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228 | 1 | 249 | null | 8 | 75 | Going through the presentation and material of Summingbird by Twitter, one of the reasons that is mentioned for using Storm and Hadoop clusters together in Summingbird is that processing through Storm results in cascading of error. In order to avoid this cascading of error and accumulation of it, Hadoop cluster is used... | Cascaded Error in Apache Storm | CC BY-SA 3.0 | null | 2014-06-01T12:51:25.040 | 2014-06-10T03:42:51.637 | null | null | 339 | [
"bigdata",
"apache-hadoop"
] |
229 | 2 | null | 227 | 9 | null | This is kind of like asking about the tradeoffs between frying pan and your drawer of silverware. They are not two things you compare, really. You might use them together as part of a larger project.
Hadoop itself is not one thing, but a name for a federation of services, like HDFS, Hive, HBase, MapReduce, etc. Storm ... | null | CC BY-SA 3.0 | null | 2014-06-01T19:48:41.693 | 2014-06-01T19:48:41.693 | null | null | 21 | null |
230 | 2 | null | 223 | 7 | null | In general, you don't want to use XML tags to tag documents in this way because tags may overlap.
[UIMA](http://uima.apache.org/), [GATE](http://gate.ac.uk/) and similar NLP frameworks denote the tags separate from the text. Each tag, such as `Person`, `ACME`, `John` etc. is stored as the position that the tag begins ... | null | CC BY-SA 3.0 | null | 2014-06-02T15:03:35.940 | 2014-06-02T15:03:35.940 | null | null | 178 | null |
231 | 1 | 287 | null | 10 | 6442 | I want to test the accuracy of a methodology. I ran it ~400 times, and I got a different classification for each run. I also have the ground truth, i.e., the real classification to test against.
For each classification I computed a confusion matrix. Now I want to aggregate these results in order to get the overall conf... | How to get an aggregate confusion matrix from n different classifications | CC BY-SA 3.0 | null | 2014-06-05T09:00:27.950 | 2014-06-11T09:39:34.373 | 2014-06-05T15:21:40.640 | 84 | 133 | [
"classification",
"confusion-matrix",
"accuracy"
] |
232 | 2 | null | 231 | 4 | null | There are a few ways to achieve your "master confusion matrix".
- Sum all the confusion matrices together: Like you suggested, summing this results in a confusion matrix. The problem with this is you can not interpret totals.
- Average the entries. This method is the same as number one, but you divide each entry b... | null | CC BY-SA 3.0 | null | 2014-06-06T14:55:18.867 | 2014-06-06T14:55:18.867 | null | null | 375 | null |
233 | 2 | null | 130 | 3 | null | To complete Damien's answer, an example of dimensionality reduction in NLP is a [topic model](http://en.wikipedia.org/wiki/Topic_model), where you represent the document by a vector indicating the weights of its constituent topics.
| null | CC BY-SA 3.0 | null | 2014-06-08T07:03:43.710 | 2014-06-08T07:03:43.710 | null | null | 381 | null |
234 | 1 | null | null | 5 | 470 | As Yann LeCun [mentioned](http://www.reddit.com/r/MachineLearning/comments/25lnbt/ama_yann_lecun/chisdw1), a number of PhD programs in data science will be popping up in the next few years.
[NYU](http://datascience.nyu.edu/academics/programs/) already have one, where Prof.LeCun is at right now.
A statistics or cs PhD i... | Data science Ph.D. program, what do you think? | CC BY-SA 3.0 | null | 2014-06-09T04:43:03.497 | 2014-06-10T03:21:56.473 | null | null | 386 | [
"knowledge-base"
] |
235 | 1 | 237 | null | 3 | 1572 | Data visualization is an important sub-field of data science and python programmers need to have available toolkits for them.
Is there a Python API to Tableau?
Are there any Python based data visualization toolkits?
| Are there any python based data visualization toolkits? | CC BY-SA 4.0 | null | 2014-06-09T08:34:29.337 | 2019-06-08T03:11:24.957 | 2019-06-08T03:11:24.957 | 29169 | 122 | [
"python",
"visualization"
] |
236 | 2 | null | 234 | 2 | null | No-one knows since no-one's completed one of these PhD programs yet! However, I would look at the syllabus and the teachers to base my decision. It all depends on what you want to do; industry or academia?
| null | CC BY-SA 3.0 | null | 2014-06-09T18:02:00.613 | 2014-06-09T18:02:00.613 | null | null | 381 | null |
237 | 2 | null | 235 | 11 | null | There is a Tablaeu API and you can use Python to use it, but maybe not in the sense that you think. There is a Data Extract API that you could use to import your data into Python and do your visualizations there, so I do not know if this is going to answer your question entirely.
As in the first comment you can use Mat... | null | CC BY-SA 3.0 | null | 2014-06-09T19:52:41.847 | 2014-06-09T19:52:41.847 | null | null | 59 | null |
238 | 2 | null | 234 | 1 | null | I think this question assumes a false premise. As a student at NYU, I only know of a Masters in Data Science. You linked to a page that confirms this.
It's hard to gauge the benefit of a program that doesn't exist yet.
| null | CC BY-SA 3.0 | null | 2014-06-09T21:36:44.297 | 2014-06-09T21:36:44.297 | null | null | 395 | null |
241 | 2 | null | 234 | 3 | null | It seems to me that the premise of a PhD is to expand knowledge in some little slice of the world. Since a "data scientist" is by nature is somewhat of a jack-of-all-trades it does seem a little odd to me. A masters program seems much more appropriate.
What do you hope to gain from a PhD? If the rigor scares (or bores)... | null | CC BY-SA 3.0 | null | 2014-06-09T21:51:53.793 | 2014-06-09T21:51:53.793 | null | null | 403 | null |
242 | 2 | null | 227 | 13 | null | MapReduce: A fault tolerant distributed computational framework. MapReduce allows you to operate over huge amounts of data- with a lot of work put in to prevent failure due to hardware. MapReduce is a poor choice for computing results on the fly because it is slow. (A typical MapReduce job takes on the order of minutes... | null | CC BY-SA 3.0 | null | 2014-06-09T21:57:30.240 | 2014-06-10T23:33:28.443 | 2014-06-10T23:33:28.443 | 406 | 406 | null |
243 | 2 | null | 184 | 5 | null | A variety of methods are available to the user. The support documentation gives walkthroughs and tips for when one or another model is most appropriate.
