
**your bike**: i'd say the main factors that enable you to go downhill fast *& safe* are:
* frame & fork: a super stiff carbon frame or an aluminium frame tend to be less shakey on a fast downhill ride. the same is valid for the fork. however, the stiffer your frame, the more sensitive it is to bumps etc.
* wheels: aero designed wheels (i.e. "high" rims and flat spokes) allow higher levels of control at high speeds.
* tyres: the wider the more friction and more absorption of bumps.
* suspension: generally hinder control at high speeds, however if the road is very uneven it might still be of benefit nontheless
* handle bar: wider handle bars and a longer stem make your bike less twitchy at high speeds
* stance: the wider your bottom bracket / the pedals, the smaller becomes the issue of balance at high speeds
**fear / the size of your balls**: right after the hardware, i'd say the software (as in your brains) determine a safe downhill speed.
**the road**: not gonna go to details here, that has been discussed in may ways in the comments.
*summing up*: if your bike is properly set up and well maintained, i don't assume it would just fall apart when going fast. |
12,767 | I understand there is an awful lot of Quantitative Math required for statistical arbitrage/algorithmic trading. However, would someone "in the know" be able to tell me whether there is less quantitative requirement for being a market-maker?
My (simplistic) viewpoint on market making is you simply want to keep quoting, collect the exchange rebates and if you get hit on one side of the bidask spread you need to hedge that trade. Using this (admitedly simplistic) viewpoint, I got the impression there was far less PhD-level mathematics involved than stat arb/algo trading?
I ask because myself and a group of friends are low-latency programmers and we are pondering whether we could realistically start up a small market-making business and utilise our low-latency experience. However, with our speciality on the technical side and no PhD mathematicians, we weren't sure how plausible it was.
Assuming it was plausible would you suggest beginning with a smaller exchange/market? Straight equities vs index futures/options, does it matter?
Any useful advice would be most welcome. | 2014/06/23 | [
"https://quant.stackexchange.com/questions/12767",
"https://quant.stackexchange.com",
"https://quant.stackexchange.com/users/6089/"
] | Successful strategies in both areas can have the same math requirement. It just depends on the algorithm. PhD level mathematics is not a requirement in either area, despite the impression you may get from academic papers (note that a lot of these papers use math to build a sim market, which is completely dislocated from what a researcher needs to do). I feel that, if anyone is bogged down in esoteric math in either area, [their strategy is about to break down](http://arxiv.org/abs/1402.1281).
What you primarily need to be good at is data analysis and statistical modelling, and being able to come up with good ideas.
Why do you guys think you will be successful without a research background? I have spoken to a few low-latency software engineers who hadn't had research exposure yet and I can give a 100% guarantee that they would not have made a cent if they were out on their own and had to build strategies. Trading is an actual profession and an actual skillset that is not as simple as "adjusting your quotes around the inside levels". Academic papers aren't going to help with strategy either (I haven't read something that would make money yet).
In summary, you should not be concerned about a lack of math ability (my position still applies if half you guys are math PhDs), you should be concerned about a lack of trading ability. | Unfortunately, the ability and tools to develop a low latency trading system are extremely commoditized and will be insufficient for you to make a living in this field. An overwhelming majority of electronic market makers are staffed 100% by PhDs because trading experience and research compose their primary differentiators, e.g.:
1. SIG EMM - 100% PhD.
2. DRW EMM - Almost 100% PhD.
3. Chopper EMM - Only 1 non-PhD.
4. Two Sigma EMM - About 80% PhD.
The list goes on. There are a few shops that hire mainly among those with B.Sc-level mathematics background, but these shops were also all started by former veterans of floor trading and/or early adopters of electronic trading, e.g.:
1. Optiver
2. Tower Research Capital
3. Virtu Financial
4. GETCO
5. IMC Financial Markets
...or late adopters who were former veterans from Citadel, Tower Research, SIG etc. and spun off, e.g.:
1. Hudson River Trading
2. Jane Street
3. Headlands Technologies
One will be very mistaken if he expects to take @lehalle's list of papers and some coding ability across the profitability hurdle. I wouldn't dream of doing so alone even though I wrote an entire custom UDP/TCP layer against reduced architecture in the early stages of my firm. You could downvote and ignore this advice, but I welcome you to inject a few dollars into the market. |
12,767 | I understand there is an awful lot of Quantitative Math required for statistical arbitrage/algorithmic trading. However, would someone "in the know" be able to tell me whether there is less quantitative requirement for being a market-maker?
My (simplistic) viewpoint on market making is you simply want to keep quoting, collect the exchange rebates and if you get hit on one side of the bidask spread you need to hedge that trade. Using this (admitedly simplistic) viewpoint, I got the impression there was far less PhD-level mathematics involved than stat arb/algo trading?
I ask because myself and a group of friends are low-latency programmers and we are pondering whether we could realistically start up a small market-making business and utilise our low-latency experience. However, with our speciality on the technical side and no PhD mathematicians, we weren't sure how plausible it was.
Assuming it was plausible would you suggest beginning with a smaller exchange/market? Straight equities vs index futures/options, does it matter?
Any useful advice would be most welcome. | 2014/06/23 | [
"https://quant.stackexchange.com/questions/12767",
"https://quant.stackexchange.com",
"https://quant.stackexchange.com/users/6089/"
] | Successful strategies in both areas can have the same math requirement. It just depends on the algorithm. PhD level mathematics is not a requirement in either area, despite the impression you may get from academic papers (note that a lot of these papers use math to build a sim market, which is completely dislocated from what a researcher needs to do). I feel that, if anyone is bogged down in esoteric math in either area, [their strategy is about to break down](http://arxiv.org/abs/1402.1281).
What you primarily need to be good at is data analysis and statistical modelling, and being able to come up with good ideas.
Why do you guys think you will be successful without a research background? I have spoken to a few low-latency software engineers who hadn't had research exposure yet and I can give a 100% guarantee that they would not have made a cent if they were out on their own and had to build strategies. Trading is an actual profession and an actual skillset that is not as simple as "adjusting your quotes around the inside levels". Academic papers aren't going to help with strategy either (I haven't read something that would make money yet).
In summary, you should not be concerned about a lack of math ability (my position still applies if half you guys are math PhDs), you should be concerned about a lack of trading ability. | No. All you need is to be naturally smart, and not lack common sense.
Well, clearly, a bare minimum of education (the 4 operations should suffice) ;-)
Also sometimes, too much specialized education may really be detrimental (it's common the case of Physics PhDs, who have an harmful tendency towards predictive models).
Usually, and generally speaking, a Statistics background is the best (clearly, most it's up to the individual. You will surely find clueless statisticians too, no doubt). |
12,767 | I understand there is an awful lot of Quantitative Math required for statistical arbitrage/algorithmic trading. However, would someone "in the know" be able to tell me whether there is less quantitative requirement for being a market-maker?
My (simplistic) viewpoint on market making is you simply want to keep quoting, collect the exchange rebates and if you get hit on one side of the bidask spread you need to hedge that trade. Using this (admitedly simplistic) viewpoint, I got the impression there was far less PhD-level mathematics involved than stat arb/algo trading?
I ask because myself and a group of friends are low-latency programmers and we are pondering whether we could realistically start up a small market-making business and utilise our low-latency experience. However, with our speciality on the technical side and no PhD mathematicians, we weren't sure how plausible it was.
Assuming it was plausible would you suggest beginning with a smaller exchange/market? Straight equities vs index futures/options, does it matter?
Any useful advice would be most welcome. | 2014/06/23 | [
"https://quant.stackexchange.com/questions/12767",
"https://quant.stackexchange.com",
"https://quant.stackexchange.com/users/6089/"
] | Successful strategies in both areas can have the same math requirement. It just depends on the algorithm. PhD level mathematics is not a requirement in either area, despite the impression you may get from academic papers (note that a lot of these papers use math to build a sim market, which is completely dislocated from what a researcher needs to do). I feel that, if anyone is bogged down in esoteric math in either area, [their strategy is about to break down](http://arxiv.org/abs/1402.1281).
What you primarily need to be good at is data analysis and statistical modelling, and being able to come up with good ideas.
Why do you guys think you will be successful without a research background? I have spoken to a few low-latency software engineers who hadn't had research exposure yet and I can give a 100% guarantee that they would not have made a cent if they were out on their own and had to build strategies. Trading is an actual profession and an actual skillset that is not as simple as "adjusting your quotes around the inside levels". Academic papers aren't going to help with strategy either (I haven't read something that would make money yet).
In summary, you should not be concerned about a lack of math ability (my position still applies if half you guys are math PhDs), you should be concerned about a lack of trading ability. | I think a lot of people look for PhDs are not only for their mathematical or quantitative skills, but also for their research mindset. It takes a lot of iterations, trying a lot of ideas most of which would not work to come up with a profitable trading strategy. Having a PhD becomes a sort of testament to the fact that you have the perseverance required to work on open problems and take it to conclusion. I not saying that mathematical skills are not required, but that it takes far more than mathematical skills. |
12,767 | I understand there is an awful lot of Quantitative Math required for statistical arbitrage/algorithmic trading. However, would someone "in the know" be able to tell me whether there is less quantitative requirement for being a market-maker?
My (simplistic) viewpoint on market making is you simply want to keep quoting, collect the exchange rebates and if you get hit on one side of the bidask spread you need to hedge that trade. Using this (admitedly simplistic) viewpoint, I got the impression there was far less PhD-level mathematics involved than stat arb/algo trading?
I ask because myself and a group of friends are low-latency programmers and we are pondering whether we could realistically start up a small market-making business and utilise our low-latency experience. However, with our speciality on the technical side and no PhD mathematicians, we weren't sure how plausible it was.
Assuming it was plausible would you suggest beginning with a smaller exchange/market? Straight equities vs index futures/options, does it matter?
Any useful advice would be most welcome. | 2014/06/23 | [
"https://quant.stackexchange.com/questions/12767",
"https://quant.stackexchange.com",
"https://quant.stackexchange.com/users/6089/"
] | The primary quant skill needed to make the market is **optimal control** (a typical paper is [Guéant, O., L, and J. Fernandez-Tapia (2013, September). Dealing with the inventory risk: a solution to the market making problem. Mathematics and Financial Economics 4 (7), 477-507](http://arxiv.org/abs/1105.3115)), because you need to control your inventory and adjust your quotes accordingly:
* be more aggressive on your long leg
* and less on your short one.
But it has to be done with respect to your cost function (how do you valuate the risk of having a position, the cost of your short inventory, the fees, what are you assumptions on the price moves, etc). In reality if you do that for a large institution the risk of your inventory would probably be measured on the whole book of the firm (it adds questions about correlations --thus Epps effect--, etc).
Moreover, you will need to **hedge your inventory**: if you make the market on derivatives, you will need to understand the marginal variations of their value with respect to changes in their underlying (i.e. the "greeks" stuff, see [Stoikov, S. and M. Saglam (2009). Option market making under inventory risk.](http://link.springer.com/article/10.1007/s11147-009-9036-3)).
Of course you need to have some knowledge in microstructure: Kyle ([Kyle, A. P. (1985). Continuous auctions and insider trading. Econometrica 53 (6), 1315-1335.](http://www.jstor.org/discover/10.2307/1913210?uid=3738016&uid=2&uid=4&sid=21104363615663)) and Glosten-Milgrom ([Glosten, L. R. and P. R. Milgrom (1985, March). Bid, ask and transaction prices in a specialist market with heterogeneously informed traders. Journal of Financial Economics 14 (1), 71-100.](http://www.sciencedirect.com/science/article/pii/0304405X85900443)) like literature: adverse selection, market impact, etc.
And since the devil is in the detail; you need to know order types, trading rules, etc.
By the way, I have a (long) list of papers on quant market making on [my citeulike account](http://www.citeulike.org/user/lehalle/tag/market-making) which is also stored [here](https://web.archive.org/web/2017*/http://www.citeulike.org/user/lehalle/tag/market-making) | Unfortunately, the ability and tools to develop a low latency trading system are extremely commoditized and will be insufficient for you to make a living in this field. An overwhelming majority of electronic market makers are staffed 100% by PhDs because trading experience and research compose their primary differentiators, e.g.:
1. SIG EMM - 100% PhD.
2. DRW EMM - Almost 100% PhD.
3. Chopper EMM - Only 1 non-PhD.
4. Two Sigma EMM - About 80% PhD.
The list goes on. There are a few shops that hire mainly among those with B.Sc-level mathematics background, but these shops were also all started by former veterans of floor trading and/or early adopters of electronic trading, e.g.:
1. Optiver
2. Tower Research Capital
3. Virtu Financial
4. GETCO
5. IMC Financial Markets
...or late adopters who were former veterans from Citadel, Tower Research, SIG etc. and spun off, e.g.:
1. Hudson River Trading
2. Jane Street
3. Headlands Technologies
One will be very mistaken if he expects to take @lehalle's list of papers and some coding ability across the profitability hurdle. I wouldn't dream of doing so alone even though I wrote an entire custom UDP/TCP layer against reduced architecture in the early stages of my firm. You could downvote and ignore this advice, but I welcome you to inject a few dollars into the market. |
12,767 | I understand there is an awful lot of Quantitative Math required for statistical arbitrage/algorithmic trading. However, would someone "in the know" be able to tell me whether there is less quantitative requirement for being a market-maker?
My (simplistic) viewpoint on market making is you simply want to keep quoting, collect the exchange rebates and if you get hit on one side of the bidask spread you need to hedge that trade. Using this (admitedly simplistic) viewpoint, I got the impression there was far less PhD-level mathematics involved than stat arb/algo trading?
I ask because myself and a group of friends are low-latency programmers and we are pondering whether we could realistically start up a small market-making business and utilise our low-latency experience. However, with our speciality on the technical side and no PhD mathematicians, we weren't sure how plausible it was.
Assuming it was plausible would you suggest beginning with a smaller exchange/market? Straight equities vs index futures/options, does it matter?
Any useful advice would be most welcome. | 2014/06/23 | [
"https://quant.stackexchange.com/questions/12767",
"https://quant.stackexchange.com",
"https://quant.stackexchange.com/users/6089/"
] | The primary quant skill needed to make the market is **optimal control** (a typical paper is [Guéant, O., L, and J. Fernandez-Tapia (2013, September). Dealing with the inventory risk: a solution to the market making problem. Mathematics and Financial Economics 4 (7), 477-507](http://arxiv.org/abs/1105.3115)), because you need to control your inventory and adjust your quotes accordingly:
* be more aggressive on your long leg
* and less on your short one.
But it has to be done with respect to your cost function (how do you valuate the risk of having a position, the cost of your short inventory, the fees, what are you assumptions on the price moves, etc). In reality if you do that for a large institution the risk of your inventory would probably be measured on the whole book of the firm (it adds questions about correlations --thus Epps effect--, etc).
Moreover, you will need to **hedge your inventory**: if you make the market on derivatives, you will need to understand the marginal variations of their value with respect to changes in their underlying (i.e. the "greeks" stuff, see [Stoikov, S. and M. Saglam (2009). Option market making under inventory risk.](http://link.springer.com/article/10.1007/s11147-009-9036-3)).
Of course you need to have some knowledge in microstructure: Kyle ([Kyle, A. P. (1985). Continuous auctions and insider trading. Econometrica 53 (6), 1315-1335.](http://www.jstor.org/discover/10.2307/1913210?uid=3738016&uid=2&uid=4&sid=21104363615663)) and Glosten-Milgrom ([Glosten, L. R. and P. R. Milgrom (1985, March). Bid, ask and transaction prices in a specialist market with heterogeneously informed traders. Journal of Financial Economics 14 (1), 71-100.](http://www.sciencedirect.com/science/article/pii/0304405X85900443)) like literature: adverse selection, market impact, etc.
And since the devil is in the detail; you need to know order types, trading rules, etc.
By the way, I have a (long) list of papers on quant market making on [my citeulike account](http://www.citeulike.org/user/lehalle/tag/market-making) which is also stored [here](https://web.archive.org/web/2017*/http://www.citeulike.org/user/lehalle/tag/market-making) | No. All you need is to be naturally smart, and not lack common sense.
Well, clearly, a bare minimum of education (the 4 operations should suffice) ;-)
Also sometimes, too much specialized education may really be detrimental (it's common the case of Physics PhDs, who have an harmful tendency towards predictive models).
Usually, and generally speaking, a Statistics background is the best (clearly, most it's up to the individual. You will surely find clueless statisticians too, no doubt). |
12,767 | I understand there is an awful lot of Quantitative Math required for statistical arbitrage/algorithmic trading. However, would someone "in the know" be able to tell me whether there is less quantitative requirement for being a market-maker?
My (simplistic) viewpoint on market making is you simply want to keep quoting, collect the exchange rebates and if you get hit on one side of the bidask spread you need to hedge that trade. Using this (admitedly simplistic) viewpoint, I got the impression there was far less PhD-level mathematics involved than stat arb/algo trading?
I ask because myself and a group of friends are low-latency programmers and we are pondering whether we could realistically start up a small market-making business and utilise our low-latency experience. However, with our speciality on the technical side and no PhD mathematicians, we weren't sure how plausible it was.
Assuming it was plausible would you suggest beginning with a smaller exchange/market? Straight equities vs index futures/options, does it matter?
Any useful advice would be most welcome. | 2014/06/23 | [
"https://quant.stackexchange.com/questions/12767",
"https://quant.stackexchange.com",
"https://quant.stackexchange.com/users/6089/"
] | The primary quant skill needed to make the market is **optimal control** (a typical paper is [Guéant, O., L, and J. Fernandez-Tapia (2013, September). Dealing with the inventory risk: a solution to the market making problem. Mathematics and Financial Economics 4 (7), 477-507](http://arxiv.org/abs/1105.3115)), because you need to control your inventory and adjust your quotes accordingly:
* be more aggressive on your long leg
* and less on your short one.
