Tag: code

Cloud Computing with R

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Here is a short list of resources and material I put together as starting points for R and Cloud Computing It’s a bit messy but overall should serve quite comprehensively.

Cloud computing is a commonly used expression to imply a generational change in computing from desktop-servers to remote and massive computing connections,shared computers, enabled by high bandwidth across the internet.

As per the National Institute of Standards and Technology Definition,
Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.

(Citation: The NIST Definition of Cloud Computing

Authors: Peter Mell and Tim Grance
Version 15, 10-7-09
National Institute of Standards and Technology, Information Technology Laboratory
http://csrc.nist.gov/groups/SNS/cloud-computing/cloud-def-v15.doc)

R is an integrated suite of software facilities for data manipulation, calculation and graphical display.

From http://cran.r-project.org/doc/FAQ/R-FAQ.html#R-Web-Interfaces

R Web Interfaces

Rweb is developed and maintained by Jeff Banfield. The Rweb Home Page provides access to all three versions of Rweb—a simple text entry form that returns output and graphs, a more sophisticated JavaScript version that provides a multiple window environment, and a set of point and click modules that are useful for introductory statistics courses and require no knowledge of the R language. All of the Rweb versions can analyze Web accessible datasets if a URL is provided.
The paper “Rweb: Web-based Statistical Analysis”, providing a detailed explanation of the different versions of Rweb and an overview of how Rweb works, was published in the Journal of Statistical Software (http://www.jstatsoft.org/v04/i01/).

Ulf Bartel has developed R-Online, a simple on-line programming environment for R which intends to make the first steps in statistical programming with R (especially with time series) as easy as possible. There is no need for a local installation since the only requirement for the user is a JavaScript capable browser. See http://osvisions.com/r-online/ for more information.

Rcgi is a CGI WWW interface to R by MJ Ray. It had the ability to use “embedded code”: you could mix user input and code, allowing the HTMLauthor to do anything from load in data sets to enter most of the commands for users without writing CGI scripts. Graphical output was possible in PostScript or GIF formats and the executed code was presented to the user for revision. However, it is not clear if the project is still active.

Currently, a modified version of Rcgi by Mai Zhou (actually, two versions: one with (bitmap) graphics and one without) as well as the original code are available from http://www.ms.uky.edu/~statweb/.

CGI-based web access to R is also provided at http://hermes.sdu.dk/cgi-bin/go/. There are many additional examples of web interfaces to R which basically allow to submit R code to a remote server, see for example the collection of links available from http://biostat.mc.vanderbilt.edu/twiki/bin/view/Main/StatCompCourse.

David Firth has written CGIwithR, an R add-on package available from CRAN. It provides some simple extensions to R to facilitate running R scripts through the CGI interface to a web server, and allows submission of data using both GET and POST methods. It is easily installed using Apache under Linux and in principle should run on any platform that supports R and a web server provided that the installer has the necessary security permissions. David’s paper “CGIwithR: Facilities for Processing Web Forms Using R” was published in the Journal of Statistical Software (http://www.jstatsoft.org/v08/i10/). The package is now maintained by Duncan Temple Lang and has a web page athttp://www.omegahat.org/CGIwithR/.

Rpad, developed and actively maintained by Tom Short, provides a sophisticated environment which combines some of the features of the previous approaches with quite a bit of JavaScript, allowing for a GUI-like behavior (with sortable tables, clickable graphics, editable output), etc.
Jeff Horner is working on the R/Apache Integration Project which embeds the R interpreter inside Apache 2 (and beyond). A tutorial and presentation are available from the project web page at http://biostat.mc.vanderbilt.edu/twiki/bin/view/Main/RApacheProject.

Rserve is a project actively developed by Simon Urbanek. It implements a TCP/IP server which allows other programs to use facilities of R. Clients are available from the web site for Java and C++ (and could be written for other languages that support TCP/IP sockets).

OpenStatServer is being developed by a team lead by Greg Warnes; it aims “to provide clean access to computational modules defined in a variety of computational environments (R, SAS, Matlab, etc) via a single well-defined client interface” and to turn computational services into web services.

Two projects use PHP to provide a web interface to R. R_PHP_Online by Steve Chen (though it is unclear if this project is still active) is somewhat similar to the above Rcgi and Rweb. R-php is actively developed by Alfredo Pontillo and Angelo Mineo and provides both a web interface to R and a set of pre-specified analyses that need no R code input.

webbioc is “an integrated web interface for doing microarray analysis using several of the Bioconductor packages” and is designed to be installed at local sites as a shared computing resource.

Rwui is a web application to create user-friendly web interfaces for R scripts. All code for the web interface is created automatically. There is no need for the user to do any extra scripting or learn any new scripting techniques. Rwui can also be found at http://rwui.cryst.bbk.ac.uk.