[This page](https://developers.google.com/prediction/docs/pmml-schema) shows the following learning methods:
- "AssociationModel"
- "ClusteringModel"
- "General... | null | CC BY-SA 3.0 | null | 2014-06-10T01:36:27.520 | 2014-06-10T01:43:47.883 | 2014-06-10T01:43:47.883 | 432 | 432 | null |
244 | 2 | null | 138 | 4 | null | Coming from a programmers perspective, frameworks rarely target performance as the highest priority. If your library is going to be widely leveraged the things people are likely to value most are ease of use, flexibility, and reliability.
Performance is generally valued in secondary competitive libraries. "X library ... | null | CC BY-SA 3.0 | null | 2014-06-10T01:40:23.263 | 2014-06-10T01:40:23.263 | null | null | 434 | null |
245 | 2 | null | 234 | 3 | null | Computer Science is itself a multi-disciplinary field which has varying requirements among universities. For example, Stockholm University does not require any math above algebra for its CS programs (some courses may have higher requirements, but not often).
I am not sure what you mean by a machine learning program ... | null | CC BY-SA 3.0 | null | 2014-06-10T01:54:40.647 | 2014-06-10T01:54:40.647 | null | null | 432 | null |
246 | 2 | null | 134 | 4 | null | There will definitely be a translation task at the end if you prototype using just mongo.
When you run a MapReduce task on mongodb, it has the data source and structure built in. When you eventually convert to hadoop, your data structures might not look the same. You could leverage the mongodb-hadoop connector to acc... | null | CC BY-SA 3.0 | null | 2014-06-10T02:42:02.050 | 2014-06-10T02:42:02.050 | null | null | 434 | null |
247 | 2 | null | 235 | 12 | null | [Bokeh](http://bokeh.pydata.org/) is an excellent data visualization library for python.
[NodeBox](http://www.cityinabottle.org/nodebox/) is another that comes to mind.
| null | CC BY-SA 3.0 | null | 2014-06-10T02:50:51.153 | 2014-06-10T02:50:51.153 | null | null | 434 | null |
248 | 2 | null | 234 | 3 | null | A cash cow program? No. PhD programs are never cash cows.
I don't know why you couldn't be a professor with a PhD in data science. Rarely does a professor of a given course have to have a specific degree in order to teach it.
As far as publishing goes, there are any number of related journals that would accept paper... | null | CC BY-SA 3.0 | null | 2014-06-10T03:21:56.473 | 2014-06-10T03:21:56.473 | null | null | 434 | null |
249 | 2 | null | 228 | 4 | null | Twitter uses Storm for real-time processing of data. Problems can happen with real-time data. Systems might go down. Data might be inadvertently processed twice. Network connections can be lost. A lot can happen in a real-time system.
They use hadoop to reliably process historical data. I don't know specifics, ... | null | CC BY-SA 3.0 | null | 2014-06-10T03:42:51.637 | 2014-06-10T03:42:51.637 | null | null | 434 | null |
250 | 2 | null | 184 | 3 | null | Google does not publish the models they use, but they specifically do not support models from the PMML specification.
If you look closely at the documentation on [this page](https://developers.google.com/prediction/docs/pmml-schema), you will notice that the model selection within the schema is greyed out indicating th... | null | CC BY-SA 3.0 | null | 2014-06-10T04:47:13.040 | 2014-06-10T04:47:13.040 | null | null | 434 | null |
251 | 2 | null | 138 | 4 | null | Having done the rewriting game over and over myself (and still doing it), my immediate reaction was adaptability.
While frameworks and libraries have a huge arsenal of (possibly intertwinable) routines for standard tasks, their framework property often (always?) disallows shortcuts. In fact, most frameworks have some ... | null | CC BY-SA 3.0 | null | 2014-06-10T05:57:13.897 | 2014-06-10T05:57:13.897 | null | null | 451 | null |
252 | 1 | null | null | 3 | 852 | There seem to be at least 2 ways to connect to HBase from external application, with language other then Java (i.e. Python):
- HBase Thrift API
- HBase Stargate (REST API)
Does anyone know which one should be used in which circumstances?
I.e. what are their main differences, and pros/cons?
| HBase connector - Thrift or REST | CC BY-SA 3.0 | null | 2014-06-10T06:19:46.510 | 2014-06-10T07:56:45.587 | null | null | 88 | [
"bigdata",
"apache-hadoop"
] |
253 | 1 | 256 | null | 39 | 21145 | An aspiring data scientist here. I don't know anything about Hadoop, but as I have been reading about Data Science and Big Data, I see a lot of talk about Hadoop. Is it absolutely necessary to learn Hadoop to be a Data Scientist?