But it has to be done with respect to your cost function (how do you valuate the risk of having a position, the cost of your short inventory, the fees, what are you assumptions on the price moves, etc). In reality if you do that for a large institution the risk of your inventory would probably be measured on the whole book of the firm (it adds questions about correlations --thus Epps effect--, etc).
Moreover, you will need to **hedge your inventory**: if you make the market on derivatives, you will need to understand the marginal variations of their value with respect to changes in their underlying (i.e. the "greeks" stuff, see [Stoikov, S. and M. Saglam (2009). Option market making under inventory risk.](http://link.springer.com/article/10.1007/s11147-009-9036-3)).
Of course you need to have some knowledge in microstructure: Kyle ([Kyle, A. P. (1985). Continuous auctions and insider trading. Econometrica 53 (6), 1315-1335.](http://www.jstor.org/discover/10.2307/1913210?uid=3738016&uid=2&uid=4&sid=21104363615663)) and Glosten-Milgrom ([Glosten, L. R. and P. R. Milgrom (1985, March). Bid, ask and transaction prices in a specialist market with heterogeneously informed traders. Journal of Financial Economics 14 (1), 71-100.](http://www.sciencedirect.com/science/article/pii/0304405X85900443)) like literature: adverse selection, market impact, etc.
And since the devil is in the detail; you need to know order types, trading rules, etc.
By the way, I have a (long) list of papers on quant market making on [my citeulike account](http://www.citeulike.org/user/lehalle/tag/market-making) which is also stored [here](https://web.archive.org/web/2017*/http://www.citeulike.org/user/lehalle/tag/market-making) | I think a lot of people look for PhDs are not only for their mathematical or quantitative skills, but also for their research mindset. It takes a lot of iterations, trying a lot of ideas most of which would not work to come up with a profitable trading strategy. Having a PhD becomes a sort of testament to the fact that you have the perseverance required to work on open problems and take it to conclusion. I not saying that mathematical skills are not required, but that it takes far more than mathematical skills. |
12,767 | I understand there is an awful lot of Quantitative Math required for statistical arbitrage/algorithmic trading. However, would someone "in the know" be able to tell me whether there is less quantitative requirement for being a market-maker?
My (simplistic) viewpoint on market making is you simply want to keep quoting, collect the exchange rebates and if you get hit on one side of the bidask spread you need to hedge that trade. Using this (admitedly simplistic) viewpoint, I got the impression there was far less PhD-level mathematics involved than stat arb/algo trading?
I ask because myself and a group of friends are low-latency programmers and we are pondering whether we could realistically start up a small market-making business and utilise our low-latency experience. However, with our speciality on the technical side and no PhD mathematicians, we weren't sure how plausible it was.
Assuming it was plausible would you suggest beginning with a smaller exchange/market? Straight equities vs index futures/options, does it matter?
Any useful advice would be most welcome. | 2014/06/23 | [
"https://quant.stackexchange.com/questions/12767",
"https://quant.stackexchange.com",
"https://quant.stackexchange.com/users/6089/"
] | Unfortunately, the ability and tools to develop a low latency trading system are extremely commoditized and will be insufficient for you to make a living in this field. An overwhelming majority of electronic market makers are staffed 100% by PhDs because trading experience and research compose their primary differentiators, e.g.:
1. SIG EMM - 100% PhD.
2. DRW EMM - Almost 100% PhD.
3. Chopper EMM - Only 1 non-PhD.
4. Two Sigma EMM - About 80% PhD.
The list goes on. There are a few shops that hire mainly among those with B.Sc-level mathematics background, but these shops were also all started by former veterans of floor trading and/or early adopters of electronic trading, e.g.:
1. Optiver
2. Tower Research Capital
3. Virtu Financial
4. GETCO
5. IMC Financial Markets
...or late adopters who were former veterans from Citadel, Tower Research, SIG etc. and spun off, e.g.:
1. Hudson River Trading
2. Jane Street
3. Headlands Technologies
One will be very mistaken if he expects to take @lehalle's list of papers and some coding ability across the profitability hurdle. I wouldn't dream of doing so alone even though I wrote an entire custom UDP/TCP layer against reduced architecture in the early stages of my firm. You could downvote and ignore this advice, but I welcome you to inject a few dollars into the market. | No. All you need is to be naturally smart, and not lack common sense.
Well, clearly, a bare minimum of education (the 4 operations should suffice) ;-)
Also sometimes, too much specialized education may really be detrimental (it's common the case of Physics PhDs, who have an harmful tendency towards predictive models).
Usually, and generally speaking, a Statistics background is the best (clearly, most it's up to the individual. You will surely find clueless statisticians too, no doubt). |
12,767 | I understand there is an awful lot of Quantitative Math required for statistical arbitrage/algorithmic trading. However, would someone "in the know" be able to tell me whether there is less quantitative requirement for being a market-maker?
My (simplistic) viewpoint on market making is you simply want to keep quoting, collect the exchange rebates and if you get hit on one side of the bidask spread you need to hedge that trade. Using this (admitedly simplistic) viewpoint, I got the impression there was far less PhD-level mathematics involved than stat arb/algo trading?
I ask because myself and a group of friends are low-latency programmers and we are pondering whether we could realistically start up a small market-making business and utilise our low-latency experience. However, with our speciality on the technical side and no PhD mathematicians, we weren't sure how plausible it was.
Assuming it was plausible would you suggest beginning with a smaller exchange/market? Straight equities vs index futures/options, does it matter?
Any useful advice would be most welcome. | 2014/06/23 | [
"https://quant.stackexchange.com/questions/12767",
"https://quant.stackexchange.com",
"https://quant.stackexchange.com/users/6089/"
] | Unfortunately, the ability and tools to develop a low latency trading system are extremely commoditized and will be insufficient for you to make a living in this field. An overwhelming majority of electronic market makers are staffed 100% by PhDs because trading experience and research compose their primary differentiators, e.g.:
1. SIG EMM - 100% PhD.
2. DRW EMM - Almost 100% PhD.
3. Chopper EMM - Only 1 non-PhD.
4. Two Sigma EMM - About 80% PhD.
The list goes on. There are a few shops that hire mainly among those with B.Sc-level mathematics background, but these shops were also all started by former veterans of floor trading and/or early adopters of electronic trading, e.g.:
1. Optiver
2. Tower Research Capital
3. Virtu Financial
4. GETCO
5. IMC Financial Markets
...or late adopters who were former veterans from Citadel, Tower Research, SIG etc. and spun off, e.g.:
1. Hudson River Trading
2. Jane Street
3. Headlands Technologies
One will be very mistaken if he expects to take @lehalle's list of papers and some coding ability across the profitability hurdle. I wouldn't dream of doing so alone even though I wrote an entire custom UDP/TCP layer against reduced architecture in the early stages of my firm. You could downvote and ignore this advice, but I welcome you to inject a few dollars into the market. | I think a lot of people look for PhDs are not only for their mathematical or quantitative skills, but also for their research mindset. It takes a lot of iterations, trying a lot of ideas most of which would not work to come up with a profitable trading strategy. Having a PhD becomes a sort of testament to the fact that you have the perseverance required to work on open problems and take it to conclusion. I not saying that mathematical skills are not required, but that it takes far more than mathematical skills. |
106,379 | In the UK Visa application form, the question asks: Total Monthly Income from Savings and Investments. Do I put my total savings balance or the interest I receive from the savings? For example, in the Philippines, I have savings of say 1 million pesos, but this only earns very small interest of 3 thousand pesos per month. Do I write 1 Million, or do I write 3 thousand pesos? | 2017/12/06 | [
"https://travel.stackexchange.com/questions/106379",
"https://travel.stackexchange.com",
"https://travel.stackexchange.com/users/71223/"
] | 3,000. Or whatever the real figure is. The question asks about the income, not the capital. As an aside, most working age people in the UK and the Philippines get most or all of their income from work (wage or salary) not from investments so this won't seem strange to the visa office. | You should put your interest amount only. they are asking you about your income from your saving. do not put how much savings you have. kindly mention how much you get interest from your savings.so you should put 3 thousand pesos as per your details. |
5,039,402 | I've developed a web application which uses ASP.net 4.0 Routing. It's working fine without using Window Azure.
But when I use it with Window Azure, it's not working, giving me 404 not found error. Means routing is not working.
I've follows the link: <http://www.michaelckennedy.net/blog/2009/05/27/ASPNETRoutingInWindowsAzureUsingWebForms.aspx> and try to implement accordingly. It is working fine with framework 3.5
But the same thing I applied with framework 4.0 is not working. | 2011/02/18 | [
"https://Stackoverflow.com/questions/5039402",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/622847/"
] | By default the web role for asp.net web forms is created with an operating system image based on Windows Server 2008 but for MVC applications which support routing the web role image is based on Windows Server 2008 R2.
So by manually switching OS family from 1 to 2 in the service configuration file on my web role it is published on R2 instead and that solved the problem with routing for me (for web api beta on .net 4.0).
I guess that it contains some IIS configurations that allows routing that is not present in the default web forms role image.
I found the solution in this blog post (in german) <http://blog.jan-welker.de/2011/12/18/WindowsAzureASPNETWebforms40UndSystemWebRouting404Vorprogrammiert.aspx> and with some help of google translate I managed to solve the problem I had. | I was having this problem and it was driving me crazy.
The solution is to enable "HTTP Redirection":
Windows Features -> Internet Information Services -> Word Wide Web services -> Common HTTP Features |
51,315,818 | I'm trying to delete Service catalog portfolio on my account, but I'm getting following error:
>
> **Delete portfolio failed**
>
>
> Portfolio port-xxx still has associated Principals
>
>
> | 2018/07/12 | [
"https://Stackoverflow.com/questions/51315818",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/9350422/"
] | Delete all principles, shares, constraints and products and then you will be able to delete it. | We have faced the same issue and we have to remove the IAM roles that are associated with the portfolio. |
51,315,818 | I'm trying to delete Service catalog portfolio on my account, but I'm getting following error:
>
> **Delete portfolio failed**
>
>
> Portfolio port-xxx still has associated Principals
>
>
> | 2018/07/12 | [
"https://Stackoverflow.com/questions/51315818",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/9350422/"
] | Delete all principles, shares, constraints and products and then you will be able to delete it. | 1. First click on the Portfolio that you want to delete.
2. Goto the tab, Users and roles.
3. Select the associated user and delete it from the Portfolio one by one.
4. Now try to delete the Portfolio. |
50,523 | I have a Canon Powershot S100 and use Adobe Photoshop 5.1, up until this point I have just saved images on my camera jpeg but I decided to try saving as raw format as well. So I set my camera to save as raw and jpeg, and in Lightroom I selected Preferences:General:Treat JPEG files as separate photos so I could compare the jpeg with the raw version.
Because it was evening and I was at home I took a photo in my lounge and set the white-balance to Tungsten.
Now as I understand RAW format ignore certain options set on the camera such as white balance and has to be applied in post-processing so I was expecting to see two photos that were similar but different, and that the most obvious difference would be white balance. In Lightroom the colours were indeed different so I set white balance of the RAW file to Tungsten and instead of that changing the colours so they were similar it made the picture very yellow and it **looked hideous.**
Am I doing something wrong or is this a problem with the camera or Lightrooom. DO I need to process the files with something else before using them with Lightroom ?
\*\* Edited \*\*
Here are the files:
[Jpeg as copied from camera to lightroom](http://jthink.net/jaikoz/scratch/raw/jpeg.jpg)
[Raw as copied from camera to lightroom and immediately exported to jpeg](http://jthink.net/jaikoz/scratch/raw/raw.jpg)
[Raw as copied from camera to lightroom, tungsten whitebalance set and exported to jpg](http://jthink.net/jaikoz/scratch/raw/raw_after_tungsten.jpg) | 2014/05/24 | [
"https://photo.stackexchange.com/questions/50523",
"https://photo.stackexchange.com",
"https://photo.stackexchange.com/users/28237/"
] | The raw format is un-rendered, so you get to decide what the resulting pixels look like. If your comparing in camera rendered jpeg files, you can do far better to aim for what you want not what the camera provided as your goals.
If your expecting a "standard" rendering that is similar to a camera rendered jpeg file out of any raw file processor, that is not a realistic expectation. There is no standard rendering that is used bay any manufacturer of cameras or software. It's all "secret sauce" So make your own with the raw files your camera generates. Start experimenting with all of the controls in the raw file editor to see what they do. Eventually you will play it like a fine instrument. Right now it appears your not enjoying the song. | It's unclear to me why you set the white balance to Tungsten, didn't like the results, and now think this is a problem. You can -- *should* -- adjust the white balance to whatever you think looks good.
The biggest problem as I see it is your use of tungsten white balance: Is the light in your photo tungsten? More specifically, do you know the exact color temperature of your light? I think anywhere from 2900 to 3300 is considered "tungsten" but I bet if you drag the temperature adjustment between that range you'll see a clear difference. Does your light precisely align with the value assigned to Tungsten in Lightroom? Next, was that light in the room the *only* light? If you turned off that light was the room completely black? If there are other lights and/or if the room is not completely black without that tungsten light, then there is some color crossover to deal with. Simply, one single perfect white balance is not going to perfectly and magically make everything right -- and of course, that is the most typical situation to deal with.
What it comes down to is that working with the raw format gives you headroom to make these adjustments yourself. Lightroom can help you by giving you a good starting place (such as the various white balance presets) but it's still up to you to decide what looks good and how you want to further adjust it. |
50,523 | I have a Canon Powershot S100 and use Adobe Photoshop 5.1, up until this point I have just saved images on my camera jpeg but I decided to try saving as raw format as well. So I set my camera to save as raw and jpeg, and in Lightroom I selected Preferences:General:Treat JPEG files as separate photos so I could compare the jpeg with the raw version.
Because it was evening and I was at home I took a photo in my lounge and set the white-balance to Tungsten.
Now as I understand RAW format ignore certain options set on the camera such as white balance and has to be applied in post-processing so I was expecting to see two photos that were similar but different, and that the most obvious difference would be white balance. In Lightroom the colours were indeed different so I set white balance of the RAW file to Tungsten and instead of that changing the colours so they were similar it made the picture very yellow and it **looked hideous.**
Am I doing something wrong or is this a problem with the camera or Lightrooom. DO I need to process the files with something else before using them with Lightroom ?
\*\* Edited \*\*
Here are the files:
[Jpeg as copied from camera to lightroom](http://jthink.net/jaikoz/scratch/raw/jpeg.jpg)
[Raw as copied from camera to lightroom and immediately exported to jpeg](http://jthink.net/jaikoz/scratch/raw/raw.jpg)
[Raw as copied from camera to lightroom, tungsten whitebalance set and exported to jpg](http://jthink.net/jaikoz/scratch/raw/raw_after_tungsten.jpg) | 2014/05/24 | [
"https://photo.stackexchange.com/questions/50523",
"https://photo.stackexchange.com",
"https://photo.stackexchange.com/users/28237/"
] | The raw format is un-rendered, so you get to decide what the resulting pixels look like. If your comparing in camera rendered jpeg files, you can do far better to aim for what you want not what the camera provided as your goals.
If your expecting a "standard" rendering that is similar to a camera rendered jpeg file out of any raw file processor, that is not a realistic expectation. There is no standard rendering that is used bay any manufacturer of cameras or software. It's all "secret sauce" So make your own with the raw files your camera generates. Start experimenting with all of the controls in the raw file editor to see what they do. Eventually you will play it like a fine instrument. Right now it appears your not enjoying the song. | tl;dr : no. You do not need anything more than lightroom (in terms of software to process the file)
Transforming from a raw file (that is the pure sensor readings per pixel) to something that you are displaying on a monitor is a rather complex process that involves a lot of math, quite some information additionally to the sensor readings, a pinch of secret sauce, and the turning of a lot of knobs that are up to whoever does the development process.
(note that I am mostly playing with dng files, and some details may be different in vendor specific raw files, but ultimately the underlying principles are the same).
Leaving details such as demosaicing out, the main part of "raw development" is doing the math to transform from the sensors colorspace (like xy), to the target rgb one (like sRGB or AdobeRGB). Here we have generally two approaches:
A matrix (or two). Those transform the whole 3d colorspace into another by shifting, rotating, tilting etc. it. This has some drawbacks: A lot of transformations here are linear, but the sensor responses are not. Additionally the matrix is valid for a specific lighting only (often D55 or D65) and in case of different lighting, sometimes an interpolation (or even extrapolation) of the matrix calculations is done to attribute for different lighting.
A profile table. To account for the nonlinearity of some sensor reponses, there exist calibration profiles. You can find them in lightroom, somewhere in the lower parts of all the knobs. These are mostly large tables that were calculated from special image targets photographed under special light conditions. Also here you sometimes have dual profiles that allow for inter/extrapolation, which contain the data of the same target under different lighting conditions.
The dng format saves these matrices for the raw converter, along with white balance information that helps in applying the matrices. Depending on the camera, this information contains some actual sensor readings, or is just some user setting. In most raw development programs, this will just preset the white balance adjustment sliders! The aforementioned calibration tables are usually part of the raw developer, if present at all.
So how does this process relate to the one your camera creates jpegs with? Most likely not at all. E.g. my canon ixus 950is has a built in table that it uses to calculate the jpeg image, in a way quite different to what adobe lightroom does.
Perception of a good white balance is very subjective and depends on many things, even such as the color of your monitors framing. So you don't like what came out of your tungsten setting? Adjust the knobs until you find the image nice, and resemble what you saw at the point you took it. That is about all what counts. You don't want a graphical representation of sensor values, you want to capture and reproduce a moment, and tell people what *you* saw at that point. Call it artistic freedom if you want.
But of course starting of with something that is a quite accurate sensor reading won't hurt, so how can be best achieve that? Generally for P&S cameras I found it good to work with the "as shot" white balance setting. In your case, your camera and Lightroom probably just have a rather different meaning of what "Tungsten" actually means.