Finally, the R.rsp package by Henrik Bengtsson introduces “R Server Pages”. Analogous to Java Server Pages, an R server page is typically HTMLwith embedded R code that gets evaluated when the page is requested. The package includes an internal cross-platform HTTP server implemented in Tcl, so provides a good framework for including web-based user interfaces in packages. The approach is similar to the use of the brew package withRapache with the advantage of cross-platform support and easy installation.

Also additional R Cloud Computing Use Cases
http://wwwdev.ebi.ac.uk/Tools/rcloud/

ArrayExpress R/Bioconductor Workbench

Remote access to R/Bioconductor on EBI’s 64-bit Linux Cluster

Start the workbench by downloading the package for your operating system (Macintosh or Windows), or via Java Web Start, and you will get access to an instance of R running on one of EBI’s powerful machines. You can install additional packages, upload your own data, work with graphics and collaborate with colleagues, all as if you are running R locally, but unlimited by your machine’s memory, processor or data storage capacity.

  • Most up-to-date R version built for multicore CPUs
  • Access to all Bioconductor packages
  • Access to our computing infrastructure
  • Fast access to data stored in EBI’s repositories (e.g., public microarray data in ArrayExpress)

Using R Google Docs
http://www.omegahat.org/RGoogleDocs/run.pdf
It uses the XML and RCurl packages and illustrates that it is relatively quick and easy
to use their primitives to interact with Web services.

Using R with Amazon
Citation
http://rgrossman.com/2009/05/17/running-r-on-amazons-ec2/

Amazon’s EC2 is a type of cloud that provides on demand computing infrastructures called an Amazon Machine Images or AMIs. In general, these types of cloud provide several benefits:

  • Simple and convenient to use. An AMI contains your applications, libraries, data and all associated configuration settings. You simply access it. You don’t need to configure it. This applies not only to applications like R, but also can include any third-party data that you require.
  • On-demand availability. AMIs are available over the Internet whenever you need them. You can configure the AMIs yourself without involving the service provider. You don’t need to order any hardware and set it up.
  • Elastic access. With elastic access, you can rapidly provision and access the additional resources you need. Again, no human intervention from the service provider is required. This type of elastic capacity can be used to handle surge requirements when you might need many machines for a short time in order to complete a computation.
  • Pay per use. The cost of 1 AMI for 100 hours and 100 AMI for 1 hour is the same. With pay per use pricing, which is sometimes called utility pricing, you simply pay for the resources that you use.

Connecting to R on Amazon EC2- Detailed tutorials
Ubuntu Linux version
https://decisionstats.com/2010/09/25/running-r-on-amazon-ec2/
and Windows R version
https://decisionstats.com/2010/10/02/running-r-on-amazon-ec2-windows/

Connecting R to Data on Google Storage and Computing on Google Prediction API
https://github.com/onertipaday/predictionapirwrapper
R wrapper for working with Google Prediction API

This package consists in a bunch of functions allowing the user to test Google Prediction API from R.
It requires the user to have access to both Google Storage for Developers and Google Prediction API:
see http://code.google.com/apis/storage/ and http://code.google.com/apis/predict/ for details.

Example usage:

#This example requires you had previously created a bucket named data_language on your Google Storage and you had uploaded a CSV file named language_id.txt (your data) into this bucket – see for details
library(predictionapirwrapper)

and Elastic R for Cloud Computing
http://user2010.org/tutorials/Chine.html

Abstract

Elastic-R is a new portal built using the Biocep-R platform. It enables statisticians, computational scientists, financial analysts, educators and students to use cloud resources seamlessly; to work with R engines and use their full capabilities from within simple browsers; to collaborate, share and reuse functions, algorithms, user interfaces, R sessions, servers; and to perform elastic distributed computing with any number of virtual machines to solve computationally intensive problems.
Also see Karim Chine’s http://biocep-distrib.r-forge.r-project.org/

R for Salesforce.com

At the point of writing this, there seem to be zero R based apps on Salesforce.com This could be a big opportunity for developers as both Apex and R have similar structures Developers could write free code in R and charge for their translated version in Apex on Salesforce.com

Force.com and Salesforce have many (1009) apps at
http://sites.force.com/appexchange/home for cloud computing for
businesses, but very few forecasting and statistical simulation apps.

Example of Monte Carlo based app is here
http://sites.force.com/appexchange/listingDetail?listingId=a0N300000016cT9EAI#

These are like iPhone apps except meant for business purposes (I am
unaware if any university is offering salesforce.com integration
though google apps and amazon related research seems to be on)

Force.com uses a language called Apex  and you can see
http://wiki.developerforce.com/index.php/App_Logic and
http://wiki.developerforce.com/index.php/An_Introduction_to_Formulas
Apex is similar to R in that is OOPs

SAS Institute has an existing product for taking in Salesforce.com data.