| Do I need to learn Hadoop to be a Data Scientist? | CC BY-SA 3.0 | null | 2014-06-10T06:20:20.817 | 2022-08-26T05:51:09.493 | null | null | 456 | [
"bigdata",
"apache-hadoop"
] |
254 | 2 | null | 169 | 7 | null | Actually there are more than one question to answer here:
- How to work on schemaless/loose/missing data
- How to label a person (from what I understand unsupervised) and create an identifier
- How to train your system so that it can tell you which attributes you should use in order to identify the person
As Rube... | null | CC BY-SA 3.0 | null | 2014-06-10T07:10:45.057 | 2014-06-10T07:10:45.057 | null | null | 463 | null |
255 | 2 | null | 253 | 2 | null | You should learn Hadoop if you want to be work as data scientist, but maybe before starting with Hadoop you should read something about ETL or Big Data... this book could be a good starting point: [http://www.amazon.com/Big-Data-Principles-practices-scalable/dp/1617290343](http://rads.stackoverflow.com/amzn/click/16172... | null | CC BY-SA 3.0 | null | 2014-06-10T07:28:49.127 | 2014-06-10T07:28:49.127 | null | null | 466 | null |
256 | 2 | null | 253 | 48 | null | Different people use different tools for different things. Terms like Data Science are generic for a reason. A data scientist could spend an entire career without having to learn a particular tool like hadoop. Hadoop is widely used, but it is not the only platform that is capable of managing and manipulating data, e... | null | CC BY-SA 3.0 | null | 2014-06-10T07:30:53.510 | 2014-06-10T08:21:19.197 | 2014-06-10T08:21:19.197 | 434 | 434 | null |
257 | 2 | null | 253 | 4 | null | Yes, you should learn a platform that is capable of dissecting your problem as a data parallel problem. Hadoop is one. For your simple needs (design patterns like counting, aggregation, filtering etc.) you need Hadoop and for more complex Machine Learning stuff like doing some Bayesian, SVM you need Mahout which in tur... | null | CC BY-SA 3.0 | null | 2014-06-10T07:42:57.470 | 2014-06-10T07:42:57.470 | null | null | 11 | null |
258 | 2 | null | 252 | 2 | null | Thrift is generally faster because the data being exchanged is smaller. Stargate offers a web service which is an integration method that is widely supported, which is a concern when you are working with commercial products with limited integration possibilities.
In a closed environment where everything is controlled,... | null | CC BY-SA 3.0 | null | 2014-06-10T07:56:45.587 | 2014-06-10T07:56:45.587 | null | null | 434 | null |
259 | 2 | null | 155 | 20 | null | I would like to point to [The Open Data Census](http://national.census.okfn.org/). It is an initiative of the Open Knowledge Foundation based on contributions from open data advocates and experts around the world.
The value of Open data Census is open, community driven, and systematic effort to collect and update the ... | null | CC BY-SA 3.0 | null | 2014-06-10T08:04:20.400 | 2014-06-10T08:04:20.400 | null | null | 454 | null |
260 | 2 | null | 191 | 2 | null | The algorithm that is used in this case is called [one-vs-all classifier](https://class.coursera.org/ml-003/lecture/38) or multiclass classifier.
In your case you have to take one class, e. g. number 1 , mark it as positive and combine the rest seven classes in one negative class. The neural network will output the pr... | null | CC BY-SA 3.0 | null | 2014-06-10T08:38:27.093 | 2014-06-10T08:38:27.093 | null | null | 454 | null |
261 | 2 | null | 196 | 3 | null | You could take a look at CN2 rule learner in [Orange 2](http://orange.biolab.si/orange2/)
| null | CC BY-SA 4.0 | null | 2014-06-10T09:21:14.013 | 2020-08-06T11:04:09.857 | 2020-08-06T11:04:09.857 | 98307 | 480 | null |
262 | 1 | 293 | null | 40 | 22477 | What are the advantages of HDF compared to alternative formats? What are the main data science tasks where HDF is really suitable and useful?
| What are the advantages of HDF compared to alternative formats? | CC BY-SA 4.0 | null | 2014-06-10T09:26:06.593 | 2021-07-02T00:43:22.377 | 2020-04-14T16:54:08.463 | null | 97 | [
"data-formats",
"hierarchical-data-format"
] |
263 | 2 | null | 172 | 8 | null | Unfortunately, parallelization is not yet implemented in pandas. You can join [this github issue](http://github.com/pydata/pandas/issues/5751) if you want to participate in the development of this feature.
I don't know any "magic unicorn package" for this purposes, so the best thing will be write your own solution. But... | null | CC BY-SA 3.0 | null | 2014-06-10T09:41:34.697 | 2014-06-10T09:41:34.697 | null | null | 478 | null |
264 | 2 | null | 22 | 4 | null | You can also give the Expectation Maximization clustering algorithm a try. It can work on categorical data and will give you a statistical likelihood of which categorical value (or values) a cluster is most likely to take on.
| null | CC BY-SA 3.0 | null | 2014-06-10T10:48:58.457 | 2014-06-10T10:48:58.457 | null | null | 490 | null |
265 | 1 | 285 | null | 42 | 45677 | I have a variety of NFL datasets that I think might make a good side-project, but I haven't done anything with them just yet.
Coming to this site made me think of machine learning algorithms and I wondering how good they might be at either predicting the outcome of football games or even the next play.
It seems to me t... | Can machine learning algorithms predict sports scores or plays? | CC BY-SA 3.0 | null | 2014-06-10T10:58:58.447 | 2020-08-20T18:25:42.540 | 2015-03-02T12:33:11.007 | 553 | 434 | [
"machine-learning",
"sports"
] |
266 | 1 | 272 | null | 12 | 3010 | Being new to machine-learning in general, I'd like to start playing around and see what the possibilities are.
I'm curious as to what applications you might recommend that would offer the fastest time from installation to producing a meaningful result.
Also, any recommendations for good getting-started materials on the... | What are some easy to learn machine-learning applications? | CC BY-SA 3.0 | null | 2014-06-10T11:05:47.273 | 2014-06-12T17:58:21.467 | null | null | 434 | [
"machine-learning"
] |
268 | 2 | null | 266 | 5 | null | I think [Weka](http://www.cs.waikato.ac.nz/ml/weka/) is a good starting point. You can do a bunch of stuff like supervised learning or clustering and easily compare a large set of algorithms na methodologies.
Weka's manual is actually a book on machine learning and data mining that can be used as introductory material.... | null | CC BY-SA 3.0 | null | 2014-06-10T11:36:19.287 | 2014-06-10T11:36:19.287 | null | null | 418 | null |
269 | 2 | null | 265 | 9 | null | Definitely they can.
I can target you to a [nice paper](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.56.7448&rep=rep1&type=pdf). Once I used it for soccer league results prediction algorithm implementation, primarily aiming at having some value against bookmakers.