For best results, you might want to invest a bit in a [color checker passport](http://www.luminous-landscape.com/reviews/accessories/colorchecker-psssport.shtml) or similar thing to be able to create profiles yourself, tailored to the specific lighting condition you encountered. It can also help finding a proper white point. Just use the included gray card part, and tell lightroom this is neutral color. This can often lead to quick satisfactory results.
And also note that it is called "raw development" (and not conversion) for a reason: you need to give input and tell the process how you would like the photo to look like. Play with the knobs. |
50,523 | I have a Canon Powershot S100 and use Adobe Photoshop 5.1, up until this point I have just saved images on my camera jpeg but I decided to try saving as raw format as well. So I set my camera to save as raw and jpeg, and in Lightroom I selected Preferences:General:Treat JPEG files as separate photos so I could compare the jpeg with the raw version.
Because it was evening and I was at home I took a photo in my lounge and set the white-balance to Tungsten.
Now as I understand RAW format ignore certain options set on the camera such as white balance and has to be applied in post-processing so I was expecting to see two photos that were similar but different, and that the most obvious difference would be white balance. In Lightroom the colours were indeed different so I set white balance of the RAW file to Tungsten and instead of that changing the colours so they were similar it made the picture very yellow and it **looked hideous.**
Am I doing something wrong or is this a problem with the camera or Lightrooom. DO I need to process the files with something else before using them with Lightroom ?
\*\* Edited \*\*
Here are the files:
[Jpeg as copied from camera to lightroom](http://jthink.net/jaikoz/scratch/raw/jpeg.jpg)
[Raw as copied from camera to lightroom and immediately exported to jpeg](http://jthink.net/jaikoz/scratch/raw/raw.jpg)
[Raw as copied from camera to lightroom, tungsten whitebalance set and exported to jpg](http://jthink.net/jaikoz/scratch/raw/raw_after_tungsten.jpg) | 2014/05/24 | [
"https://photo.stackexchange.com/questions/50523",
"https://photo.stackexchange.com",
"https://photo.stackexchange.com/users/28237/"
] | I think your overthinking things. Every RAW file is TAGGED with a white balance value. The tag simply contains the Kelvin rating for the white balance. If you selected Tungsten in camera, then by default the image, when rendered with Lightroom, will be rendered with a Kelvin rating somewhere between 2800K and 3300K (depends on the camera.)
If you further changed your white balance bu selecting Tungsten from "As Shot", then yes, your white balance is going to be incorrect. Even the seemingly minor change from 3300K to 2800K is actually huge. One has a soft yellow-orange appearance (3300K), and the other has a deep orange appearance (2800K), and that's just relative to each other.
So, effectively, yes you are "double applying" a Tungsten white balance, since Lightroom is already applying whatever Kelvin rating was stored in the RAW metadata. If you like how the image WB is when left at "As Shot", then just leave it at "As Shot". If you want it to be more orange, choose "Tungsten". If you want it to be whiter, choose "Daylight". Pretty much as simple as that. | The raw format is un-rendered, so you get to decide what the resulting pixels look like. If your comparing in camera rendered jpeg files, you can do far better to aim for what you want not what the camera provided as your goals.
If your expecting a "standard" rendering that is similar to a camera rendered jpeg file out of any raw file processor, that is not a realistic expectation. There is no standard rendering that is used bay any manufacturer of cameras or software. It's all "secret sauce" So make your own with the raw files your camera generates. Start experimenting with all of the controls in the raw file editor to see what they do. Eventually you will play it like a fine instrument. Right now it appears your not enjoying the song. |
50,523 | I have a Canon Powershot S100 and use Adobe Photoshop 5.1, up until this point I have just saved images on my camera jpeg but I decided to try saving as raw format as well. So I set my camera to save as raw and jpeg, and in Lightroom I selected Preferences:General:Treat JPEG files as separate photos so I could compare the jpeg with the raw version.
Because it was evening and I was at home I took a photo in my lounge and set the white-balance to Tungsten.
Now as I understand RAW format ignore certain options set on the camera such as white balance and has to be applied in post-processing so I was expecting to see two photos that were similar but different, and that the most obvious difference would be white balance. In Lightroom the colours were indeed different so I set white balance of the RAW file to Tungsten and instead of that changing the colours so they were similar it made the picture very yellow and it **looked hideous.**
Am I doing something wrong or is this a problem with the camera or Lightrooom. DO I need to process the files with something else before using them with Lightroom ?
\*\* Edited \*\*
Here are the files:
[Jpeg as copied from camera to lightroom](http://jthink.net/jaikoz/scratch/raw/jpeg.jpg)
[Raw as copied from camera to lightroom and immediately exported to jpeg](http://jthink.net/jaikoz/scratch/raw/raw.jpg)
[Raw as copied from camera to lightroom, tungsten whitebalance set and exported to jpg](http://jthink.net/jaikoz/scratch/raw/raw_after_tungsten.jpg) | 2014/05/24 | [
"https://photo.stackexchange.com/questions/50523",
"https://photo.stackexchange.com",
"https://photo.stackexchange.com/users/28237/"
] | It all boils down to different meanings for the word "tungsten".
Lightroom (or Adobe Camera Raw) is expecting "tungsten photographic lighting" when you select the Tungsten white balance preset. That means photofloods (type A or P bulbs with high wattage ratings - typically 250W or 500W - and a life expectancy of about 20 hours) or photography-oriented tungsten-halogen (quartz) lights, such as the Lowel Omni or Tota, a redhead or blonde, or a Fresnel spot such as the Arri 650. These all have colour temperatures of 3200K, which is really quite hot (blue) compared to household lighting or utility work lights, but it is the colour of light that tungsten (type B) film, both for stills and cine, are designed to work with. ("Tungsten" LEDs designed for photography are also 3200K.) In order to use the Tungsten preset (or type B tungsten film), you would need to use an 82-series blue cooling filter (either 82B or 82C) on the camera to raise the apparent colour temperature of the lighting from the typical very low household lighting range (2800K-2900K) to 3200K - otherwise your photographs are going to come out quite yellow.
The "Tungsten" white balance setting on your camera is a different beast altogether. For one thing, a consumer camera is not going to start with the assumption that you are shooting under Certified Official Photographic Lighting. But there's more to it than that. Unless you are using a custom white balance, the white balance setting on your digital camera (assuming it's not positively ancient and not a cheap toy) is not an absolute setting; it's more of an "automatic white balance with constraints" sort of thing. You'll find that, brightness of the scene aside, you'll get more or less the same picture using the camera's Tungsten setting under 2900K household lighting, 3200K photo/cine lighting or household/utility halogen lighting, which is somewhere in the middle. (It's only when you mix the types that you'll have problems.) The camera will record not only the setting you selected, but the colour temperature (yellow/blue) and tint (green/magenta) it selected under that setting into the file.
It is those recorded numbers that Lightroom/ACR will use as the "As Shot" values. (With allowances for differences between Adobe's idea of a "pleasing rendition" and the camera maker's.) When you select the Tungsten preset in Lightroom, you are effectively saying "forget what the camera thinks, I was shooting under 3200K lighting". In this case, that's a bit of a whopper; you're off by *at least* 32 [mireds](http://en.wikipedia.org/wiki/Mired), about the value given by an 82B cooling filter, and probably more.
If you want to get close to what the camera would have given you by itself, you can use "As Shot" *plus* setting the camera profile to the appropriate choice (such as "Camera Vivid") rather than leaving the default Adobe camera profile in place. It won't be exact, since it's Adobe's interpretation of the camera maker's "secret sauce", but it's usually pretty close. Or you can use the eydropper and the sliders to make the picture look the way you want it to. | It's unclear to me why you set the white balance to Tungsten, didn't like the results, and now think this is a problem. You can -- *should* -- adjust the white balance to whatever you think looks good.
The biggest problem as I see it is your use of tungsten white balance: Is the light in your photo tungsten? More specifically, do you know the exact color temperature of your light? I think anywhere from 2900 to 3300 is considered "tungsten" but I bet if you drag the temperature adjustment between that range you'll see a clear difference. Does your light precisely align with the value assigned to Tungsten in Lightroom? Next, was that light in the room the *only* light? If you turned off that light was the room completely black? If there are other lights and/or if the room is not completely black without that tungsten light, then there is some color crossover to deal with. Simply, one single perfect white balance is not going to perfectly and magically make everything right -- and of course, that is the most typical situation to deal with.
What it comes down to is that working with the raw format gives you headroom to make these adjustments yourself. Lightroom can help you by giving you a good starting place (such as the various white balance presets) but it's still up to you to decide what looks good and how you want to further adjust it. |
50,523 | I have a Canon Powershot S100 and use Adobe Photoshop 5.1, up until this point I have just saved images on my camera jpeg but I decided to try saving as raw format as well. So I set my camera to save as raw and jpeg, and in Lightroom I selected Preferences:General:Treat JPEG files as separate photos so I could compare the jpeg with the raw version.
Because it was evening and I was at home I took a photo in my lounge and set the white-balance to Tungsten.
Now as I understand RAW format ignore certain options set on the camera such as white balance and has to be applied in post-processing so I was expecting to see two photos that were similar but different, and that the most obvious difference would be white balance. In Lightroom the colours were indeed different so I set white balance of the RAW file to Tungsten and instead of that changing the colours so they were similar it made the picture very yellow and it **looked hideous.**
Am I doing something wrong or is this a problem with the camera or Lightrooom. DO I need to process the files with something else before using them with Lightroom ?
\*\* Edited \*\*
Here are the files:
[Jpeg as copied from camera to lightroom](http://jthink.net/jaikoz/scratch/raw/jpeg.jpg)
[Raw as copied from camera to lightroom and immediately exported to jpeg](http://jthink.net/jaikoz/scratch/raw/raw.jpg)
[Raw as copied from camera to lightroom, tungsten whitebalance set and exported to jpg](http://jthink.net/jaikoz/scratch/raw/raw_after_tungsten.jpg) | 2014/05/24 | [
"https://photo.stackexchange.com/questions/50523",
"https://photo.stackexchange.com",
"https://photo.stackexchange.com/users/28237/"
] | I think your overthinking things. Every RAW file is TAGGED with a white balance value. The tag simply contains the Kelvin rating for the white balance. If you selected Tungsten in camera, then by default the image, when rendered with Lightroom, will be rendered with a Kelvin rating somewhere between 2800K and 3300K (depends on the camera.)
If you further changed your white balance bu selecting Tungsten from "As Shot", then yes, your white balance is going to be incorrect. Even the seemingly minor change from 3300K to 2800K is actually huge. One has a soft yellow-orange appearance (3300K), and the other has a deep orange appearance (2800K), and that's just relative to each other.
So, effectively, yes you are "double applying" a Tungsten white balance, since Lightroom is already applying whatever Kelvin rating was stored in the RAW metadata. If you like how the image WB is when left at "As Shot", then just leave it at "As Shot". If you want it to be more orange, choose "Tungsten". If you want it to be whiter, choose "Daylight". Pretty much as simple as that. | It's unclear to me why you set the white balance to Tungsten, didn't like the results, and now think this is a problem. You can -- *should* -- adjust the white balance to whatever you think looks good.
The biggest problem as I see it is your use of tungsten white balance: Is the light in your photo tungsten? More specifically, do you know the exact color temperature of your light? I think anywhere from 2900 to 3300 is considered "tungsten" but I bet if you drag the temperature adjustment between that range you'll see a clear difference. Does your light precisely align with the value assigned to Tungsten in Lightroom? Next, was that light in the room the *only* light? If you turned off that light was the room completely black? If there are other lights and/or if the room is not completely black without that tungsten light, then there is some color crossover to deal with. Simply, one single perfect white balance is not going to perfectly and magically make everything right -- and of course, that is the most typical situation to deal with.
What it comes down to is that working with the raw format gives you headroom to make these adjustments yourself. Lightroom can help you by giving you a good starting place (such as the various white balance presets) but it's still up to you to decide what looks good and how you want to further adjust it. |
50,523 | I have a Canon Powershot S100 and use Adobe Photoshop 5.1, up until this point I have just saved images on my camera jpeg but I decided to try saving as raw format as well. So I set my camera to save as raw and jpeg, and in Lightroom I selected Preferences:General:Treat JPEG files as separate photos so I could compare the jpeg with the raw version.
Because it was evening and I was at home I took a photo in my lounge and set the white-balance to Tungsten.
Now as I understand RAW format ignore certain options set on the camera such as white balance and has to be applied in post-processing so I was expecting to see two photos that were similar but different, and that the most obvious difference would be white balance. In Lightroom the colours were indeed different so I set white balance of the RAW file to Tungsten and instead of that changing the colours so they were similar it made the picture very yellow and it **looked hideous.**
Am I doing something wrong or is this a problem with the camera or Lightrooom. DO I need to process the files with something else before using them with Lightroom ?
\*\* Edited \*\*
Here are the files:
[Jpeg as copied from camera to lightroom](http://jthink.net/jaikoz/scratch/raw/jpeg.jpg)
[Raw as copied from camera to lightroom and immediately exported to jpeg](http://jthink.net/jaikoz/scratch/raw/raw.jpg)
[Raw as copied from camera to lightroom, tungsten whitebalance set and exported to jpg](http://jthink.net/jaikoz/scratch/raw/raw_after_tungsten.jpg) | 2014/05/24 | [
"https://photo.stackexchange.com/questions/50523",
"https://photo.stackexchange.com",
"https://photo.stackexchange.com/users/28237/"
] | It all boils down to different meanings for the word "tungsten".
Lightroom (or Adobe Camera Raw) is expecting "tungsten photographic lighting" when you select the Tungsten white balance preset. That means photofloods (type A or P bulbs with high wattage ratings - typically 250W or 500W - and a life expectancy of about 20 hours) or photography-oriented tungsten-halogen (quartz) lights, such as the Lowel Omni or Tota, a redhead or blonde, or a Fresnel spot such as the Arri 650. These all have colour temperatures of 3200K, which is really quite hot (blue) compared to household lighting or utility work lights, but it is the colour of light that tungsten (type B) film, both for stills and cine, are designed to work with. ("Tungsten" LEDs designed for photography are also 3200K.) In order to use the Tungsten preset (or type B tungsten film), you would need to use an 82-series blue cooling filter (either 82B or 82C) on the camera to raise the apparent colour temperature of the lighting from the typical very low household lighting range (2800K-2900K) to 3200K - otherwise your photographs are going to come out quite yellow.
The "Tungsten" white balance setting on your camera is a different beast altogether. For one thing, a consumer camera is not going to start with the assumption that you are shooting under Certified Official Photographic Lighting. But there's more to it than that. Unless you are using a custom white balance, the white balance setting on your digital camera (assuming it's not positively ancient and not a cheap toy) is not an absolute setting; it's more of an "automatic white balance with constraints" sort of thing. You'll find that, brightness of the scene aside, you'll get more or less the same picture using the camera's Tungsten setting under 2900K household lighting, 3200K photo/cine lighting or household/utility halogen lighting, which is somewhere in the middle. (It's only when you mix the types that you'll have problems.) The camera will record not only the setting you selected, but the colour temperature (yellow/blue) and tint (green/magenta) it selected under that setting into the file.
It is those recorded numbers that Lightroom/ACR will use as the "As Shot" values. (With allowances for differences between Adobe's idea of a "pleasing rendition" and the camera maker's.) When you select the Tungsten preset in Lightroom, you are effectively saying "forget what the camera thinks, I was shooting under 3200K lighting". In this case, that's a bit of a whopper; you're off by *at least* 32 [mireds](http://en.wikipedia.org/wiki/Mired), about the value given by an 82B cooling filter, and probably more.
If you want to get close to what the camera would have given you by itself, you can use "As Shot" *plus* setting the camera profile to the appropriate choice (such as "Camera Vivid") rather than leaving the default Adobe camera profile in place. It won't be exact, since it's Adobe's interpretation of the camera maker's "secret sauce", but it's usually pretty close. Or you can use the eydropper and the sliders to make the picture look the way you want it to. | tl;dr : no. You do not need anything more than lightroom (in terms of software to process the file)
Transforming from a raw file (that is the pure sensor readings per pixel) to something that you are displaying on a monitor is a rather complex process that involves a lot of math, quite some information additionally to the sensor readings, a pinch of secret sauce, and the turning of a lot of knobs that are up to whoever does the development process.
(note that I am mostly playing with dng files, and some details may be different in vendor specific raw files, but ultimately the underlying principles are the same).
Leaving details such as demosaicing out, the main part of "raw development" is doing the math to transform from the sensors colorspace (like xy), to the target rgb one (like sRGB or AdobeRGB). Here we have generally two approaches:
A matrix (or two). Those transform the whole 3d colorspace into another by shifting, rotating, tilting etc. it. This has some drawbacks: A lot of transformations here are linear, but the sensor responses are not. Additionally the matrix is valid for a specific lighting only (often D55 or D65) and in case of different lighting, sometimes an interpolation (or even extrapolation) of the matrix calculations is done to attribute for different lighting.
A profile table. To account for the nonlinearity of some sensor reponses, there exist calibration profiles. You can find them in lightroom, somewhere in the lower parts of all the knobs. These are mostly large tables that were calculated from special image targets photographed under special light conditions. Also here you sometimes have dual profiles that allow for inter/extrapolation, which contain the data of the same target under different lighting conditions.
The dng format saves these matrices for the raw converter, along with white balance information that helps in applying the matrices. Depending on the camera, this information contains some actual sensor readings, or is just some user setting. In most raw development programs, this will just preset the white balance adjustment sliders! The aforementioned calibration tables are usually part of the raw developer, if present at all.
So how does this process relate to the one your camera creates jpegs with? Most likely not at all. E.g. my canon ixus 950is has a built in table that it uses to calculate the jpeg image, in a way quite different to what adobe lightroom does.
Perception of a good white balance is very subjective and depends on many things, even such as the color of your monitors framing. So you don't like what came out of your tungsten setting? Adjust the knobs until you find the image nice, and resemble what you saw at the point you took it. That is about all what counts. You don't want a graphical representation of sensor values, you want to capture and reproduce a moment, and tell people what *you* saw at that point. Call it artistic freedom if you want.