A new SAS data surveyor is
available to access data from the Customer Relationship Management
(CRM) software vendor Salesforce.com. at
http://support.sas.com/documentation/cdl/en/whatsnew/62580/HTML/default/viewer.htm#datasurveyorwhatsnew902.htm)

Personal Note-Mentioning SAS in an email to a R list is a big no-no in terms of getting a response and love. Same for being careless about which R help list to email (like R devel or R packages or R help)

For python based cloud see http://pi-cloud.com

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Here comes PySpread- 85,899,345 rows and 14,316,555 columns

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Whats new/ One more open source analytics package. Built like a spreadsheet with an ability to import a million cells-

From http://pyspread.sourceforge.net/index.html

about Pyspread is a cross-platform Python spreadsheet application. It is based on and written in the programming language Python.

Instead of spreadsheet formulas, Python expressions are entered into the spreadsheet cells. Each expression returns a Python object that can be accessed from other cells. These objects can represent anything including lists or matrices.

 Pyspread screenshot
features In pyspread, cells expect Python expressions and return Python objects. Therefore, complex data types such as lists, trees or matrices can be handled within a single cell. Macros can be used for functions that are too complex for a single expression.

Since Python modules can be easily used without external scripts, arbitrary size rational numbers (via gmpy), fixed point decimal numbers for business calculations, (via the decimal module from the standard library) and advanced statistics including plotting functions (via RPy) can be used in the spreadsheet. Everything is directly available from each cell. Just use the grid

Data can be imported and exported using csv files or the clipboard. Other forms of data exchange is possible using external Python modules.

In  order to simplify sparse matrix editing, pyspread features a three dimensional grid that can be sized up to 85,899,345 rows and 14,316,555 columns (64 bit-systems, depends on row height and column width). Note that importing a million cells requires about 500 MB of memory.

The concept of pyspread allows doing everything from each cell that a Python script can do. This may very well include deleting your hard drive or sending your data via the Internet. Of course this is a non-issue if you sandbox properly or if you only use self developed spreadsheets. Since this is not the case for everyone (see the discussion at lwn.net), a GPG signature based trust model for spreadsheet files has been introduced. It ensures that only your own trusted files are executed on loading. Untrusted files are displayed in safe mode. You can trust a file manually. Inspect carefully.

 Pyspread screenshot
requirements Pyspread runs on Linux, Windows and *nix platforms with GTK+ support. There are reports that it works with MacOS X as well. If you would like to contribute by testing on OS X please contact me.

Dependencies

Highly recommended for full functionality

  • PyMe >=0.8.1, Note for Windows™ users: If you want to use signatures without compiling PyMe try out Gpg4win.
  • gmpy >=1.1.0 and
  • rpy >=1.0.3.
maturity Pyspread is in early Beta release. This means that the core functionality is fully implemented but the program needs testing and polish.

and from the wiki

http://sourceforge.net/apps/mediawiki/pyspread/index.php?title=Main_Page

a spreadsheet with more powerful functions and data structures that are accessible inside each cell. Something like Python that empowers you to do things quickly. And yes, it should be free and it should run on Linux as well as on Windows. I looked around and found nothing that suited me. Therefore, I started pyspread.

Concept

  • Each cell accepts any input that works in a Python command line.
  • The inputs are parsed and evaluated by Python’s eval command.
  • The result objects are accessible via a 3D numpy object array.
  • String representations of the result objects are displayed in the cells.

Benefits

  • Each cell returns a Python object. This object can be anything including arrays and third party library objects.
  • Generator expressions can be used efficiently for data manipulation.
  • Efficient numpy slicing is used.
  • numpy methods are accessible for the data.

Installation

  1. Download the pyspread tarball or zip and unzip at a convenient place
  2. In case you do not have it already get and install Python, wxpython and numpy
If you want the examples to work, install gmpy, R and rpy
Really do check the version requirements that are mentioned on http://pyspread.sf.net
  1. Get install privileges (e.g. become root)
  2. Change into the directory and type
python setup.py install
Windows: Replace “python” with your Python interpreter (absolute path)
  1. Become normal user again
  2. Start pyspread by typing
pyspread
  1. Enjoy

Links

Next on Spreadsheet wishlist-

a MSI bundle /Windows Self Installer which has all dependencies bundled in it-linking to PostGresSQL 😉 etc

way to go Mr Martin Manns

mmanns < at > gmx < dot > net

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For R Writers- Inside R

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Hurray I am on Inside -R

http://www.inside-r.org/blogs/2010/11/04/r-apache-next-frontier-r-computing

Thats blog post number 1 there.

Basically Inside R is a go-to site for tips, tricks, packages, as well as blog posts. It thus enhances R Bloggers – but also adds in other multiple features as well.