From paper's abstract:
>
a Bayesian dynami... | null | CC BY-SA 3.0 | null | 2014-06-10T11:37:28.293 | 2014-06-25T16:03:21.447 | 2014-06-25T16:03:21.447 | 322 | 97 | null |
270 | 2 | null | 265 | 7 | null | Machine learning and statistical techniques can improve the forecast, but nobody can predict the real result.
There was a kaggle competition a few month ago about [predicting the 2014 NCAA Tournament](https://www.kaggle.com/c/march-machine-learning-mania). You can read the Competition Forum to get a better idea on what... | null | CC BY-SA 3.0 | null | 2014-06-10T11:39:19.603 | 2014-06-10T11:39:19.603 | null | null | 478 | null |
271 | 2 | null | 265 | 8 | null | It has been shown before that machine learning techniques can be applied for predicting sport results. Simple google search should give you a bunch of results.
However, it has also been showed (for NFL btw) that very complex predictive models, simple predictive models, questioning people, or crowd knowledge by utilisin... | null | CC BY-SA 3.0 | null | 2014-06-10T11:49:23.777 | 2014-06-10T11:49:23.777 | null | null | 418 | null |
272 | 2 | null | 266 | 13 | null | I would recommend to start with some MOOC on machine learning. For example Andrew Ng's [course](https://www.coursera.org/course/ml) at coursera.
You should also take a look at [Orange](http://orange.biolab.si/) application. It has a graphical interface and probably it is easier to understand some ML techniques using it... | null | CC BY-SA 3.0 | null | 2014-06-10T11:53:07.737 | 2014-06-10T11:53:07.737 | null | null | 478 | null |
273 | 2 | null | 253 | 2 | null | You can apply data science techniques to data on one machine so the answer to the question as the OP phrased it, is no.
| null | CC BY-SA 3.0 | null | 2014-06-10T12:10:28.713 | 2014-06-10T15:04:01.177 | 2014-06-10T15:04:01.177 | 498 | 498 | null |
274 | 2 | null | 262 | 12 | null | One benefit is wide support - C, Java, Perl, Python, and R all have HDF5 bindings.
Another benefit is speed. I haven't ever seen it benchmarked, but HDF is supposed to be faster than SQL databases.
I understand that it is very good when used with both large sets of scientific data and time series data - network monito... | null | CC BY-SA 3.0 | null | 2014-06-10T12:57:04.307 | 2014-06-10T12:57:04.307 | null | null | 434 | null |
275 | 2 | null | 155 | 26 | null | For time series data in particular, [Quandl](http://www.quandl.com/) is an excellent resource -- an easily browsable directory of (mostly) clean time series.
One of their coolest features is [open-data stock prices](http://blog.quandl.com/blog/quandl-open-data/) -- i.e. financial data that can be edited wiki-style, and... | null | CC BY-SA 3.0 | null | 2014-06-10T13:17:48.433 | 2014-06-10T13:17:48.433 | null | null | 508 | null |
276 | 2 | null | 155 | 10 | null | Not all government data is listed on data.gov - [Sunlight Foundation](http://sunlightfoundation.com/blog/2014/02/21/open-data-inventories-ready-for-human-consumption/) put together a [set of spreadsheets](https://drive.google.com/folderview?id=0B4QuErjcV2a0WXVDOURwbzh6S2s&usp=sharing) back in February describing sets o... | null | CC BY-SA 3.0 | null | 2014-06-10T13:38:31.207 | 2014-06-10T13:38:31.207 | null | null | 434 | null |
277 | 2 | null | 266 | 11 | null | To be honest, I think that doing some projects will teach you much more than doing a full course. One reason is that doing a project is more motivating and open-ended than doing assignments.
A course, if you have the time AND motivation (real motivation), is better than doing a project. The other commentators have made... | null | CC BY-SA 3.0 | null | 2014-06-10T14:25:41.903 | 2014-06-10T14:25:41.903 | null | null | 518 | null |
278 | 2 | null | 266 | 2 | null | Assuming you're familiar with programming I would recommend looking at [scikit-learn](http://scikit-learn.org/stable/). It has especially nice help pages that can serve as mini-tutorials/a quick tour through machine learning. Pick an area you find interesting and work through the examples.
| null | CC BY-SA 3.0 | null | 2014-06-10T14:30:33.667 | 2014-06-10T14:30:33.667 | null | null | 524 | null |
279 | 2 | null | 155 | 19 | null | There is also another resource provided by The Guardian, the British Daily on their website. The datasets published by the Guardian Datablog are all hosted. Datasets related to Football Premier League Clubs' accounts, Inflation and GDP details of UK, Grammy awards data etc.
The datasets are available at
- http://www.... | null | CC BY-SA 3.0 | null | 2014-06-10T14:57:47.810 | 2014-06-11T16:30:06.930 | 2014-06-11T16:30:06.930 | 514 | 514 | null |
280 | 1 | null | null | 8 | 164 | I am developing a system that is intended to capture the "context" of user activity within an application; it is a framework that web applications can use to tag user activity based on requests made to the system. It is hoped that this data can then power ML features such as context aware information retrieval.
I'm ha... | Feature selection for tracking user activity within an application | CC BY-SA 3.0 | null | 2014-06-10T15:08:54.073 | 2020-06-19T08:28:09.320 | null | null | 531 | [
"feature-selection"
] |
282 | 2 | null | 265 | 14 | null | Yes. Why not?!
With so much of data being recorded in each sport in each game, smart use of data could lead us to obtain important insights regarding player performance.