But of course starting of with something that is a quite accurate sensor reading won't hurt, so how can be best achieve that? Generally for P&S cameras I found it good to work with the "as shot" white balance setting. In your case, your camera and Lightroom probably just have a rather different meaning of what "Tungsten" actually means.
For best results, you might want to invest a bit in a [color checker passport](http://www.luminous-landscape.com/reviews/accessories/colorchecker-psssport.shtml) or similar thing to be able to create profiles yourself, tailored to the specific lighting condition you encountered. It can also help finding a proper white point. Just use the included gray card part, and tell lightroom this is neutral color. This can often lead to quick satisfactory results.
And also note that it is called "raw development" (and not conversion) for a reason: you need to give input and tell the process how you would like the photo to look like. Play with the knobs. |
50,523 | I have a Canon Powershot S100 and use Adobe Photoshop 5.1, up until this point I have just saved images on my camera jpeg but I decided to try saving as raw format as well. So I set my camera to save as raw and jpeg, and in Lightroom I selected Preferences:General:Treat JPEG files as separate photos so I could compare the jpeg with the raw version.
Because it was evening and I was at home I took a photo in my lounge and set the white-balance to Tungsten.
Now as I understand RAW format ignore certain options set on the camera such as white balance and has to be applied in post-processing so I was expecting to see two photos that were similar but different, and that the most obvious difference would be white balance. In Lightroom the colours were indeed different so I set white balance of the RAW file to Tungsten and instead of that changing the colours so they were similar it made the picture very yellow and it **looked hideous.**
Am I doing something wrong or is this a problem with the camera or Lightrooom. DO I need to process the files with something else before using them with Lightroom ?
\*\* Edited \*\*
Here are the files:
[Jpeg as copied from camera to lightroom](http://jthink.net/jaikoz/scratch/raw/jpeg.jpg)
[Raw as copied from camera to lightroom and immediately exported to jpeg](http://jthink.net/jaikoz/scratch/raw/raw.jpg)
[Raw as copied from camera to lightroom, tungsten whitebalance set and exported to jpg](http://jthink.net/jaikoz/scratch/raw/raw_after_tungsten.jpg) | 2014/05/24 | [
"https://photo.stackexchange.com/questions/50523",
"https://photo.stackexchange.com",
"https://photo.stackexchange.com/users/28237/"
] | I think your overthinking things. Every RAW file is TAGGED with a white balance value. The tag simply contains the Kelvin rating for the white balance. If you selected Tungsten in camera, then by default the image, when rendered with Lightroom, will be rendered with a Kelvin rating somewhere between 2800K and 3300K (depends on the camera.)
If you further changed your white balance bu selecting Tungsten from "As Shot", then yes, your white balance is going to be incorrect. Even the seemingly minor change from 3300K to 2800K is actually huge. One has a soft yellow-orange appearance (3300K), and the other has a deep orange appearance (2800K), and that's just relative to each other.
So, effectively, yes you are "double applying" a Tungsten white balance, since Lightroom is already applying whatever Kelvin rating was stored in the RAW metadata. If you like how the image WB is when left at "As Shot", then just leave it at "As Shot". If you want it to be more orange, choose "Tungsten". If you want it to be whiter, choose "Daylight". Pretty much as simple as that. | tl;dr : no. You do not need anything more than lightroom (in terms of software to process the file)
Transforming from a raw file (that is the pure sensor readings per pixel) to something that you are displaying on a monitor is a rather complex process that involves a lot of math, quite some information additionally to the sensor readings, a pinch of secret sauce, and the turning of a lot of knobs that are up to whoever does the development process.
(note that I am mostly playing with dng files, and some details may be different in vendor specific raw files, but ultimately the underlying principles are the same).
Leaving details such as demosaicing out, the main part of "raw development" is doing the math to transform from the sensors colorspace (like xy), to the target rgb one (like sRGB or AdobeRGB). Here we have generally two approaches:
A matrix (or two). Those transform the whole 3d colorspace into another by shifting, rotating, tilting etc. it. This has some drawbacks: A lot of transformations here are linear, but the sensor responses are not. Additionally the matrix is valid for a specific lighting only (often D55 or D65) and in case of different lighting, sometimes an interpolation (or even extrapolation) of the matrix calculations is done to attribute for different lighting.
A profile table. To account for the nonlinearity of some sensor reponses, there exist calibration profiles. You can find them in lightroom, somewhere in the lower parts of all the knobs. These are mostly large tables that were calculated from special image targets photographed under special light conditions. Also here you sometimes have dual profiles that allow for inter/extrapolation, which contain the data of the same target under different lighting conditions.
The dng format saves these matrices for the raw converter, along with white balance information that helps in applying the matrices. Depending on the camera, this information contains some actual sensor readings, or is just some user setting. In most raw development programs, this will just preset the white balance adjustment sliders! The aforementioned calibration tables are usually part of the raw developer, if present at all.
So how does this process relate to the one your camera creates jpegs with? Most likely not at all. E.g. my canon ixus 950is has a built in table that it uses to calculate the jpeg image, in a way quite different to what adobe lightroom does.
Perception of a good white balance is very subjective and depends on many things, even such as the color of your monitors framing. So you don't like what came out of your tungsten setting? Adjust the knobs until you find the image nice, and resemble what you saw at the point you took it. That is about all what counts. You don't want a graphical representation of sensor values, you want to capture and reproduce a moment, and tell people what *you* saw at that point. Call it artistic freedom if you want.
But of course starting of with something that is a quite accurate sensor reading won't hurt, so how can be best achieve that? Generally for P&S cameras I found it good to work with the "as shot" white balance setting. In your case, your camera and Lightroom probably just have a rather different meaning of what "Tungsten" actually means.
For best results, you might want to invest a bit in a [color checker passport](http://www.luminous-landscape.com/reviews/accessories/colorchecker-psssport.shtml) or similar thing to be able to create profiles yourself, tailored to the specific lighting condition you encountered. It can also help finding a proper white point. Just use the included gray card part, and tell lightroom this is neutral color. This can often lead to quick satisfactory results.
And also note that it is called "raw development" (and not conversion) for a reason: you need to give input and tell the process how you would like the photo to look like. Play with the knobs. |
50,523 | I have a Canon Powershot S100 and use Adobe Photoshop 5.1, up until this point I have just saved images on my camera jpeg but I decided to try saving as raw format as well. So I set my camera to save as raw and jpeg, and in Lightroom I selected Preferences:General:Treat JPEG files as separate photos so I could compare the jpeg with the raw version.
Because it was evening and I was at home I took a photo in my lounge and set the white-balance to Tungsten.
Now as I understand RAW format ignore certain options set on the camera such as white balance and has to be applied in post-processing so I was expecting to see two photos that were similar but different, and that the most obvious difference would be white balance. In Lightroom the colours were indeed different so I set white balance of the RAW file to Tungsten and instead of that changing the colours so they were similar it made the picture very yellow and it **looked hideous.**
Am I doing something wrong or is this a problem with the camera or Lightrooom. DO I need to process the files with something else before using them with Lightroom ?
\*\* Edited \*\*
Here are the files:
[Jpeg as copied from camera to lightroom](http://jthink.net/jaikoz/scratch/raw/jpeg.jpg)
[Raw as copied from camera to lightroom and immediately exported to jpeg](http://jthink.net/jaikoz/scratch/raw/raw.jpg)
[Raw as copied from camera to lightroom, tungsten whitebalance set and exported to jpg](http://jthink.net/jaikoz/scratch/raw/raw_after_tungsten.jpg) | 2014/05/24 | [
"https://photo.stackexchange.com/questions/50523",
"https://photo.stackexchange.com",
"https://photo.stackexchange.com/users/28237/"
] | I think your overthinking things. Every RAW file is TAGGED with a white balance value. The tag simply contains the Kelvin rating for the white balance. If you selected Tungsten in camera, then by default the image, when rendered with Lightroom, will be rendered with a Kelvin rating somewhere between 2800K and 3300K (depends on the camera.)
If you further changed your white balance bu selecting Tungsten from "As Shot", then yes, your white balance is going to be incorrect. Even the seemingly minor change from 3300K to 2800K is actually huge. One has a soft yellow-orange appearance (3300K), and the other has a deep orange appearance (2800K), and that's just relative to each other.
So, effectively, yes you are "double applying" a Tungsten white balance, since Lightroom is already applying whatever Kelvin rating was stored in the RAW metadata. If you like how the image WB is when left at "As Shot", then just leave it at "As Shot". If you want it to be more orange, choose "Tungsten". If you want it to be whiter, choose "Daylight". Pretty much as simple as that. | It all boils down to different meanings for the word "tungsten".
Lightroom (or Adobe Camera Raw) is expecting "tungsten photographic lighting" when you select the Tungsten white balance preset. That means photofloods (type A or P bulbs with high wattage ratings - typically 250W or 500W - and a life expectancy of about 20 hours) or photography-oriented tungsten-halogen (quartz) lights, such as the Lowel Omni or Tota, a redhead or blonde, or a Fresnel spot such as the Arri 650. These all have colour temperatures of 3200K, which is really quite hot (blue) compared to household lighting or utility work lights, but it is the colour of light that tungsten (type B) film, both for stills and cine, are designed to work with. ("Tungsten" LEDs designed for photography are also 3200K.) In order to use the Tungsten preset (or type B tungsten film), you would need to use an 82-series blue cooling filter (either 82B or 82C) on the camera to raise the apparent colour temperature of the lighting from the typical very low household lighting range (2800K-2900K) to 3200K - otherwise your photographs are going to come out quite yellow.
The "Tungsten" white balance setting on your camera is a different beast altogether. For one thing, a consumer camera is not going to start with the assumption that you are shooting under Certified Official Photographic Lighting. But there's more to it than that. Unless you are using a custom white balance, the white balance setting on your digital camera (assuming it's not positively ancient and not a cheap toy) is not an absolute setting; it's more of an "automatic white balance with constraints" sort of thing. You'll find that, brightness of the scene aside, you'll get more or less the same picture using the camera's Tungsten setting under 2900K household lighting, 3200K photo/cine lighting or household/utility halogen lighting, which is somewhere in the middle. (It's only when you mix the types that you'll have problems.) The camera will record not only the setting you selected, but the colour temperature (yellow/blue) and tint (green/magenta) it selected under that setting into the file.
It is those recorded numbers that Lightroom/ACR will use as the "As Shot" values. (With allowances for differences between Adobe's idea of a "pleasing rendition" and the camera maker's.) When you select the Tungsten preset in Lightroom, you are effectively saying "forget what the camera thinks, I was shooting under 3200K lighting". In this case, that's a bit of a whopper; you're off by *at least* 32 [mireds](http://en.wikipedia.org/wiki/Mired), about the value given by an 82B cooling filter, and probably more.
If you want to get close to what the camera would have given you by itself, you can use "As Shot" *plus* setting the camera profile to the appropriate choice (such as "Camera Vivid") rather than leaving the default Adobe camera profile in place. It won't be exact, since it's Adobe's interpretation of the camera maker's "secret sauce", but it's usually pretty close. Or you can use the eydropper and the sliders to make the picture look the way you want it to. |
196,887 | I'm considering taking the Fearsome Rune on a weapon, and have feats or other runes which impose a saving throw on a hit/crit. Does the fear effect get applied before the saving throw, or after?
That is to say, will the fear penalty to checks apply to all these saves I might impose on a crit?
[Fearsome rune](https://2e.aonprd.com/Equipment.aspx?ID=731):
>
> When you critically hit with this weapon, the target becomes frightened 1.
>
>
>
[Frost rune](https://2e.aonprd.com/Equipment.aspx?ID=296):
>
> This weapon is empowered with freezing ice. It deals an additional 1d6 cold damage on a successful Strike. On a critical hit, the target is also slowed 1 until the end of your next turn unless it succeeds at a DC 24 Fortitude save.
>
>
>
[Stunning Fist](https://2e.aonprd.com/Feats.aspx?ID=442):
>
> The focused power of your flurry threatens to overwhelm your opponent. When you target the same creature with two Strikes from your Flurry of Blows, you can try to stun the creature. If either Strike hits and deals damage, the target must succeed at a Fortitude save against your class DC or be stunned 1 (or stunned 3 on a critical failure). This is an incapacitation effect.
>
>
>
[Brawling Crit specialisation](https://2e.aonprd.com/WeaponGroups.aspx?ID=4):
>
> The target must succeed at a Fortitude save against your class DC or be slowed 1 until the end of your next turn.
>
>
> | 2022/03/17 | [
"https://rpg.stackexchange.com/questions/196887",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/23134/"
] | It's unclear
============
I couldn't remember seeing a ruling on this, and that's no surprise as there is nothing in the [Encounter Mode](https://2e.aonprd.com/Rules.aspx?ID=429), [Playing the Game: Encounters](https://2e.aonprd.com/Rules.aspx?ID=13), [Turns](https://2e.aonprd.com/Rules.aspx?ID=435), nor [Actions](https://2e.aonprd.com/Rules.aspx?ID=387) rules about simultaneous *[Effects](https://2e.aonprd.com/Rules.aspx?ID=350)*. This issue reaches at least as far back as Pathfinder 1e's predecessor, D&D 3.5e.
There are generally two methods for resolving this
--------------------------------------------------
* All effects that can occur simultaneously do so without affecting each other
+ Result: The target is not Frightened until after making the Saves, at which point all incurred Conditions are applied
+ This is, in my experience, the most common [table ruling for Pathfinder 1e](https://rpg.stackexchange.com/a/50955/28326)
* The current turn holder decides the actual order of effects
+ Result: On your turn, you choose to apply the Frightened Condition, then the order of other effects the target must Save against; if you critically hit an Attack of Opportunity (or similar), the target creature chooses to make all appropriate Saves before becoming Frightened
+ This has been [codified as the official way to play D&D 5e](https://rpg.stackexchange.com/a/116463/28326) (it's up to your group(s) if this matters)
---
Addendum:
I did miss one option, which I have seen used but haven't come across a lot of formal community support for:
* The owner of the abilities chooses the order of effect.
+ Result: the Frightened effect happens before the Will Save
- has the benefit of being simple
- however, *all* simultaneous effects will be resolved in the most punishing way possible
---
Ask your GM which they use, or request which ruling that you consider to be more fun play. | They’re Frightened When They Make the Save
==========================================
As I've more deeply gone into with this [answer](https://rpg.stackexchange.com/a/199857/72765), each effect here happens at the same time. There's no mention in the rules about ordering these effects, so they all happen at the final step of resolving the [check](https://2e.aonprd.com/Rules.aspx?ID=314) for the attack.
>
> Pathfinder has many types of checks, from skill checks to attack rolls to saving throws, but they all follow these basic steps.
>
>
> * Roll a d20 and identify the modifiers, bonuses, and penalties that apply.
> * Calculate the result.
> * Compare the result to the difficulty class (DC).
> * **Determine the degree of success and the effect.**
>
>
>
In this case when you critically hit with your *fearsome frost weapon* using Flurry of Blows and with something that gives you the brawling critical specialization effect, the effect is:
* You hit and deal double damage (described under the rules for [damage](https://2e.aonprd.com/Rules.aspx?ID=335))
>
> In the midst of combat, you attempt checks to determine if you can damage your foe with weapons, spells, or alchemical concoctions. **On a successful check, you hit and deal damage.**
>
>
>
* The target becomes frightened 1
* The target is slowed 1 until the end of your next turn unless it succeeds at a DC 24 Fortitude save.
* The target must succeed at a Fortitude save against your class DC or be stunned 1 (or stunned 3 on a critical failure)
* The target must succeed at a Fortitude save against your class DC or be slowed 1 until the end of your next turn.
As each of these effects happen at the same time, **the creature is frightened when they are hit by the weapon** and that penalty would apply to each of the simultaneously applied saves. The saves aren't made before or after the attack hits, but are rather made *exactly* when the attack hits and the creature becomes frightened.
Where Things Would be Different
-------------------------------
Of note, this would be substantially different if the *fearsome* rune's effect gave a save to resist it.
As described above in the steps for handling checks, the effect of making that saving throw check would happen **after** rolling a d20 and identifying modifiers to the roll. With each rune's save happening at the same time this means the resulting effect(s) would happen after making those other checks—that they would only be frightened **after** having made those saves. |
190,455 | In the episode "The Red Forest," we deal extensively with a timeline where Cassie dies in 2015. In fact, this timeline's existence is crucial in providing Cole with important information about Operation Troy.
Now, in the season 4 episode "One Minute More" we've learned that
>
> Hannah Jones is Cole's mother.
>
>
>
However, in the timeline we see in the "The Red Forest"
* Jones was still committed to working on time travel at Raritan in 2043. We know her motivation for this was to save Hannah, so Hannah must've died in this timeline.
* Ramse still knew Cole, but he had already died in this timeline.
So with both Cassie and Cole dead, and Jones knowing neither of them, it's clear that the events of the season 2 episode "Lullaby" could never transpire in this timeline, so...
**How did Cole still exist in that particular timeline?** | 2018/07/01 | [
"https://scifi.stackexchange.com/questions/190455",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/57672/"
] | Terry has answered this officially on Twitter.
Tara O'Shea asked him:
>
> Ever have that thing where you're going crazy trying to understand how the dead Cole in the alternative future shown in #12Monkeys s1 "The Red Forest" could exist if in that timeline, Cole and Cassie never went back in time to save Cole's own mother as a child, or is it just me?
>
> [@tara\_oshea, 3 Jul 2018](https://twitter.com/tara_oshea/status/1014298979419508736)
>
>
>
The supposed official answer being:
>
> Because there was a Cole existing to undo the death. As long as there is a Cole, the Djinn, the serpent eats its tail. It’s a loop within a loop.