Some examples:
- Baseball: In the movie Moneyball (which is an adaptation of the Moneyball book), Brad Pitt plays a character who analyses player sta... | null | CC BY-SA 4.0 | null | 2014-06-10T16:25:24.223 | 2020-08-20T18:25:04.213 | 2020-08-20T18:25:04.213 | 98307 | 514 | null |
284 | 2 | null | 280 | 5 | null | Well, this may not answer the question thoroughly, but since you're dealing with information retrieval, it may be of some use. [This page](http://moz.com/search-ranking-factors) mantains a set of features and associated correlations with page-ranking methods of search engines. As a disclaimer from the webpage itself:
>... | null | CC BY-SA 3.0 | null | 2014-06-10T17:06:54.950 | 2014-06-10T17:06:54.950 | null | null | 84 | null |
285 | 2 | null | 265 | 19 | null | There are a lot of good questions about Football (and sports, in general) that would be awesome to throw to an algorithm and see what comes out. The tricky part is to know what to throw to the algorithm.
A team with a good RB could just pass on 3rd-and-short just because the opponents would probably expect run, for ins... | null | CC BY-SA 4.0 | null | 2014-06-10T17:15:52.953 | 2019-01-23T14:36:40.430 | 2019-01-23T14:36:40.430 | 553 | 553 | null |
287 | 2 | null | 231 | 5 | null | I do not know a standard answer to this, but I thought about it some times ago and I have some ideas to share.
When you have one confusion matrix, you have more or less a picture of how you classification model confuse (mis-classify) classes. When you repeat classification tests you will end up having multiple confusi... | null | CC BY-SA 3.0 | null | 2014-06-10T17:32:19.120 | 2014-06-11T09:39:34.373 | 2014-06-11T09:39:34.373 | 108 | 108 | null |
288 | 2 | null | 280 | 5 | null | The goal determines the features, so I would initially take as many as possible, then use cross validation to select the optimal subset.
My educated guess is that a Markov model would work. If you discretize the action space (e.g., select this menu item, press that button, etc.), you can predict the next action based o... | null | CC BY-SA 3.0 | null | 2014-06-10T17:36:11.580 | 2014-06-11T01:19:18.183 | 2014-06-11T01:19:18.183 | 381 | 381 | null |
289 | 1 | 291 | null | 10 | 580 | Yann LeCun mentioned in his [AMA](http://www.reddit.com/r/MachineLearning/comments/25lnbt/ama_yann_lecun/) that he considers having a PhD very important in order to get a job at a top company.
I have a masters in statistics and my undergrad was in economics and applied math, but I am now looking into ML PhD programs. M... | Qualifications for PhD Programs | CC BY-SA 3.0 | null | 2014-06-10T17:56:34.847 | 2015-09-10T20:17:35.897 | 2015-09-10T20:17:35.897 | 560 | 560 | [
"education"
] |
290 | 2 | null | 266 | 2 | null | I found the pluralsight course [Introduction to machine learning encog](http://pluralsight.com/training/courses/TableOfContents?courseName=introduction-to-machine-learning-encog&highlight=abhishek-kumar_introduction-to-machine-learning-encog-m2-applications!abhishek-kumar_introduction-to-machine-learning-encog-m3-tasks... | null | CC BY-SA 3.0 | null | 2014-06-10T18:22:32.610 | 2014-06-10T18:22:32.610 | null | null | 571 | null |
291 | 2 | null | 289 | 10 | null | If I were you I would take a MOOC or two (e.g., [Algorithms, Part I](https://www.coursera.org/course/algs4partI), [Algorithms, Part II](https://www.coursera.org/course/algs4partII), [Functional Programming Principles in Scala](https://www.coursera.org/course/progfun)), a good book on data structures and algorithms, the... | null | CC BY-SA 3.0 | null | 2014-06-10T18:55:39.010 | 2014-06-10T18:55:39.010 | null | null | 381 | null |
292 | 2 | null | 289 | 7 | null | Your time would probably be better spent on Kaggle than in a PhD program. When you read the stories by winners ([Kaggle blog](http://blog.kaggle.com/)) you'll see that it takes a large amount of practice and the winners are not just experts of one single method.
On the other hand, being active and having a plan in a Ph... | null | CC BY-SA 3.0 | null | 2014-06-10T19:43:11.860 | 2014-06-10T19:43:11.860 | null | null | 587 | null |
293 | 2 | null | 262 | 37 | null | Perhaps a good way to paraphrase the question is, what are the advantages compared to alternative formats?
The main alternatives are, I think: a database, text files, or another packed/binary format.
The database options to consider are probably a columnar store or NoSQL, or for small self-contained datasets SQLite. ... | null | CC BY-SA 3.0 | null | 2014-06-10T20:28:54.613 | 2014-06-10T20:28:54.613 | null | null | 26 | null |
294 | 2 | null | 253 | 9 | null | As a former Hadoop engineer, it is not needed but it helps. Hadoop is just one system - the most common system, based on Java, and a ecosystem of products, which apply a particular technique "Map/Reduce" to obtain results in a timely manner. Hadoop is not used at Google, though I assure you they use big data analytics.... | null | CC BY-SA 3.0 | null | 2014-06-10T20:40:25.623 | 2014-06-10T20:40:25.623 | null | null | 602 | null |
295 | 2 | null | 289 | 5 | null | I am glad you also found Yann LeCun's AMA page, it's very useful.
Here are my opinions
Q: Should I take some intro software engineering courses at my local University to make myself a stronger candidate?
A: No, you need to take more math courses. It's not the applied stuff that's hard, it's the theory stuff. I don't ... | null | CC BY-SA 3.0 | null | 2014-06-10T20:43:28.533 | 2014-06-10T20:43:28.533 | null | null | 386 | null |
296 | 2 | null | 128 | 44 | null | HDP is an extension of LDA, designed to address the case where the number of mixture components (the number of "topics" in document-modeling terms) is not known a priori. So that's the reason why there's a difference.
Using LDA for document modeling, one treats each "topic" as a distribution of words in some known voc... | null | CC BY-SA 3.0 | null | 2014-06-10T21:50:51.347 | 2014-06-10T21:50:51.347 | null | null | 14 | null |
297 | 2 | null | 130 | 7 | null | As in @damienfrancois answer feature selection is about selecting a subset of features. So in NLP it would be selecting a set of specific words (the typical in NLP is that each word represents a feature with value equal to the frequency of the word or some other weight based on TF/IDF or similar).