>
> [@TerryMatalas, 3 Jul 2018](https://twitter.com/TerryMatalas/status/1014318471910264834)
>
>
>
As unsatisfying as that is, it's as official as it gets... | You’re right, it doesn’t make sense. That “Red Forest” episode is in my view the show’s biggest plot hole. Just think through all the consequences of Cassie dying in 2015:
1. No Athan Cole
2. No Olivia embracing her destiny in the 1970’s
3. No Army of the 12 Monkeys
4. No funding of Project Splinter
And many other things. (I think the virus probably wouldn’t have been released, but that requires more thought.) Clearly if you wanted to actually depict what a future without Cassie would really look like, it would look very different than that episode.
I think the only “explanation” of that episode is that it demonstrates how little the creators had planned out the timeline of the show in advance. They didn’t all foresee all the consequential impacts the protagonists would have on the timeline of the show. Quite literally all they foresaw was the very next episode, where Cassie plays a role in preventing the release of the virus in Operation Troy. So they reasoned that without Cassie, the virus would have been released in Operation Troy. |
309,049 | I have a question regarding "The Road" by Cormac McCarthy. The book is written in past tense and uses past perfect form to tell us of what had happened before, but in this sentence Cormac uses present perfect instead:
>
> "In the produce section in the bottom of the bins they found a few ancient runner beans **and what looked to have once been apricots**, long dried to wrinkled effigies of themselves."
>
>
>
My question is why Cormac haven't written:
>
> ...and what looked to had once been apricots...
>
>
>
Is this a case of unwritten modal, as if: "and what looked to *must/could* have once been apricots"
---
Also in a spirit of the question above, how would native speaker react to such construction:
>
> "They partied all night, loads of alcohol, not less drugs and sexual levity. The party has been sublime."
>
>
>
What if a whole chapter before this fragment had been only using past simple and past perfect, and then it tacked on this present perfect sentence; does it change the narrator from an observer to an active participant? | 2016/02/22 | [
"https://english.stackexchange.com/questions/309049",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/-1/"
] | "Good" has many meanings, depending both on what kind of thing it is being applied to, and the context (eg, the purpose).
Some possible answers are 'quality', 'virtue', 'skill'. 'kindness', 'appropriateness'. I'm sure there are plenty more. | Technically, you can use "goodness" in that blank. However, if you define it that way, it's a bit of a circular definition ("good" would describe "goodness", hence "good" would describe "the quality of being good").
Perhaps "good describes the benevolence of someone" or "good is the quality of intending to leave a positive impact upon others" would be better? |
80,076 | I know Joel says that rewrites are always bad, m'kay, but that is assuming the person who wrote the code in the first place had some idea what they were doing.
I've got a medium sized (for a single developer anyway, ~18k LoC) C++ project, which I started when I did not truly know C++. Therefore, there are several things that are just... wrong. Wrong is the only way to describe it. It needs to be rewritten, plain and simple.
However -- I've spent a long freaking time doing the rewrite -- bugs in the original aren't getting fixed. However, some of the bugs themselves are problems with the architecture of the original tool -- and some of that is what I need to fix would require touching almost every line of code anyway.
On one hand, I feel fixing the bugs in the old program is going to be a massive wasted effort, because those bugs aren't even possible with the new design I've been working on. On the other hand, I've felt that I've neglected users of my original program because it's not been updated in so long.
What should I do? | 2011/05/29 | [
"https://softwareengineering.stackexchange.com/questions/80076",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/886/"
] | Two things:
1. It is said that only 20% of all features in a system is actually used, so if you want to shorten the rewrite time, consider working only on those 20% and release when they are done. Work incrementally.
2. You should use your knowledge of the old system and make the new system better, more focused and user friendly. Simply mimicking the old system piece by piece doesn't really give your users anything valuable. | This is a bit of a cop out answer, but if you find yourself getting too conflicted, that can in itself be your worst enemy. I think there's merit in both points of view. Search your feelings on it and commit to it, and follow through. In the end, it'll be about whether you completed or not. I doubt anyone will persecute you if you deliver. |
80,076 | I know Joel says that rewrites are always bad, m'kay, but that is assuming the person who wrote the code in the first place had some idea what they were doing.
I've got a medium sized (for a single developer anyway, ~18k LoC) C++ project, which I started when I did not truly know C++. Therefore, there are several things that are just... wrong. Wrong is the only way to describe it. It needs to be rewritten, plain and simple.
However -- I've spent a long freaking time doing the rewrite -- bugs in the original aren't getting fixed. However, some of the bugs themselves are problems with the architecture of the original tool -- and some of that is what I need to fix would require touching almost every line of code anyway.
On one hand, I feel fixing the bugs in the old program is going to be a massive wasted effort, because those bugs aren't even possible with the new design I've been working on. On the other hand, I've felt that I've neglected users of my original program because it's not been updated in so long.
What should I do? | 2011/05/29 | [
"https://softwareengineering.stackexchange.com/questions/80076",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/886/"
] | It sounds like you are suffering from [Second System Effect](http://c2.com/cgi/wiki?SecondSystemEffect).
I would suggest going back to the old system. Then choose between refactoring (which I'm not as big a fan of as many around here) or trying to write a minimal usable replacement for as little of the functionality of the original system as possible. But stay well away from, "Here is my grand design for how to do everything right!" Because that way there are dragons that have burned many unwary developers. | This is a bit of a cop out answer, but if you find yourself getting too conflicted, that can in itself be your worst enemy. I think there's merit in both points of view. Search your feelings on it and commit to it, and follow through. In the end, it'll be about whether you completed or not. I doubt anyone will persecute you if you deliver. |
80,076 | I know Joel says that rewrites are always bad, m'kay, but that is assuming the person who wrote the code in the first place had some idea what they were doing.
I've got a medium sized (for a single developer anyway, ~18k LoC) C++ project, which I started when I did not truly know C++. Therefore, there are several things that are just... wrong. Wrong is the only way to describe it. It needs to be rewritten, plain and simple.
However -- I've spent a long freaking time doing the rewrite -- bugs in the original aren't getting fixed. However, some of the bugs themselves are problems with the architecture of the original tool -- and some of that is what I need to fix would require touching almost every line of code anyway.
On one hand, I feel fixing the bugs in the old program is going to be a massive wasted effort, because those bugs aren't even possible with the new design I've been working on. On the other hand, I've felt that I've neglected users of my original program because it's not been updated in so long.
What should I do? | 2011/05/29 | [
"https://softwareengineering.stackexchange.com/questions/80076",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/886/"
] | Two things:
1. It is said that only 20% of all features in a system is actually used, so if you want to shorten the rewrite time, consider working only on those 20% and release when they are done. Work incrementally.
2. You should use your knowledge of the old system and make the new system better, more focused and user friendly. Simply mimicking the old system piece by piece doesn't really give your users anything valuable. | In my experience, when you have a project that is quite simply wrong from the bottom up, the best thing to do is set fire to it all and run around in your underwear for a bit, before sitting down and not just doing a rewrite, but a complete, bottom-up, clean-room rewrite of the entire project.
Some projects can be refactored into submission, sure, but some, …
Not so much.
Especially in old projects; starting out with a clean slate using modern tools is usually faster and less error-prone than trying to do a line-by-line rewrite; at least in my experience. |
80,076 | I know Joel says that rewrites are always bad, m'kay, but that is assuming the person who wrote the code in the first place had some idea what they were doing.
I've got a medium sized (for a single developer anyway, ~18k LoC) C++ project, which I started when I did not truly know C++. Therefore, there are several things that are just... wrong. Wrong is the only way to describe it. It needs to be rewritten, plain and simple.
However -- I've spent a long freaking time doing the rewrite -- bugs in the original aren't getting fixed. However, some of the bugs themselves are problems with the architecture of the original tool -- and some of that is what I need to fix would require touching almost every line of code anyway.
On one hand, I feel fixing the bugs in the old program is going to be a massive wasted effort, because those bugs aren't even possible with the new design I've been working on. On the other hand, I've felt that I've neglected users of my original program because it's not been updated in so long.
What should I do? | 2011/05/29 | [
"https://softwareengineering.stackexchange.com/questions/80076",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/886/"
] | It sounds like you are suffering from [Second System Effect](http://c2.com/cgi/wiki?SecondSystemEffect).
I would suggest going back to the old system. Then choose between refactoring (which I'm not as big a fan of as many around here) or trying to write a minimal usable replacement for as little of the functionality of the original system as possible. But stay well away from, "Here is my grand design for how to do everything right!" Because that way there are dragons that have burned many unwary developers. | In my experience, when you have a project that is quite simply wrong from the bottom up, the best thing to do is set fire to it all and run around in your underwear for a bit, before sitting down and not just doing a rewrite, but a complete, bottom-up, clean-room rewrite of the entire project.
Some projects can be refactored into submission, sure, but some, …
Not so much.
Especially in old projects; starting out with a clean slate using modern tools is usually faster and less error-prone than trying to do a line-by-line rewrite; at least in my experience. |
80,076 | I know Joel says that rewrites are always bad, m'kay, but that is assuming the person who wrote the code in the first place had some idea what they were doing.
I've got a medium sized (for a single developer anyway, ~18k LoC) C++ project, which I started when I did not truly know C++. Therefore, there are several things that are just... wrong. Wrong is the only way to describe it. It needs to be rewritten, plain and simple.
However -- I've spent a long freaking time doing the rewrite -- bugs in the original aren't getting fixed. However, some of the bugs themselves are problems with the architecture of the original tool -- and some of that is what I need to fix would require touching almost every line of code anyway.
On one hand, I feel fixing the bugs in the old program is going to be a massive wasted effort, because those bugs aren't even possible with the new design I've been working on. On the other hand, I've felt that I've neglected users of my original program because it's not been updated in so long.
What should I do? | 2011/05/29 | [
"https://softwareengineering.stackexchange.com/questions/80076",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/886/"
] | It sounds like you are suffering from [Second System Effect](http://c2.com/cgi/wiki?SecondSystemEffect).
I would suggest going back to the old system. Then choose between refactoring (which I'm not as big a fan of as many around here) or trying to write a minimal usable replacement for as little of the functionality of the original system as possible. But stay well away from, "Here is my grand design for how to do everything right!" Because that way there are dragons that have burned many unwary developers. | Two things:
1. It is said that only 20% of all features in a system is actually used, so if you want to shorten the rewrite time, consider working only on those 20% and release when they are done. Work incrementally.
2. You should use your knowledge of the old system and make the new system better, more focused and user friendly. Simply mimicking the old system piece by piece doesn't really give your users anything valuable. |
529,998 | I was wondering what could be the effect and possible advantage/disadvantage of replacing the Virtual VMWare with physical servers on performance of a web application | 2009/02/09 | [
"https://Stackoverflow.com/questions/529998",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/21380/"
] | Unfortunately there's not nearly enough information to give any advice on this.
If you have one VMware ESX server on a high-end hardware box, converting it to a physical server will give you a minimal performance advantage.
But there are SO many variables here, your application could be going slower than it would on a physical machine for a number of VMware configuration reasons. Generally a properly configured VMware infrastructure in a production environment won't be much slower than the physical equivalent with the same allocated resources. | You need to look at where your performance is being hit - are you CPU, memory, drive, network bound? You need to understand what is slowing you down before you can even start to ask questions like this.
If you are CPU bound then can you move clients between you host boxes to even out load. If you are memory bound then can you increase the RAM assigned to the bound client. Drive bound - then you need to sort out your SAN throughput. If you are network bound then adding an additional network card to the host machine and adding an additional virtual network to spread the load can help. |
8,906 | Is there any combination of iPhone and/or Mac apps that I can use to send a push notification to my iPhone?
For example, let's say I want to create a service (invoked via (Application Name) > Services) which sends the highlighted text on my Mac to my iPhone as a push notification message. | 2011/02/22 | [
"https://apple.stackexchange.com/questions/8906",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/218/"
] | The free app [Boxcar](http://boxcar.io/) allows you to forward Growl notifications to your iPhone. You can also use their [API](http://boxcar.io/help/api/providers) to send custom push notifications from any app or script. I use it with Growl (never used their API, though) and it works great. | Depends on what you're looking for, but you could use [Find my iPhone](http://me.com/find). It's [free](http://lifehacker.com/#!5696311/how-to-enable-and-use-find-my-iphone-for-free-on-iphone-3gs-and-other-pre+2010-devices), native and [easy to install](http://www.apple.com/iphone/find-my-iphone-setup/) and it [features](http://www.apple.com/iphone/features/find-my-iphone.html) a "Display Message" that's pushed into the phone. |
8,906 | Is there any combination of iPhone and/or Mac apps that I can use to send a push notification to my iPhone?
For example, let's say I want to create a service (invoked via (Application Name) > Services) which sends the highlighted text on my Mac to my iPhone as a push notification message. | 2011/02/22 | [
"https://apple.stackexchange.com/questions/8906",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/218/"
] | I think a combination of [**Growl**](http://growl.info/) (OS X notifier) and [**Prowl**](http://www.prowlapp.com/) (an iPhone app that forwards Push Notifcations from Growl) with your AppleScript interacting with Growl directly would be the way to go for this. | The free app [Boxcar](http://boxcar.io/) allows you to forward Growl notifications to your iPhone. You can also use their [API](http://boxcar.io/help/api/providers) to send custom push notifications from any app or script. I use it with Growl (never used their API, though) and it works great. |
8,906 | Is there any combination of iPhone and/or Mac apps that I can use to send a push notification to my iPhone?
For example, let's say I want to create a service (invoked via (Application Name) > Services) which sends the highlighted text on my Mac to my iPhone as a push notification message. | 2011/02/22 | [
"https://apple.stackexchange.com/questions/8906",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/218/"
] | The free app [Boxcar](http://boxcar.io/) allows you to forward Growl notifications to your iPhone. You can also use their [API](http://boxcar.io/help/api/providers) to send custom push notifications from any app or script. I use it with Growl (never used their API, though) and it works great. | There is a web service <http://pushme.to/> and ios app that could be implemented that would solve your problem although it doesn't appear to be in the app store at the moment pending some bug fixes i believe.
There are other apps that use an api to push messages to an ios device via a wordpress site oddly. <http://ipush.me/>
you should be able to create a native app using a website (you could create) that effectively is a form to send the details (name/message) to this service. |
1,288 | I am planning to build a device able to detect and tell a server via Wi-Fi if a chair is occupied. How would you do it? And how cheap do you think the device could be? | 2014/04/25 | [
"https://arduino.stackexchange.com/questions/1288",
"https://arduino.stackexchange.com",
"https://arduino.stackexchange.com/users/1178/"
] | For a soft seat you could sense occupancy with an LED and photo-sensor at opposite ends of a short somewhat flexible tube that gets flexed when the cushion compresses, interrupting the light. That or a microswitch would have to be the cheapest means of sensing.
Getting from there to the server depends a little on how much work you're willing to do, from rolling your own micro-controller+WiFi PCB to purchasing off the shelf parts, which may in turn, depend on whether you need to monitor one chair or a whole auditorium. | You could use [the awesome CapSense-Library](http://playground.arduino.cc/Main/CapacitiveSensor?from=Main.CapSense). Additionally to the Library you only need a thin piece of conducting material e.g. aluminium foil and two pins on your arduino. The only thing you have to do is experiment with different resistors to reliably distinguish between someone sitting on the chair or not. Advantages of this method are:
* virtually no costs at all
* easy to implement
* not subject to wear and tear
* should work with any kind of chair independent of material e.g.
hard or soft surface
* consumes next to no power (I assume the whole device runs on battery since it's attached to a movable chair)
* could even sense a person in the process of seating her-/himself and enable you to start the music faster (my stereo for example takes a second or so to start up) |
1,288 | I am planning to build a device able to detect and tell a server via Wi-Fi if a chair is occupied. How would you do it? And how cheap do you think the device could be? | 2014/04/25 | [
"https://arduino.stackexchange.com/questions/1288",
"https://arduino.stackexchange.com",
"https://arduino.stackexchange.com/users/1178/"
] | I'm not going to answer this directly, because then you wouldn't learn anything! However, here are a few suggestions:
* Use a pressure sensor on the seat of the chair or
* Put a distance sensor (IR or ultrasonic) pointing at the chair.
* Use the official [Arduino WiFi shield](http://arduino.cc/en/Main/ArduinoWiFiShield). | You could use [the awesome CapSense-Library](http://playground.arduino.cc/Main/CapacitiveSensor?from=Main.CapSense). Additionally to the Library you only need a thin piece of conducting material e.g. aluminium foil and two pins on your arduino. The only thing you have to do is experiment with different resistors to reliably distinguish between someone sitting on the chair or not. Advantages of this method are:
* virtually no costs at all
* easy to implement
* not subject to wear and tear
* should work with any kind of chair independent of material e.g.
hard or soft surface
* consumes next to no power (I assume the whole device runs on battery since it's attached to a movable chair)
* could even sense a person in the process of seating her-/himself and enable you to start the music faster (my stereo for example takes a second or so to start up) |
1,288 | I am planning to build a device able to detect and tell a server via Wi-Fi if a chair is occupied. How would you do it? And how cheap do you think the device could be? | 2014/04/25 | [
"https://arduino.stackexchange.com/questions/1288",
"https://arduino.stackexchange.com",
"https://arduino.stackexchange.com/users/1178/"
] | Oh wow, so many ways you could do this. To start, get an arduino with a wifi shield to transmit and read data. Familiarize yourself with how the arduino works with the shield, and how to read it on the other end. Then it's time to look at sensors you could use. Here's a couple ideas, I would recommend using more than one and cross-checking:
1. Force sensor on base of chair: Can tell you how much weight is on a chair (Sparkfun SEN-09376)
2. IR or sonic sensor on back of chair to detect distance ([example](https://www.sparkfun.com/products/242))
3. Vibration/shock sensor to detect if someone has sit down ([example](https://www.sparkfun.com/products/9197))
4. Load sensor: literally a scale in a sensor. (Sparkfun SEN-10245)
The optimal solution if you had the cash would be to put all of them on the chair and use the arduino to compute all of the sensor values into one boolean. However, if you only could have one sensor I would recommend the load sensor which would definitely be the most reliable of all the examples I gave. | You could use [the awesome CapSense-Library](http://playground.arduino.cc/Main/CapacitiveSensor?from=Main.CapSense). Additionally to the Library you only need a thin piece of conducting material e.g. aluminium foil and two pins on your arduino. The only thing you have to do is experiment with different resistors to reliably distinguish between someone sitting on the chair or not. Advantages of this method are:
* virtually no costs at all
* easy to implement
* not subject to wear and tear
* should work with any kind of chair independent of material e.g.
hard or soft surface
* consumes next to no power (I assume the whole device runs on battery since it's attached to a movable chair)
* could even sense a person in the process of seating her-/himself and enable you to start the music faster (my stereo for example takes a second or so to start up) |
1,288 | I am planning to build a device able to detect and tell a server via Wi-Fi if a chair is occupied. How would you do it? And how cheap do you think the device could be? | 2014/04/25 | [
"https://arduino.stackexchange.com/questions/1288",
"https://arduino.stackexchange.com",
"https://arduino.stackexchange.com/users/1178/"
] | You could use Electric Field Sensing, it allows you to detect the presence and position of conductive objects even if the sensor is covered by an opaque object. The technology is used in cars to detect if someone is sitting in a seat so the car can beep at you to put your seat-belt on. However, if all you want to do is detect presence then this is no better than using CapSense.
<http://web.media.mit.edu/~jrs/efs.html>
<https://en.wikipedia.org/wiki/Electric_field_proximity_sensing>
To communicate with a server over WiFi you could use the Arduino WiFi shield, the Arduino Yun (which has on-board WiFi) or buy a ethernet WiFi adapter and use it with an Arduino board which has ethernet.
<http://arduino.cc/en/Main/ArduinoWiFiShield>
<http://arduino.cc/en/Main/ArduinoBoardYun>
(Arduino board with on-board WiFi)
<http://arduino.cc/en/Main/ArduinoBoardEthernet> | conductive foam as sensor. it chg resistance when compressed.
or use image from camera to determine if seat is occupied. only one source for all data. |
1,288 | I am planning to build a device able to detect and tell a server via Wi-Fi if a chair is occupied. How would you do it? And how cheap do you think the device could be? | 2014/04/25 | [
"https://arduino.stackexchange.com/questions/1288",
"https://arduino.stackexchange.com",
"https://arduino.stackexchange.com/users/1178/"
] | Oh wow, so many ways you could do this. To start, get an arduino with a wifi shield to transmit and read data. Familiarize yourself with how the arduino works with the shield, and how to read it on the other end. Then it's time to look at sensors you could use. Here's a couple ideas, I would recommend using more than one and cross-checking:
1. Force sensor on base of chair: Can tell you how much weight is on a chair (Sparkfun SEN-09376)
2. IR or sonic sensor on back of chair to detect distance ([example](https://www.sparkfun.com/products/242))
3. Vibration/shock sensor to detect if someone has sit down ([example](https://www.sparkfun.com/products/9197))
4. Load sensor: literally a scale in a sensor. (Sparkfun SEN-10245)
The optimal solution if you had the cash would be to put all of them on the chair and use the arduino to compute all of the sensor values into one boolean. However, if you only could have one sensor I would recommend the load sensor which would definitely be the most reliable of all the examples I gave. | I'm not going to answer this directly, because then you wouldn't learn anything! However, here are a few suggestions:
* Use a pressure sensor on the seat of the chair or
* Put a distance sensor (IR or ultrasonic) pointing at the chair.
* Use the official [Arduino WiFi shield](http://arduino.cc/en/Main/ArduinoWiFiShield). |
1,288 | I am planning to build a device able to detect and tell a server via Wi-Fi if a chair is occupied. How would you do it? And how cheap do you think the device could be? | 2014/04/25 | [
"https://arduino.stackexchange.com/questions/1288",
"https://arduino.stackexchange.com",
"https://arduino.stackexchange.com/users/1178/"
] | You could use [the awesome CapSense-Library](http://playground.arduino.cc/Main/CapacitiveSensor?from=Main.CapSense). Additionally to the Library you only need a thin piece of conducting material e.g. aluminium foil and two pins on your arduino. The only thing you have to do is experiment with different resistors to reliably distinguish between someone sitting on the chair or not. Advantages of this method are:
* virtually no costs at all
* easy to implement
* not subject to wear and tear
* should work with any kind of chair independent of material e.g.
hard or soft surface
* consumes next to no power (I assume the whole device runs on battery since it's attached to a movable chair)
* could even sense a person in the process of seating her-/himself and enable you to start the music faster (my stereo for example takes a second or so to start up) | conductive foam as sensor. it chg resistance when compressed.
or use image from camera to determine if seat is occupied. only one source for all data. |
1,288 | I am planning to build a device able to detect and tell a server via Wi-Fi if a chair is occupied. How would you do it? And how cheap do you think the device could be? | 2014/04/25 | [
"https://arduino.stackexchange.com/questions/1288",
"https://arduino.stackexchange.com",
"https://arduino.stackexchange.com/users/1178/"
] | For a soft seat you could sense occupancy with an LED and photo-sensor at opposite ends of a short somewhat flexible tube that gets flexed when the cushion compresses, interrupting the light. That or a microswitch would have to be the cheapest means of sensing.
Getting from there to the server depends a little on how much work you're willing to do, from rolling your own micro-controller+WiFi PCB to purchasing off the shelf parts, which may in turn, depend on whether you need to monitor one chair or a whole auditorium. | conductive foam as sensor. it chg resistance when compressed.
or use image from camera to determine if seat is occupied. only one source for all data. |
1,288 | I am planning to build a device able to detect and tell a server via Wi-Fi if a chair is occupied. How would you do it? And how cheap do you think the device could be? | 2014/04/25 | [
"https://arduino.stackexchange.com/questions/1288",
"https://arduino.stackexchange.com",
"https://arduino.stackexchange.com/users/1178/"
] | I'm not going to answer this directly, because then you wouldn't learn anything! However, here are a few suggestions:
* Use a pressure sensor on the seat of the chair or
* Put a distance sensor (IR or ultrasonic) pointing at the chair.
* Use the official [Arduino WiFi shield](http://arduino.cc/en/Main/ArduinoWiFiShield). | You could use Electric Field Sensing, it allows you to detect the presence and position of conductive objects even if the sensor is covered by an opaque object. The technology is used in cars to detect if someone is sitting in a seat so the car can beep at you to put your seat-belt on. However, if all you want to do is detect presence then this is no better than using CapSense.
<http://web.media.mit.edu/~jrs/efs.html>
<https://en.wikipedia.org/wiki/Electric_field_proximity_sensing>
To communicate with a server over WiFi you could use the Arduino WiFi shield, the Arduino Yun (which has on-board WiFi) or buy a ethernet WiFi adapter and use it with an Arduino board which has ethernet.
<http://arduino.cc/en/Main/ArduinoWiFiShield>
<http://arduino.cc/en/Main/ArduinoBoardYun>
(Arduino board with on-board WiFi)
<http://arduino.cc/en/Main/ArduinoBoardEthernet> |
1,288 | I am planning to build a device able to detect and tell a server via Wi-Fi if a chair is occupied. How would you do it? And how cheap do you think the device could be? | 2014/04/25 | [
"https://arduino.stackexchange.com/questions/1288",
"https://arduino.stackexchange.com",
"https://arduino.stackexchange.com/users/1178/"
] | For a soft seat you could sense occupancy with an LED and photo-sensor at opposite ends of a short somewhat flexible tube that gets flexed when the cushion compresses, interrupting the light. That or a microswitch would have to be the cheapest means of sensing.
Getting from there to the server depends a little on how much work you're willing to do, from rolling your own micro-controller+WiFi PCB to purchasing off the shelf parts, which may in turn, depend on whether you need to monitor one chair or a whole auditorium. | You could use Electric Field Sensing, it allows you to detect the presence and position of conductive objects even if the sensor is covered by an opaque object. The technology is used in cars to detect if someone is sitting in a seat so the car can beep at you to put your seat-belt on. However, if all you want to do is detect presence then this is no better than using CapSense.
<http://web.media.mit.edu/~jrs/efs.html>
<https://en.wikipedia.org/wiki/Electric_field_proximity_sensing>
To communicate with a server over WiFi you could use the Arduino WiFi shield, the Arduino Yun (which has on-board WiFi) or buy a ethernet WiFi adapter and use it with an Arduino board which has ethernet.
<http://arduino.cc/en/Main/ArduinoWiFiShield>
<http://arduino.cc/en/Main/ArduinoBoardYun>
(Arduino board with on-board WiFi)
<http://arduino.cc/en/Main/ArduinoBoardEthernet> |
1,288 | I am planning to build a device able to detect and tell a server via Wi-Fi if a chair is occupied. How would you do it? And how cheap do you think the device could be? | 2014/04/25 | [
"https://arduino.stackexchange.com/questions/1288",
"https://arduino.stackexchange.com",
"https://arduino.stackexchange.com/users/1178/"
] | Oh wow, so many ways you could do this. To start, get an arduino with a wifi shield to transmit and read data. Familiarize yourself with how the arduino works with the shield, and how to read it on the other end. Then it's time to look at sensors you could use. Here's a couple ideas, I would recommend using more than one and cross-checking:
1. Force sensor on base of chair: Can tell you how much weight is on a chair (Sparkfun SEN-09376)
2. IR or sonic sensor on back of chair to detect distance ([example](https://www.sparkfun.com/products/242))
3. Vibration/shock sensor to detect if someone has sit down ([example](https://www.sparkfun.com/products/9197))
4. Load sensor: literally a scale in a sensor. (Sparkfun SEN-10245)
The optimal solution if you had the cash would be to put all of them on the chair and use the arduino to compute all of the sensor values into one boolean. However, if you only could have one sensor I would recommend the load sensor which would definitely be the most reliable of all the examples I gave. | conductive foam as sensor. it chg resistance when compressed.
or use image from camera to determine if seat is occupied. only one source for all data. |
2,687,099 | Can anyone tell me how to create a custom installer to 'install' games. I say custom meaning I don't want the user to have the option where the game is installed. I want it to be a straight forward process, maybe with just one loading bar.
The program I'm developing is a 'center' for game playing, which includes a community and other features, such as a timer that records how long a game is played for. I just thought that installing each game in one place, with a simple installer would make the program easier to use. It also will allow me to do other features as the games will all be installed in one place. No need for the user to specify where the game is installed.
Would this be possible? | 2010/04/21 | [
"https://Stackoverflow.com/questions/2687099",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/303221/"
] | I'm presuming your game is developed in C#, rather than requiring the installer be written in C#?
If that's the case, there are plenty of options available to you for installer packages. Probably the most customisable option, whilst still being free, is [Nullsoft Install System](http://nsis.sourceforge.net/Main_Page). The installers are built around some basic scripting activities, and can be as simple or complex as you desire - the installation, and the wiki have plenty of example scripts that you can explore and experiment with.
---
**OT: Install Location**
Personally, I'd consider it bad practice to disallow the user from selecting their own install location and, in fact, it gets me pretty frustrated when anything but system-file installations (e.g. drivers) stop me from choosing a directory. Many users will choose to locate certain types of installation and data on a non-default device (e.g. virtually all of my games are housed on a separate drive to my main Windows installation). If you need to remember the installation location so badly, create a registry key for it. | Another system you can use is called Inno Setup - <http://www.jrsoftware.org/isinfo.php> |
2,687,099 | Can anyone tell me how to create a custom installer to 'install' games. I say custom meaning I don't want the user to have the option where the game is installed. I want it to be a straight forward process, maybe with just one loading bar.
The program I'm developing is a 'center' for game playing, which includes a community and other features, such as a timer that records how long a game is played for. I just thought that installing each game in one place, with a simple installer would make the program easier to use. It also will allow me to do other features as the games will all be installed in one place. No need for the user to specify where the game is installed.
Would this be possible? | 2010/04/21 | [
"https://Stackoverflow.com/questions/2687099",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/303221/"
] | I'm presuming your game is developed in C#, rather than requiring the installer be written in C#?
If that's the case, there are plenty of options available to you for installer packages. Probably the most customisable option, whilst still being free, is [Nullsoft Install System](http://nsis.sourceforge.net/Main_Page). The installers are built around some basic scripting activities, and can be as simple or complex as you desire - the installation, and the wiki have plenty of example scripts that you can explore and experiment with.
---
**OT: Install Location**
Personally, I'd consider it bad practice to disallow the user from selecting their own install location and, in fact, it gets me pretty frustrated when anything but system-file installations (e.g. drivers) stop me from choosing a directory. Many users will choose to locate certain types of installation and data on a non-default device (e.g. virtually all of my games are housed on a separate drive to my main Windows installation). If you need to remember the installation location so badly, create a registry key for it. | If the games already exist your best option would be to call the MSI installers in administrative mode (see documentation for MSIExec). Then you could actually
* Set a predetermined location for the games
* Remove any UI and replace that with your custom installer UI
Obviously that would only work if the installs are really MSI modules (with some more work also for installers that have MSIs packed into EXE setups). That is true for most, but likely not all games.
Please note that this would be a sizable task and to be honest I cannot see any value in doing what you are planning. But thats up to you.
As start you would have to read into the MSI documentation. I'd recommend [WIX (Windows Installer XML)](http://wix.sourceforge.net/) for the beginning. |
2,687,099 | Can anyone tell me how to create a custom installer to 'install' games. I say custom meaning I don't want the user to have the option where the game is installed. I want it to be a straight forward process, maybe with just one loading bar.
The program I'm developing is a 'center' for game playing, which includes a community and other features, such as a timer that records how long a game is played for. I just thought that installing each game in one place, with a simple installer would make the program easier to use. It also will allow me to do other features as the games will all be installed in one place. No need for the user to specify where the game is installed.
Would this be possible? | 2010/04/21 | [
"https://Stackoverflow.com/questions/2687099",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/303221/"
] | Another system you can use is called Inno Setup - <http://www.jrsoftware.org/isinfo.php> | If the games already exist your best option would be to call the MSI installers in administrative mode (see documentation for MSIExec). Then you could actually
* Set a predetermined location for the games
* Remove any UI and replace that with your custom installer UI
Obviously that would only work if the installs are really MSI modules (with some more work also for installers that have MSIs packed into EXE setups). That is true for most, but likely not all games.
Please note that this would be a sizable task and to be honest I cannot see any value in doing what you are planning. But thats up to you.
As start you would have to read into the MSI documentation. I'd recommend [WIX (Windows Installer XML)](http://wix.sourceforge.net/) for the beginning. |
918 | I was at a party a few days ago with a doctor (the medical kind, not the research kind) who was thinking about writing a computer program to solve a scheduling problem at work. Someone introduced him to me because I have a CS degree and worked as a software engineer for a few years.
It wasn't long before we moved on from the specific problem he had (for which the answer was "hire a freelancer" or at least "I can't solve this for you just standing here with a beer and without a computer") to talking about computer science in general. To his credit, he asked good questions, picked up on the answers immediately, and asked smart follow-ups. But a lot of stuff that's second nature to us CS people was totally new and surprising to him.
The big one, which isn't surprising in hindsight but which we didn't get to until late in the conversation, was that computer science isn't the same as programming. There was also the fact that complexity/Big-O makes a real difference, and that the Halting Problem/unsolvability exists. It kinda made me feel like I wasn't a great ambassador for CS.
My actual question here is: how do you explain computer science to people when you have not a year or a semester, but just an hour, or even only five minutes?
*(This question might be a little outside the typical scope for this site, but it's still relatively early in the beta, so I figured let's give it a shot.)* | 2017/06/21 | [
"https://cseducators.stackexchange.com/questions/918",
"https://cseducators.stackexchange.com",
"https://cseducators.stackexchange.com/users/1166/"
] | I regularly have to explain what *computer science* is to parents, and I have lately settled into this explanation:
Technology keeps changing all the time. You get used to the menus in Microsoft Word, and then they change it to the Ribbon. You learn to program buttons in Java using Applets, and then Applets get removed from every major browser as a security risk.
But there are some things that *never* change, because they're in the realms of mathematics, or they are fundamental organizing principles. For instance, computer right now work in binary, 1s and 0s. The properties of binary numbers themselves aren't going to change no matter what new technology comes around tomorrow. We might create a computer that's not based on binary, but the properties of binary itself are fixed. This is the realm of computer science. Computer science is the foundational stuff that doesn't change.
It's highly mathematical, highly theoretical, and there are a lot of proofs involved, but when you study computer science, you are studying the deeper question in the nature of computation itself, and that's stuff that never gets dated. | I would explain it like this:
In reality, you have to solve problems on your daily basis. It may be a time problem, like "how do I get these five tasks done it just 1 hour?" or "how can I stack these boxes so that they all fit into the cupboard?".
Computer science is in many ways equal to solving these problems, only that the problems are of a little more mathematical and logical manner.
One rather common problem of computer science is "how do I sort a list of numbers?". When a person is given this task, he or she will most likely pick out the lowest or highest number first, put it onto the sorted list and continue from the start until no numbers remain in the unsorted list. This is one solution for the sorting problem, and computer scientists often have to solve this task too. As you can imagine, like described above, it will take a relatively long time to sort all the numbers, as you will repeatedly look at all numbers to sort out the lowest / highest one. So one person once thought "how could I solve this problem faster?" and maybe created an algorithm to solve the task for example twice as fast as the original approach.
Solving problems, not only using the most intuitive way which often tends to be very slow, but thinking about a more complex and strategical approach, to get a given task done as fast as possible, this is a major part of computer science. |
918 | I was at a party a few days ago with a doctor (the medical kind, not the research kind) who was thinking about writing a computer program to solve a scheduling problem at work. Someone introduced him to me because I have a CS degree and worked as a software engineer for a few years.