Dimensionality reduct... | null | CC BY-SA 3.0 | null | 2014-06-10T22:26:53.623 | 2015-10-20T03:28:37.247 | 2015-10-20T03:28:37.247 | 381 | 418 | null |
298 | 2 | null | 289 | 7 | null | You already have a Masters in Statistics, which is great! In general, I'd suggest to people to take as much statistics as they can, especially Bayesian Data Analysis.
Depending on what you want to do with your PhD, you would benefit from foundational courses in the discipline(s) in your application area. You already ... | null | CC BY-SA 3.0 | null | 2014-06-10T22:29:52.873 | 2014-06-10T22:29:52.873 | null | null | 609 | null |
300 | 2 | null | 103 | 4 | null | Topological Data Analysis is a method explicitly designed for the setting you describe. Rather than a global distance metric, it relies only on a local metric of proximity or neighborhood. See: [Topology and data](http://www.ams.org/bull/2009-46-02/S0273-0979-09-01249-X/S0273-0979-09-01249-X.pdf) and [Extracting insigh... | null | CC BY-SA 3.0 | null | 2014-06-10T23:20:16.670 | 2014-06-10T23:20:16.670 | null | null | 609 | null |
301 | 2 | null | 52 | 11 | null | One reason that data cleaning is rarely fully automated is that there is so much judgment required to define what "clean" means given your particular problem, methods, and goals.
It may be as simple as imputing values for any missing data, or it might be as complex as diagnosing data entry errors or data transformation... | null | CC BY-SA 3.0 | null | 2014-06-11T00:32:54.887 | 2014-06-11T00:32:54.887 | null | null | 609 | null |
302 | 2 | null | 280 | 3 | null | I've seen a few similar systems over the years. I remember a company called ClickTrax which if I'm not mistaken got bought by Google and some of their features are now part of Google Analytics.
Their purpose was marketing, but the same concept can be applied to user experience analytics. The beauty of their system wa... | null | CC BY-SA 3.0 | null | 2014-06-11T00:44:20.517 | 2014-06-11T00:44:20.517 | null | null | 434 | null |
303 | 2 | null | 224 | 3 | null | This isn't my area of specialty and I'm not familiar with Moses, but I found this after some searching.
I think you are looking for GIZA++. You'll see GIZA++ listed in the "Training" section (left menu) on the Moses home page, as the second step. GIZA++ is briefly described in tutorial fashion [here](https://stackov... | null | CC BY-SA 3.0 | null | 2014-06-11T01:09:06.100 | 2014-06-11T01:09:06.100 | 2017-05-23T12:38:53.587 | -1 | 609 | null |
305 | 1 | 309 | null | 12 | 3082 | There is plenty of hype surrounding Hadoop and its eco-system. However, in practice, where many data sets are in the terabyte range, is it not more reasonable to use [Amazon RedShift](http://aws.amazon.com/redshift/) for querying large data sets, rather than spending time and effort building a Hadoop cluster?
Also, h... | Does Amazon RedShift replace Hadoop for ~1XTB data? | CC BY-SA 3.0 | null | 2014-06-11T04:24:04.183 | 2015-01-28T18:42:06.763 | 2014-06-11T15:02:46.890 | 434 | 534 | [
"apache-hadoop",
"map-reduce",
"aws"
] |
306 | 2 | null | 305 | 3 | null | Personally, I don't think it's all that difficult to set up a hadoop cluster, but I know that it is sometimes painful when you are getting started.
HDFS size limitations well exceed a TB (or did you mean exabyte?). If I'm not mistaken it scales to yottabytes or some other measurement that I don't even know the word fo... | null | CC BY-SA 3.0 | null | 2014-06-11T05:17:12.253 | 2014-06-11T05:17:12.253 | null | null | 434 | null |
307 | 1 | null | null | 14 | 3467 | I have read lot of blogs\article on how different type of industries are using Big Data Analytic. But most of these article fails to mention
- What kinda data these companies used. What was the size of the data
- What kinda of tools technologies they used to process the data
- What was the problem they were facing a... | Big data case study or use case example | CC BY-SA 3.0 | null | 2014-06-11T06:07:45.767 | 2020-08-16T16:54:32.553 | 2016-08-17T10:41:41.383 | 3151 | 496 | [
"data-mining",
"bigdata",
"usecase"
] |
308 | 2 | null | 307 | 14 | null | News outlets tend to use "Big Data" pretty loosely. Vendors usually provide case studies surrounding their specific products. There aren't a lot out there for open source implementations, but they do get mentioned. For instance, Apache isn't going to spend a lot of time building a case study on hadoop, but vendors l... | null | CC BY-SA 3.0 | null | 2014-06-11T06:49:04.070 | 2014-06-11T06:54:42.593 | 2014-06-11T06:54:42.593 | 434 | 434 | null |
309 | 2 | null | 305 | 12 | null | tl;dr: They markedly differ in many aspects and I can't think Redshift will replace Hadoop.
-Function
You can't run anything other than SQL on Redshift. Perhaps most importantly, you can't run any type of custom functions on Redshift. In Hadoop you can, using many languages (Java, Python, Ruby.. you name it). For exa... | null | CC BY-SA 3.0 | null | 2014-06-11T06:51:19.143 | 2014-06-11T09:07:33.570 | 2014-06-11T09:07:33.570 | 638 | 638 | null |
310 | 1 | null | null | 17 | 2865 | I'm working on improving an existing supervised classifier, for classifying {protein} sequences as belonging to a specific class (Neuropeptide hormone precursors), or not.
There are about 1,150 known "positives", against a background of about 13 million protein sequences ("Unknown/poorly annotated background"), or abou... | One-Class discriminatory classification with imbalanced, heterogenous Negative background? | CC BY-SA 3.0 | null | 2014-06-11T10:11:59.397 | 2020-08-16T13:00:45.530 | null | null | 555 | [
"machine-learning",
"data-mining",
"python",
"classification"
] |
311 | 2 | null | 310 | 5 | null | The way I would attack the problem, in general, is to leverage statistical analysis like Principal Component Analysis or Ordinary Least Squares to help determine what attributes within these protein sequences are best suited to classify proteins as Neuropeptide hormone precursors.
In order to do that, you'll have to co... | null | CC BY-SA 4.0 | null | 2014-06-11T11:24:19.963 | 2020-08-16T13:00:45.530 | 2020-08-16T13:00:45.530 | 50406 | 434 | null |
312 | 2 | null | 215 | 5 | null | Therriault, really happy to hear you are using Vertica! Full disclosure, I am the chief data scientist there :) . The workflow you describe is exactly what I encounter quite frequently and I am a true believer in preprocessing those very large datasets in the database prior to any pyODBC and pandas work. I'd suggest cr... | null | CC BY-SA 3.0 | null | 2014-06-11T11:32:13.433 | 2014-06-11T11:32:13.433 | null | null | 655 | null |
313 | 1 | null | null | 29 | 3323 | What are the books about the science and mathematics behind data science? It feels like so many "data science" books are programming tutorials and don't touch things like data generating processes and statistical inference. I can already code, what I am weak on is the math/stats/theory behind what I am doing.
If I am r... | Books about the "Science" in Data Science? | CC BY-SA 3.0 | null | 2014-06-11T13:28:35.980 | 2016-02-21T04:02:38.847 | 2016-02-21T04:02:38.847 | 11097 | 663 | [
"statistics",
"reference-request"
] |
314 | 2 | null | 313 | 14 | null | If I could only recomend one to you, it would be: [The Elements of Statistical Learning and Prediction](http://rads.stackoverflow.com/amzn/click/0387848576) by Hastie, Tibshirani and Friedman. It provides the math/statistics behind a lot of commonly used techniques in data science.
For Bayesian Techniques, [Bayesian D... | null | CC BY-SA 3.0 | null | 2014-06-11T13:49:08.970 | 2014-06-11T13:49:08.970 | null | null | 178 | null |
316 | 2 | null | 59 | 10 | null | As Konstantin has pointed, R performs all its computation in the system's memory i.e. RAM. Hence, RAM capacity is a very important constraint for computation intensive operations in R. Overcoming this constraint, data is being stored these days in HDFS systems, where data isn't loaded onto memory and program is run ins... | null | CC BY-SA 3.0 | null | 2014-06-11T16:25:34.747 | 2014-06-11T16:25:34.747 | null | null | 514 | null |
317 | 2 | null | 266 | 2 | null | If you already know R Studio, then the caret package is a good place to start. Here are some tutorials:
- https://class.coursera.org/predmachlearn-002
- http://caret.r-forge.r-project.org/index.html
With R and caret you can easily load and splice data sets, feature reduction, principal component analysis, and trai... | null | CC BY-SA 3.0 | null | 2014-06-11T16:56:59.660 | 2014-06-11T16:56:59.660 | null | null | 680 | null |
318 | 2 | null | 266 | 2 | null | If you can reproduce the 6x3 grid of graphs from the banner of the [http://scikit-learn.org/](http://scikit-learn.org/) page then you will have learnt some ML and some Python. You didn't mention a language. Python is easy enough to learn very quickly, and scikit-learn has a wide range of algorithms implemented.
Then tr... | null | CC BY-SA 3.0 | null | 2014-06-11T17:24:53.610 | 2014-06-11T17:24:53.610 | null | null | 471 | null |
319 | 1 | null | null | 10 | 2177 | I've built an artificial neural network in python using the scipy.optimize.minimize (Conjugate gradient) optimization function.
I've implemented gradient checking, double checked everything etc and I'm pretty certain it's working correctly.
I've run it a few times and it reaches 'Optimization terminated successfully' h... | Debugging Neural Networks | CC BY-SA 3.0 | null | 2014-06-11T18:22:36.267 | 2014-06-12T18:08:07.507 | 2014-06-12T16:43:59.513 | 381 | 691 | [
"machine-learning",
"python",
"neural-network"
] |
320 | 2 | null | 319 | 9 | null | There are so many ways to go wrong with a neural net that it's going to be difficult to debug. Also, to address your intuition, each additional hidden layer makes learning much harder. With that said, here are some possibilities:
- You have added weight decay. Adding more layers adds more weights which increases your ... | null | CC BY-SA 3.0 | null | 2014-06-11T20:34:51.873 | 2014-06-11T20:34:51.873 | null | null | 574 | null |
323 | 1 | null | null | 5 | 9516 | The setup is simple: binary classification using a simple decision tree, each node of the tree has a single threshold applied on a single feature. In general, building a ROC curve requires moving a decision threshold over different values and computing the effect of that change on the true positive rate and the false p... | How can we calculate AUC for a simple decision tree? | CC BY-SA 3.0 | null | 2014-06-11T23:52:37.823 | 2021-02-18T20:33:30.027 | null | null | 418 | [
"machine-learning"
] |
324 | 1 | null | null | -2 | 619 | I would like to extract news about a company from online news by using the RODBC package in R. I would then like to use the extracted data for sentiment analysis. I want to accomplish this in such a way that the positive news is assigned a value of +1, the negative news is assigned a value of -1, and the neutral news i... | How can I extract news about a particular company from various websites using RODBC package in R? And perform sentiment analysis on the data? | CC BY-SA 4.0 | null | 2014-06-12T03:11:00.033 | 2019-06-11T14:43:33.343 | 2019-06-11T14:43:33.343 | 29169 | 714 | [
"r",
"text-mining",
"sentiment-analysis"
] |
325 | 2 | null | 324 | 2 | null | This isn't a question with a simple answer, so all I can really do is point you in the right direction.
The RODBC package isn't meant to extract data online, it's meant to pull data from a database. If you will be leveraging that package, it will be after you pull data down from the web.