It wasn't long before we moved on from the specific problem he had (for which the answer was "hire a freelancer" or at least "I can't solve this for you just standing here with a beer and without a computer") to talking about computer science in general. To his credit, he asked good questions, picked up on the answers immediately, and asked smart follow-ups. But a lot of stuff that's second nature to us CS people was totally new and surprising to him.
The big one, which isn't surprising in hindsight but which we didn't get to until late in the conversation, was that computer science isn't the same as programming. There was also the fact that complexity/Big-O makes a real difference, and that the Halting Problem/unsolvability exists. It kinda made me feel like I wasn't a great ambassador for CS.
My actual question here is: how do you explain computer science to people when you have not a year or a semester, but just an hour, or even only five minutes?
*(This question might be a little outside the typical scope for this site, but it's still relatively early in the beta, so I figured let's give it a shot.)* | 2017/06/21 | [
"https://cseducators.stackexchange.com/questions/918",
"https://cseducators.stackexchange.com",
"https://cseducators.stackexchange.com/users/1166/"
] | I'll attempt a self-answer here, based on hindsight and a few previous experiences where I went in knowing I wanted to do this.
I've found that starting off with an analogy helps a lot of the time. Friends and co-workers have reported similar results in my super unscientific poll. The one we use is along the lines of
>
> Computer science has as much to do with programming as architecture has to do with bricklaying
>
>
>
or
>
> CS is to coding as astronomy is to telescopes
>
>
>
It can be helpful to try to make the analogy with the listener's own profession, as long as it doesn't backfire by derailing the conversation.
This then leads into
>
> Computer science is an academic field. It's theoretical. Programming is more practical; it's a tool.
>
>
>
In my story above, I segued from this into the Halting Problem and efficiency. Looking back, I think that was too big of a jump, at least when presented as abstract concepts. I like the phone book example mentioned in [Peter's answer](https://cseducators.stackexchange.com/a/932/1166). I think I'd modify it this way:
>
> One big part of computer science is "algorithms," which is a fancy word for "figuring out a good way to do things." A good example of this is finding someone's number in the phone book. You could just open the book to random places and hope you get lucky. You could start on page one and start reading straight through until you find the person you want. You could take advantage of the alphabetical sorting and index to see what page the people with similar names start on.
>
>
> Using the index is clearly smarter than repeatedly picking random pages. Coming up with these better ways to do things; that's computer science. The details get really complicated (and are a big part of the field) but it turns out that what seem like small differences in efficiency, or memory usage, or other factors like that, can make a **huge** difference how good an algorithm is in the real world.
>
>
> Now, once you have the plan, you might want to tell someone else how to do it. I could tell someone the exact same phone book search plan in English, or Spanish, or Hindi. I could tell a computer how to do it in C++, or Java, or Ruby. Programming is just a way of communicating instructions to a computer, the same way human languages are a way of communicating information to other people.
>
>
>
The downside of this answer is that it doesn't get into the mathematical foundation of CS, or how CS is about unchanging fundamental concepts. But I'm beginning to think that's not a big problem... such topics might be beyond the scope of a five-minute intro for a complete layperson. | I don't know if this will help you, but I often find myself in the position of explaining the difference between CS and IT to students / prospective students / parents, and I use the experience of being a one-time emergency medical technician to help.
I compare the difference between CS and IT to the difference between medical doctors and EMTs. As an EMT, I was required by law to follow the protocols established by physicians, who get to do the experimenting and the researching and the paper-writing. As an IT worker, you will be handed a set of tools (databases, operating systems, programming languages) and have to work with what the researchers (the Computer Scientists) come up with. The world needs IT workers as much as they need EMTs, so it isn't less, just different.
It's not perfect, but I teach at a two-year school, so it's enough to get students thinking about which major to choose. |
918 | I was at a party a few days ago with a doctor (the medical kind, not the research kind) who was thinking about writing a computer program to solve a scheduling problem at work. Someone introduced him to me because I have a CS degree and worked as a software engineer for a few years.
It wasn't long before we moved on from the specific problem he had (for which the answer was "hire a freelancer" or at least "I can't solve this for you just standing here with a beer and without a computer") to talking about computer science in general. To his credit, he asked good questions, picked up on the answers immediately, and asked smart follow-ups. But a lot of stuff that's second nature to us CS people was totally new and surprising to him.
The big one, which isn't surprising in hindsight but which we didn't get to until late in the conversation, was that computer science isn't the same as programming. There was also the fact that complexity/Big-O makes a real difference, and that the Halting Problem/unsolvability exists. It kinda made me feel like I wasn't a great ambassador for CS.
My actual question here is: how do you explain computer science to people when you have not a year or a semester, but just an hour, or even only five minutes?
*(This question might be a little outside the typical scope for this site, but it's still relatively early in the beta, so I figured let's give it a shot.)* | 2017/06/21 | [
"https://cseducators.stackexchange.com/questions/918",
"https://cseducators.stackexchange.com",
"https://cseducators.stackexchange.com/users/1166/"
] | I regularly have to explain what *computer science* is to parents, and I have lately settled into this explanation:
Technology keeps changing all the time. You get used to the menus in Microsoft Word, and then they change it to the Ribbon. You learn to program buttons in Java using Applets, and then Applets get removed from every major browser as a security risk.
But there are some things that *never* change, because they're in the realms of mathematics, or they are fundamental organizing principles. For instance, computer right now work in binary, 1s and 0s. The properties of binary numbers themselves aren't going to change no matter what new technology comes around tomorrow. We might create a computer that's not based on binary, but the properties of binary itself are fixed. This is the realm of computer science. Computer science is the foundational stuff that doesn't change.
It's highly mathematical, highly theoretical, and there are a lot of proofs involved, but when you study computer science, you are studying the deeper question in the nature of computation itself, and that's stuff that never gets dated. | I don't know if this will help you, but I often find myself in the position of explaining the difference between CS and IT to students / prospective students / parents, and I use the experience of being a one-time emergency medical technician to help.
I compare the difference between CS and IT to the difference between medical doctors and EMTs. As an EMT, I was required by law to follow the protocols established by physicians, who get to do the experimenting and the researching and the paper-writing. As an IT worker, you will be handed a set of tools (databases, operating systems, programming languages) and have to work with what the researchers (the Computer Scientists) come up with. The world needs IT workers as much as they need EMTs, so it isn't less, just different.
It's not perfect, but I teach at a two-year school, so it's enough to get students thinking about which major to choose. |
918 | I was at a party a few days ago with a doctor (the medical kind, not the research kind) who was thinking about writing a computer program to solve a scheduling problem at work. Someone introduced him to me because I have a CS degree and worked as a software engineer for a few years.
It wasn't long before we moved on from the specific problem he had (for which the answer was "hire a freelancer" or at least "I can't solve this for you just standing here with a beer and without a computer") to talking about computer science in general. To his credit, he asked good questions, picked up on the answers immediately, and asked smart follow-ups. But a lot of stuff that's second nature to us CS people was totally new and surprising to him.
The big one, which isn't surprising in hindsight but which we didn't get to until late in the conversation, was that computer science isn't the same as programming. There was also the fact that complexity/Big-O makes a real difference, and that the Halting Problem/unsolvability exists. It kinda made me feel like I wasn't a great ambassador for CS.
My actual question here is: how do you explain computer science to people when you have not a year or a semester, but just an hour, or even only five minutes?
*(This question might be a little outside the typical scope for this site, but it's still relatively early in the beta, so I figured let's give it a shot.)* | 2017/06/21 | [
"https://cseducators.stackexchange.com/questions/918",
"https://cseducators.stackexchange.com",
"https://cseducators.stackexchange.com/users/1166/"
] | I regularly have to explain what *computer science* is to parents, and I have lately settled into this explanation:
Technology keeps changing all the time. You get used to the menus in Microsoft Word, and then they change it to the Ribbon. You learn to program buttons in Java using Applets, and then Applets get removed from every major browser as a security risk.
But there are some things that *never* change, because they're in the realms of mathematics, or they are fundamental organizing principles. For instance, computer right now work in binary, 1s and 0s. The properties of binary numbers themselves aren't going to change no matter what new technology comes around tomorrow. We might create a computer that's not based on binary, but the properties of binary itself are fixed. This is the realm of computer science. Computer science is the foundational stuff that doesn't change.
It's highly mathematical, highly theoretical, and there are a lot of proofs involved, but when you study computer science, you are studying the deeper question in the nature of computation itself, and that's stuff that never gets dated. | I'll attempt a self-answer here, based on hindsight and a few previous experiences where I went in knowing I wanted to do this.
I've found that starting off with an analogy helps a lot of the time. Friends and co-workers have reported similar results in my super unscientific poll. The one we use is along the lines of
>
> Computer science has as much to do with programming as architecture has to do with bricklaying
>
>
>
or
>
> CS is to coding as astronomy is to telescopes
>
>
>
It can be helpful to try to make the analogy with the listener's own profession, as long as it doesn't backfire by derailing the conversation.
This then leads into
>
> Computer science is an academic field. It's theoretical. Programming is more practical; it's a tool.
>
>
>
In my story above, I segued from this into the Halting Problem and efficiency. Looking back, I think that was too big of a jump, at least when presented as abstract concepts. I like the phone book example mentioned in [Peter's answer](https://cseducators.stackexchange.com/a/932/1166). I think I'd modify it this way:
>
> One big part of computer science is "algorithms," which is a fancy word for "figuring out a good way to do things." A good example of this is finding someone's number in the phone book. You could just open the book to random places and hope you get lucky. You could start on page one and start reading straight through until you find the person you want. You could take advantage of the alphabetical sorting and index to see what page the people with similar names start on.
>
>
> Using the index is clearly smarter than repeatedly picking random pages. Coming up with these better ways to do things; that's computer science. The details get really complicated (and are a big part of the field) but it turns out that what seem like small differences in efficiency, or memory usage, or other factors like that, can make a **huge** difference how good an algorithm is in the real world.
>
>
> Now, once you have the plan, you might want to tell someone else how to do it. I could tell someone the exact same phone book search plan in English, or Spanish, or Hindi. I could tell a computer how to do it in C++, or Java, or Ruby. Programming is just a way of communicating instructions to a computer, the same way human languages are a way of communicating information to other people.
>
>
>
The downside of this answer is that it doesn't get into the mathematical foundation of CS, or how CS is about unchanging fundamental concepts. But I'm beginning to think that's not a big problem... such topics might be beyond the scope of a five-minute intro for a complete layperson. |
918 | I was at a party a few days ago with a doctor (the medical kind, not the research kind) who was thinking about writing a computer program to solve a scheduling problem at work. Someone introduced him to me because I have a CS degree and worked as a software engineer for a few years.
It wasn't long before we moved on from the specific problem he had (for which the answer was "hire a freelancer" or at least "I can't solve this for you just standing here with a beer and without a computer") to talking about computer science in general. To his credit, he asked good questions, picked up on the answers immediately, and asked smart follow-ups. But a lot of stuff that's second nature to us CS people was totally new and surprising to him.
The big one, which isn't surprising in hindsight but which we didn't get to until late in the conversation, was that computer science isn't the same as programming. There was also the fact that complexity/Big-O makes a real difference, and that the Halting Problem/unsolvability exists. It kinda made me feel like I wasn't a great ambassador for CS.
My actual question here is: how do you explain computer science to people when you have not a year or a semester, but just an hour, or even only five minutes?
*(This question might be a little outside the typical scope for this site, but it's still relatively early in the beta, so I figured let's give it a shot.)* | 2017/06/21 | [
"https://cseducators.stackexchange.com/questions/918",
"https://cseducators.stackexchange.com",
"https://cseducators.stackexchange.com/users/1166/"
] | I would explain it like this:
In reality, you have to solve problems on your daily basis. It may be a time problem, like "how do I get these five tasks done it just 1 hour?" or "how can I stack these boxes so that they all fit into the cupboard?".
Computer science is in many ways equal to solving these problems, only that the problems are of a little more mathematical and logical manner.
One rather common problem of computer science is "how do I sort a list of numbers?". When a person is given this task, he or she will most likely pick out the lowest or highest number first, put it onto the sorted list and continue from the start until no numbers remain in the unsorted list. This is one solution for the sorting problem, and computer scientists often have to solve this task too. As you can imagine, like described above, it will take a relatively long time to sort all the numbers, as you will repeatedly look at all numbers to sort out the lowest / highest one. So one person once thought "how could I solve this problem faster?" and maybe created an algorithm to solve the task for example twice as fast as the original approach.
Solving problems, not only using the most intuitive way which often tends to be very slow, but thinking about a more complex and strategical approach, to get a given task done as fast as possible, this is a major part of computer science. | Dealing with (my) parents who are not particularly aware of computers or the difference between a server and a database, I believe I have a fairly simple answer for this question.
*Computer science* is the theory and study of how computers work, algorithms (in layman's terms, a process to solve a problem), and how to think like a computer in order to manipulate it to do what you/the client/whoever want.
*Programming* is the actual act of applying the theory and manipulation of the machine. They often get mixed up because programming is such an integral part of CS but is, in fact, only a part of it.
This explanation in some form has had a fairly positive response to me. Or, if you're particularly pressed for time: "Programming is part of computer science, but CS is a lot more focused on the understanding of how the computer works." |
918 | I was at a party a few days ago with a doctor (the medical kind, not the research kind) who was thinking about writing a computer program to solve a scheduling problem at work. Someone introduced him to me because I have a CS degree and worked as a software engineer for a few years.
It wasn't long before we moved on from the specific problem he had (for which the answer was "hire a freelancer" or at least "I can't solve this for you just standing here with a beer and without a computer") to talking about computer science in general. To his credit, he asked good questions, picked up on the answers immediately, and asked smart follow-ups. But a lot of stuff that's second nature to us CS people was totally new and surprising to him.
The big one, which isn't surprising in hindsight but which we didn't get to until late in the conversation, was that computer science isn't the same as programming. There was also the fact that complexity/Big-O makes a real difference, and that the Halting Problem/unsolvability exists. It kinda made me feel like I wasn't a great ambassador for CS.
My actual question here is: how do you explain computer science to people when you have not a year or a semester, but just an hour, or even only five minutes?
*(This question might be a little outside the typical scope for this site, but it's still relatively early in the beta, so I figured let's give it a shot.)* | 2017/06/21 | [
"https://cseducators.stackexchange.com/questions/918",
"https://cseducators.stackexchange.com",
"https://cseducators.stackexchange.com/users/1166/"
] | I would explain it like this:
In reality, you have to solve problems on your daily basis. It may be a time problem, like "how do I get these five tasks done it just 1 hour?" or "how can I stack these boxes so that they all fit into the cupboard?".
Computer science is in many ways equal to solving these problems, only that the problems are of a little more mathematical and logical manner.
One rather common problem of computer science is "how do I sort a list of numbers?". When a person is given this task, he or she will most likely pick out the lowest or highest number first, put it onto the sorted list and continue from the start until no numbers remain in the unsorted list. This is one solution for the sorting problem, and computer scientists often have to solve this task too. As you can imagine, like described above, it will take a relatively long time to sort all the numbers, as you will repeatedly look at all numbers to sort out the lowest / highest one. So one person once thought "how could I solve this problem faster?" and maybe created an algorithm to solve the task for example twice as fast as the original approach.
Solving problems, not only using the most intuitive way which often tends to be very slow, but thinking about a more complex and strategical approach, to get a given task done as fast as possible, this is a major part of computer science. | I don't know if this will help you, but I often find myself in the position of explaining the difference between CS and IT to students / prospective students / parents, and I use the experience of being a one-time emergency medical technician to help.
I compare the difference between CS and IT to the difference between medical doctors and EMTs. As an EMT, I was required by law to follow the protocols established by physicians, who get to do the experimenting and the researching and the paper-writing. As an IT worker, you will be handed a set of tools (databases, operating systems, programming languages) and have to work with what the researchers (the Computer Scientists) come up with. The world needs IT workers as much as they need EMTs, so it isn't less, just different.
It's not perfect, but I teach at a two-year school, so it's enough to get students thinking about which major to choose. |
918 | I was at a party a few days ago with a doctor (the medical kind, not the research kind) who was thinking about writing a computer program to solve a scheduling problem at work. Someone introduced him to me because I have a CS degree and worked as a software engineer for a few years.
It wasn't long before we moved on from the specific problem he had (for which the answer was "hire a freelancer" or at least "I can't solve this for you just standing here with a beer and without a computer") to talking about computer science in general. To his credit, he asked good questions, picked up on the answers immediately, and asked smart follow-ups. But a lot of stuff that's second nature to us CS people was totally new and surprising to him.
The big one, which isn't surprising in hindsight but which we didn't get to until late in the conversation, was that computer science isn't the same as programming. There was also the fact that complexity/Big-O makes a real difference, and that the Halting Problem/unsolvability exists. It kinda made me feel like I wasn't a great ambassador for CS.
My actual question here is: how do you explain computer science to people when you have not a year or a semester, but just an hour, or even only five minutes?
*(This question might be a little outside the typical scope for this site, but it's still relatively early in the beta, so I figured let's give it a shot.)* | 2017/06/21 | [
"https://cseducators.stackexchange.com/questions/918",
"https://cseducators.stackexchange.com",
"https://cseducators.stackexchange.com/users/1166/"
] | I regularly have to explain what *computer science* is to parents, and I have lately settled into this explanation:
Technology keeps changing all the time. You get used to the menus in Microsoft Word, and then they change it to the Ribbon. You learn to program buttons in Java using Applets, and then Applets get removed from every major browser as a security risk.
But there are some things that *never* change, because they're in the realms of mathematics, or they are fundamental organizing principles. For instance, computer right now work in binary, 1s and 0s. The properties of binary numbers themselves aren't going to change no matter what new technology comes around tomorrow. We might create a computer that's not based on binary, but the properties of binary itself are fixed. This is the realm of computer science. Computer science is the foundational stuff that doesn't change.