Jeffrey Bean put together a [s... | null | CC BY-SA 3.0 | null | 2014-06-12T05:17:46.453 | 2014-06-12T05:17:46.453 | null | null | 434 | null |
326 | 1 | null | null | 127 | 119318 | I'm just starting to develop a [machine learning](https://en.wikipedia.org/wiki/Machine_learning) application for academic purposes. I'm currently using R and training myself in it. However, in a lot of places, I have seen people using Python.
What are people using in academia and industry, and what is the recommendati... | Python vs R for machine learning | CC BY-SA 4.0 | null | 2014-06-12T06:04:48.243 | 2022-07-11T21:50:49.357 | 2019-06-10T15:56:58.013 | 29169 | 721 | [
"machine-learning",
"r",
"python"
] |
327 | 2 | null | 326 | 26 | null | There is nothing like "python is better" or "R is much better than x".
The only fact I know is that in the industry allots of people stick to python because that is what they learned at the university. The python community is really active and have a few great frameworks for ML and data mining etc.
But to be honest, ... | null | CC BY-SA 3.0 | null | 2014-06-12T07:05:05.653 | 2014-06-12T07:05:05.653 | null | null | 115 | null |
328 | 2 | null | 326 | 7 | null | There is no "better" language. I have tried both of them and I am comfortable with Python so I work with Python only. Though I am still learning stuff, but I haven't encounter any roadblock with Python till now. The good thing about Python is community is too good and you can get a lot of help on the Internet easily. O... | null | CC BY-SA 3.0 | null | 2014-06-12T08:30:49.757 | 2014-06-12T08:30:49.757 | null | null | 456 | null |
330 | 2 | null | 235 | 4 | null | You can also checkout the seaborn package for statistical charts.
| null | CC BY-SA 3.0 | null | 2014-06-12T09:57:39.890 | 2014-06-12T09:57:39.890 | null | null | 729 | null |
331 | 2 | null | 326 | 18 | null | Some additional thoughts.
The programming language 'per se' is only a tool. All languages were designed to make some type of constructs more easy to build than others. And the knowledge and mastery of a programming language is more important and effective than the features of that language compared to others.
As far... | null | CC BY-SA 4.0 | null | 2014-06-12T10:09:23.887 | 2018-11-14T18:58:00.230 | 2018-11-14T18:58:00.230 | 62609 | 108 | null |
332 | 2 | null | 323 | 3 | null | In order to build the ROC curve and AUC (Area under curve) you have to have a binary classifier which provides you at classification time, the distribution (or at least a score), not the classification label. To give you an example, suppose you have a binary classification model, with classes $c1$ and $c2$. For a given... | null | CC BY-SA 4.0 | null | 2014-06-12T10:27:14.480 | 2021-02-18T20:33:30.027 | 2021-02-18T20:33:30.027 | 29169 | 108 | null |
334 | 1 | 338 | null | 37 | 19856 | I've now seen two data science certification programs - the [John Hopkins one available at Coursera](https://www.coursera.org/specialization/jhudatascience/1?utm_medium=listingPage) and the [Cloudera one](http://cloudera.com/content/cloudera/en/training/certification/ccp-ds.html).
I'm sure there are others out there.
T... | What do you think of Data Science certifications? | CC BY-SA 3.0 | null | 2014-06-12T10:52:03.410 | 2019-07-11T07:02:42.803 | 2014-06-13T11:35:51.697 | 434 | 434 | [
"education"
] |
335 | 2 | null | 334 | 12 | null | The certification programs you mentioned are really entry level courses. Personally, I think these certificates show only person's persistence and they can be only useful to those who is applying for internships, not the real data science jobs.
| null | CC BY-SA 3.0 | null | 2014-06-12T11:11:35.600 | 2014-06-12T11:11:35.600 | null | null | 478 | null |
336 | 2 | null | 326 | 13 | null | There isn't a silver bullet language that can be used to solve each and every data related problem. The language choice depends on the context of the problem, size of data and if you are working at a workplace you have to stick to what they use.
Personally I use R more often than Python due to its visualization librari... | null | CC BY-SA 3.0 | null | 2014-06-12T11:30:20.943 | 2014-06-12T11:30:20.943 | null | null | 733 | null |
337 | 2 | null | 326 | 15 | null | I would add to what others have said till now. There is no single answer that one language is better than other.
Having said that, R has a better community for data exploration and learning. It has extensive visualization capabilities. Python, on the other hand, has become better at data handling since introduction of ... | null | CC BY-SA 3.0 | null | 2014-06-12T11:54:59.140 | 2014-06-12T11:54:59.140 | null | null | 735 | null |
338 | 2 | null | 334 | 13 | null | I did the first 2 courses and I'm planning to do all the others too. If you don't know R, it's a really good program. There are assignments and quizzes every week. Many people find some courses very difficult. You are going to have hard time if you don't have any programming experience (even if they say it's not requi... | null | CC BY-SA 3.0 | null | 2014-06-12T12:13:26.940 | 2014-06-12T12:13:26.940 | null | null | 737 | null |
339 | 2 | null | 326 | 110 | null | Some real important differences to consider when you are choosing R or Python over one another:
- Machine Learning has 2 phases. Model Building and Prediction phase. Typically, model building is performed as a batch process and predictions are done realtime. The model building process is a compute intensive process wh... | null | CC BY-SA 3.0 | null | 2014-06-12T12:59:00.663 | 2017-01-17T14:14:47.423 | 2017-01-17T14:14:47.423 | 28021 | 514 | null |
340 | 2 | null | 235 | 5 | null | There's plenty. If you've ever used ggplot2 in R and want to do that in [Python](https://pypi.python.org/pypi/ggplot/0.5.9).
If you want to use a similar visualisation grammar (Vega) and go via [D3](https://github.com/wrobstory/vincent).
Or if you want the full-on 3d: [shizzle](http://docs.enthought.com/mayavi/mayavi/)... | null | CC BY-SA 4.0 | null | 2014-06-12T13:38:10.877 | 2019-04-25T18:59:20.977 | 2019-04-25T18:59:20.977 | 29575 | 471 | null |
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