It's highly mathematical, highly theoretical, and there are a lot of proofs involved, but when you study computer science, you are studying the deeper question in the nature of computation itself, and that's stuff that never gets dated. | Dealing with (my) parents who are not particularly aware of computers or the difference between a server and a database, I believe I have a fairly simple answer for this question.
*Computer science* is the theory and study of how computers work, algorithms (in layman's terms, a process to solve a problem), and how to think like a computer in order to manipulate it to do what you/the client/whoever want.
*Programming* is the actual act of applying the theory and manipulation of the machine. They often get mixed up because programming is such an integral part of CS but is, in fact, only a part of it.
This explanation in some form has had a fairly positive response to me. Or, if you're particularly pressed for time: "Programming is part of computer science, but CS is a lot more focused on the understanding of how the computer works." |
25,666 | The major limitations of decision tree approaches to data analysis that I know of are:
1. Provide less information on the relationship between the predictors and the response.
2. Biased toward predictors with more variance or levels.
3. Can have issues with highly collinear predictors.
4. Can have poor prediction accuracy for responses with low sample sizes.
Are there any others? Are they robust to traditional statistical assumptions such as homogeneity, normality, independence? | 2017/12/14 | [
"https://datascience.stackexchange.com/questions/25666",
"https://datascience.stackexchange.com",
"https://datascience.stackexchange.com/users/43318/"
] | Simple decision trees have some limitations listed below. Fortunately, some of these can be fixed used ensemble learning techniques (think bagging, boosting...).
Concerning limitations :
* Trees tend to overfit quickly at the bottom. If you have few observations in last nodes, poor decision can be taken. In this situation, consider reducing the number of levels of your tree or using pruning.
* Trees can be unstable because small variations in the data might result in a completely different tree being generated.
* Decision trees perform greedy search of best splits at each node. This is particularly true for CART based implementation which tests all possible splits. For a continuous variable, this represents 2^(n-1) - 1 possible splits with n the number of observations in current node.
* For classification, if some classes dominate, it can create biased trees. It is therefore recommended to balance the dataset prior to fitting.
Also, Some distributions can be hard to learn for a decision tree. An example below (XOR) :
[](https://i.stack.imgur.com/dUeZP.png) | 1)**Over Fitting** is one of the most practical difficulty for decision tree models. This problem gets solved by setting constraints on model parameters and pruning.
2)**Not fit for continuous variables**: While working with continuous numerical variables, decision tree looses information when it categorizes variables in different categories. |
21,159,889 | I am very very new to AWS S3.
I have the following questions,
Question 1) Is it possible to have folders and sub-folders in S3 buckets?
For e.g. as below:
Here \*\*Root folder 'Folder' has 2 sub-folders and a file. Then Sub-folder1 has 2 sub-folders and a file. etc.
Question 2) If i have the above structure in S3, How can I retrieve the data by Java code usinf AWS SDK for Java? | 2014/01/16 | [
"https://Stackoverflow.com/questions/21159889",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/2652197/"
] | In aws s3, every file is an object. If you want to upload a specific file in say folder1 your object key should be folder1/filename.ext, if in subfolder of folder1 then it should be folder1/subfolder/filename.ext. So your question 1 is possible even though it is practically not a directory.
When requesting for objects in the folder you can use delimiter and prefix to obtain objects in specific folder see <http://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketGET.html> and <http://docs.aws.amazon.com/AmazonS3/latest/dev/ListingObjectKeysUsingJava.html> | Yes, you can group S3 objects in a [logical hierarchy](https://docs.aws.amazon.com/AmazonS3/latest/user-guide/using-folders.html).
Yes, you can retrieve objects using any support language, including Java. The web has plenty of examples of how to do this, and it's quite simple. The canonical example is [Get an Object using the AWS SDK for Java](https://docs.aws.amazon.com/AmazonS3/latest/dev/RetrievingObjectUsingJava.html). |
2,842,308 | I am collaborating with someone on a project and currently use Skype for collaboration. I like it because we can be on a call to say things that are hard to say by typing out. We can share our screens so we can help with code writing. And we can use the text chat to copy-paste code between each other. We also use Subversion for version control.
I just wanted to know what other people used for collaborating with others so I could see whats out there to use.
Thanks! | 2010/05/16 | [
"https://Stackoverflow.com/questions/2842308",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/304725/"
] | By the way, Google docs help a lot too here! And come at a great price - free!
Their tools, comparable to Word, Excel are all free and read for collaboration. | You also need an issue tracker. I prefer [Redmine](http://www.redmine.org/) which brings on a bunch of other project management features as well. |
2,842,308 | I am collaborating with someone on a project and currently use Skype for collaboration. I like it because we can be on a call to say things that are hard to say by typing out. We can share our screens so we can help with code writing. And we can use the text chat to copy-paste code between each other. We also use Subversion for version control.
I just wanted to know what other people used for collaborating with others so I could see whats out there to use.
Thanks! | 2010/05/16 | [
"https://Stackoverflow.com/questions/2842308",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/304725/"
] | By the way, Google docs help a lot too here! And come at a great price - free!
Their tools, comparable to Word, Excel are all free and read for collaboration. | We're are leveraging email for project related collaboration with this tool:
<http://yoxel.com/personal-commitment-manager.html>
We also use Skype alot. |
2,842,308 | I am collaborating with someone on a project and currently use Skype for collaboration. I like it because we can be on a call to say things that are hard to say by typing out. We can share our screens so we can help with code writing. And we can use the text chat to copy-paste code between each other. We also use Subversion for version control.
I just wanted to know what other people used for collaborating with others so I could see whats out there to use.
Thanks! | 2010/05/16 | [
"https://Stackoverflow.com/questions/2842308",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/304725/"
] | By the way, Google docs help a lot too here! And come at a great price - free!
Their tools, comparable to Word, Excel are all free and read for collaboration. | For service oriented businesses, such as programming, you may benefit in collaboration from a well rounded application that lets you manage multiple aspects of your work.
I'm not sure what you use besides Skype right now, but I'm assuming somehow you're taking care of other aspects of your business too, most likely through email or some small scale CRM. If you want to help speed up your workflow and save some time, WORKetc could be worth checking into. It combines CRM with PM and Billing, but brings collaboration to all of these as well. Basically, under one app you manage all clients, their projects, and can bill them either through your own system or by integrating merchants like Paypal. Because in WORKetc you manage everything centrally, you don't need to jump between a list of apps to find specific information, and this can be especially useful when collaborating with others (which you can do for free btw). |
2,842,308 | I am collaborating with someone on a project and currently use Skype for collaboration. I like it because we can be on a call to say things that are hard to say by typing out. We can share our screens so we can help with code writing. And we can use the text chat to copy-paste code between each other. We also use Subversion for version control.
I just wanted to know what other people used for collaborating with others so I could see whats out there to use.
Thanks! | 2010/05/16 | [
"https://Stackoverflow.com/questions/2842308",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/304725/"
] | You also need an issue tracker. I prefer [Redmine](http://www.redmine.org/) which brings on a bunch of other project management features as well. | We're are leveraging email for project related collaboration with this tool:
<http://yoxel.com/personal-commitment-manager.html>
We also use Skype alot. |
2,842,308 | I am collaborating with someone on a project and currently use Skype for collaboration. I like it because we can be on a call to say things that are hard to say by typing out. We can share our screens so we can help with code writing. And we can use the text chat to copy-paste code between each other. We also use Subversion for version control.
I just wanted to know what other people used for collaborating with others so I could see whats out there to use.
Thanks! | 2010/05/16 | [
"https://Stackoverflow.com/questions/2842308",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/304725/"
] | You also need an issue tracker. I prefer [Redmine](http://www.redmine.org/) which brings on a bunch of other project management features as well. | For service oriented businesses, such as programming, you may benefit in collaboration from a well rounded application that lets you manage multiple aspects of your work.
I'm not sure what you use besides Skype right now, but I'm assuming somehow you're taking care of other aspects of your business too, most likely through email or some small scale CRM. If you want to help speed up your workflow and save some time, WORKetc could be worth checking into. It combines CRM with PM and Billing, but brings collaboration to all of these as well. Basically, under one app you manage all clients, their projects, and can bill them either through your own system or by integrating merchants like Paypal. Because in WORKetc you manage everything centrally, you don't need to jump between a list of apps to find specific information, and this can be especially useful when collaborating with others (which you can do for free btw). |
2,842,308 | I am collaborating with someone on a project and currently use Skype for collaboration. I like it because we can be on a call to say things that are hard to say by typing out. We can share our screens so we can help with code writing. And we can use the text chat to copy-paste code between each other. We also use Subversion for version control.
I just wanted to know what other people used for collaborating with others so I could see whats out there to use.
Thanks! | 2010/05/16 | [
"https://Stackoverflow.com/questions/2842308",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/304725/"
] | We're are leveraging email for project related collaboration with this tool:
<http://yoxel.com/personal-commitment-manager.html>
We also use Skype alot. | For service oriented businesses, such as programming, you may benefit in collaboration from a well rounded application that lets you manage multiple aspects of your work.
I'm not sure what you use besides Skype right now, but I'm assuming somehow you're taking care of other aspects of your business too, most likely through email or some small scale CRM. If you want to help speed up your workflow and save some time, WORKetc could be worth checking into. It combines CRM with PM and Billing, but brings collaboration to all of these as well. Basically, under one app you manage all clients, their projects, and can bill them either through your own system or by integrating merchants like Paypal. Because in WORKetc you manage everything centrally, you don't need to jump between a list of apps to find specific information, and this can be especially useful when collaborating with others (which you can do for free btw). |
12,804 | I really want to know what a paronym is because we're supposed use them in class. | 2011/02/16 | [
"https://english.stackexchange.com/questions/12804",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/-1/"
] | There is no different nuance in meaning as you describe in any dialect of English I am aware of.
The *a/an* pattern is a purely phonological pattern; using one or the other has no impact on meaning. The use is simply governed by the sound of the following word. So, we say:
>
> * *A* boy *("boy" starts with consonant sound)*
> * *An* old boy *("old" starts with vowel sound)*
> * *An* hour *("hour" starts with a vowel sound)*
> * *A* used automobile *("used" starts with a consonant sound)*
> * *An* extremely tired man *("extremely" starts with a vowel sound)*
>
>
>
Whatever sound comes directly after the indefinite article determines whether it takes the *a* form or the *an* form. It doesn't matter if this is a noun, adjective, adverb, or anything else.
Now, there are some dialects that do things differently, but that difference amounts to allowing *a* more often (usually with [free variation](http://en.wikipedia.org/wiki/Free_variation)). Again, semantics does not come into the picture.
If there is any true nuance in meaning for you, then it is something that (as far as I know) is attested only in your [idiolect](http://en.wikipedia.org/wiki/Idiolect). | The general rule is that *an* is used when the following word starts with a vowel sound. The rule is also valid for *English*.
* an eagle
* a young boy
* a young animal
* an elephant
* a young elephant
* an English man
* an English airport
Nobody gives a different meaning to *a English nerd* and *an English nerd*; they see the first as not grammatical. |
50,641,790 | I am not into SSL at all, so bear with me please. I have no idea how to start to actually solve my problem.
**Current situation:**
* 1x Webserver with Webspace for a Website and it includes a Domain Administration, also to order SSL Certificates etc.
* 1x Different Webserver at Amazon Web Services with a PHP-based Software on it with Login etc.
A Subdomain that I created in the Domain Administration is pointing via DNS to the IP of the AWS.
**What I need:**
I want an https Connection (SSL) for the Subdomain that is pointing to the AWS so that the connection/login is secure.
My question is what I have to do on the side where I have the Domain Administration and after that what I have to do on the side of the AWS.
Thank you so much! | 2018/06/01 | [
"https://Stackoverflow.com/questions/50641790",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/9879998/"
] | You have several options in hand,
* If you already have a SSL certificate purchased, you can include it inside the webserver (e.g; configure apache for SSL).
If you plan to use free SSL certificates from Amazon, you can use one of the following options after creating a SSL certificate in AWS Certificate Manager.
* Create a AWS CloudFront Distribution and attach the SSL certificate there while configuring an origin to forward traffic to the specific web server. However, you need to create the SSL certificate in North Virginia region and there won't be any upfront costs for CloudFront). CloudFront acts as a proxy and you can explicitly instruct to cache the static content reducing the load for web server and improving the performance.
* The other option is to create a Application Load Balancer (ALB) and attach the SSL certificate there ( Create the SSL certificate in the same region) while forwarding traffic to the web server. However, this will add a monthly reoccurring costs for the ALB. | All you need to do is, on AWS ACM (AWS Certificate Manager) procure a certificate for your subdomain and use AWS ELB to use the certificate and point to the AWS webserver.
After this use the ELB IP in the DNS settings.
There are other options too like procuring the subdomain certificate and installing it on the webserver on AWS. |
50,261,067 | This happens in the API Explorer and using the .NET client API. In the API Explorer, I was trying to use the query param, but eventually I just removed it and now send the request with no params, and it still turns around 400 even though I am authenticating successfully with OAuth2 in browser.
Why is this endpoint broken?
<https://developers.google.com/admin-sdk/directory/v1/reference/users/list> | 2018/05/09 | [
"https://Stackoverflow.com/questions/50261067",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/843567/"
] | The problem was the `customer` field was not filled in. It must contain a valid customer id. Once I populated that, it worked.
Really wish Google would work on providing better error feedback and improve their docs. This field (as of today) is still listed as optional. | As the documentation says:
>
> either the customer or the domain parameter must be provided
>
>
>
I tried to specify `domain` name and it worked. |
4,420 | In Thai there are particles which can be used at the end of many sentences to make them more polite. Different particles are used by male and female speakers:
* "ครับ" (kráp) : male
* "ค่ะ" (kâ) : female
Lao is so closely related to Thai that they are apparently mostly mutually comprehensible.
Yet one of the first things I noticed in the speech when I crossed the border from Thailand to Laos is the complete lack of such particles in Lao. I never hear anybody say them and none of the materials I've seen on Lao describe them. In Thai it's one of the first things you are taught.
* Does Lao have etymologically related words that serve other functions?
* Did Lao have them formerly but they slipped out of usage in the remote or recent past?
* Are they an innovation in Thai since after the point in time the languages diverged from their common ancestor? | 2013/09/10 | [
"https://linguistics.stackexchange.com/questions/4420",
"https://linguistics.stackexchange.com",
"https://linguistics.stackexchange.com/users/51/"
] | This video from Youtube, [Stories behind Polite Endings in Thai ครับ/ค่ะ and Lao](http://www.youtube.com/watch?v=rMlSEKwqyhM), answers all of your questions. Let me write down some excerpts from there:
The polite particles came from legacy words of master/servant relations. As you know, social status and relationship of people in a conversation impacts on the style of such conversation;
>
> Does Lao have etymologically related words that serve other functions?
>
>
>
Yes, these words are *master*, ຂ້ານ້ອຍ *servant*, and similar ones.
There are some [usage rules](http://laomate.activeboard.com/forum.spark?aBID=98894&p=3&topicID=40950083), not using ຂ້ານ້ອຍ twice: e.g. "my name is John", *I* is already ຂ້ານ້ອຍ, so the polite particle is omitted.
Also, ເຈົ້າ ("lord") is used in meaning of "yes".
>
> Did Lao have them formerly but they slipped out of usage in the remote or recent past?
>
>
>
Yes, they have been used as both pronouns and polite particles, quite like in Thai.
>
> Are they an innovation in Thai [...]
>
>
>
Not necessarily. Off the top of my head, take the English word *sir*. It used to have the meaning of *"title of honor of a knight or baronet"* ([link](http://www.etymonline.com/index.php?term=sir)), but later became a *respectful form of address or salutation*. | Another word widely heard in Laos when they want to make a sentence more polite, I hear "ໂດຍ" or "ໂດຍຂ້ານ້ອຍ". After asking some friends who speak Lao as a mothertongue, they always use "ໂດย", the shorten form of "ໂດຍຂ້ານ້ອຍ" which is older and more polite, with people in general but prefer using "ເຈົ້າ" with people in higher age and rank, additionally for official use. |
151,584 | I've found interesting sounding reference written in Czech.
If wanting to read non-English references, then are there translators that work well for science papers? | 2020/07/09 | [
"https://academia.stackexchange.com/questions/151584",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/125350/"
] | I would say [DeepL](https://www.deepl.com/translator). It's a free-to-use, machine-learning based translator. It deals with technical terms way better than google translate does. However, it doesn't support Czech, so it probably wont solve your problem.
Of course, it's not perfect, and as stated in other comments here... the more complex the subject is, the less probable it is that any translator will give you an accurate answer. | Based on getting things like google translate to translate technical terms, I have to go with **NO**.
Works fine for simple language but technical language is a different game.
Even people who claim to be bi-lingual cannot translate technical information. I had this argument once and gave a lady who claimed she could translate anything a paper on stresses and buckling in 3 dimensions which proved she could not. :)
I have done some work translating a paper or two between 2 languages and it is challenging even for an engineer who understands the concepts to make sure what is stated is what is meant. |
86,913 | Even though I got ~~banned~~ suspended, I'm able to mark a question as a favorite. Is this functionally correct? | 2011/04/11 | [
"https://meta.stackexchange.com/questions/86913",
"https://meta.stackexchange.com",
"https://meta.stackexchange.com/users/-1/"
] | If by *ban*, you mean that stackoverflow isn't accepting questions/answers from your account, then, why would it be appropriate to prevent you from marking questions as favourites?
The ban is to prevent negative behaviour that detracts from the value of the site, i.e. poor questions/answers. You being able to mark a question as a favourite doesn't, and I'd be hard presssed to see how it could, detract from the value of the site (unless you sit and mark, lets say, all the questions, as favourites). | There was a bug in the javascript that made it *seem* like you could favorite questions - the server still rejected any attempts you made.
A fix will be deployed in the next push. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.