It is an excellent place for R beginners and learning R. Also it is moderated ( so you wont get the flashy jhing bhang stuff- just your R.

What I really liked is the Pretty R functionality for turning R code -its nifty for color coding R code for use of posting in your blog, journal or article

and when you are there drop them a line for their excellent R support for events (like Pizza, sponsorship) and nifty R packages (doSNOW, foreach, RevoScaler, RevoDeployR) and how much open core makes them look silly?

Come on Revolution- share the open code for RevoScaler package- did you notice any sales dip when you open sourced the other packages? (cue to David Smith to roll his eyes again)

Anyway- all that is part of the R family fun 🙂

Do check http://www.inside-r.org/pretty-r

 

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R Apache – The next frontier of R Computing

I am currently playing/ trying out RApache- one more excellent R product from Vanderbilt’s excellent Dept of Biostatistics and it’s prodigious coder Jeff Horner.

The big ninja himself

I really liked the virtual machine idea- you can download a virtual image of Rapache and play with it- .vmx is easy to create and great to share-

http://rapache.net/vm.html

Basically using R Apache (with an EC2 on backend) can help you create customized dashboards, BI apps, etc all using R’s graphical and statistical capabilities.

What’s R Apache?

As  per

http://biostat.mc.vanderbilt.edu/wiki/Main/RapacheWebServicesReport

Rapache embeds the R interpreter inside the Apache 2 web server. By doing this, Rapache realizes the full potential of R and its facilities over the web. R programmers configure appache by mapping Universal Resource Locaters (URL’s) to either R scripts or R functions. The R code relies on CGI variables to read a client request and R’s input/output facilities to write the response.

One advantage to Rapache’s architecture is robust multi-process management by Apache. In contrast to Rserve and RSOAP, Rapache is a pre-fork server utilizing HTTP as the communications protocol. Another advantage is a clear separation, a loose coupling, of R code from client code. With Rserve and RSOAP, the client must send data and R commands to be executed on the server. With Rapache the only client requirements are the ability to communicate via HTTP. Additionally, Rapache gains significant authentication, authorization, and encryption mechanism by virtue of being embedded in Apache.

Existing Demos of Architechture based on R Apache-

  1. http://rweb.stat.ucla.edu/ggplot2/ An interactive web dashboard for plotting graphics based on csv or Google Spreadsheet Data
  2. http://labs.dataspora.com/gameday/ A demo visualization of a web based dashboard system of baseball pitches by pitcher by player 

 

 

 

 

 

 

 

3. http://data.vanderbilt.edu/rapache/bbplot For baseball results – a demo of a query based web dashboard system- very good BI feel.

Whats coming next in R Apache?

You can  download version 1.1.10 of rApache now. There
are only two significant changes and you don’t have to edit your
apache config or change any code (just recompile rApache and
reinstall):

1) Error reporting should be more informative. both when you
accidentally introduce errors in the Apache config, and when your code
introduces warnings and errors from web requests.

I’ve struggled with this one for awhile, not really knowing what
strategy would be best. Basically, rApache hooks into the R I/O layer
at such a low level that it’s hard to capture all warnings and errors
as they occur and introduce them to the user in a sane manner. In
prior releases, when ROutputErrors was in effect (either the apache
directive or the R function) one would typically see a bunch of grey
boxes with a red outline with a title of RApache Warning/Error!!!.
Unfortunately those grey boxes could contain empty lines, one line of
error, or a few that relate to the lines in previously displayed
boxes. Really a big uninformative mess.

The new approach is to print just one warning box with the title
“”Oops!!! <b>rApache</b> has something to tell you. View source and
read the HTML comments at the end.” and then as the title implies you
can read the HTML comment located at the end of the file… after the
closing html. That way, you’re actually reading how R would present
the warnings and errors to you as if you executed the code at the R
command prompt. And if you don’t use ROutputErrors, the warning/error
messages are printed in the Apache log file, just as they were before,
but nicer 😉

2) Code dispatching has changed so please let me know if I’ve
introduced any strange behavior.

This was necessary to enhance error reporting. Prior to this release,
rApache would use R’s C API exclusively to build up the call to your
code that is then passed to R’s evaluation engine. The advantage to
this approach is that it’s much more efficient as there is no parsing
involved, however all information about parse errors, files which
produced errors, etc. were lost. The new approach uses R’s built-in
parse function to build up the call and then passes it of to R. A
slight overhead, but it should be negligible. So, if you feel that
this approach is too slow OR I’ve introduced bugs or strange behavior,
please let me know.

FUTURE PLANS

I’m gaining more experience building Debian/Ubuntu packages each day,
so hopefully by some time in 2011 you can rely on binary releases for
these distributions and not install rApache from source! Fingers
crossed!

Development on the rApache 1.1 branch will be winding down (save bug
fix releases) as I transition to the 1.2 branch. This will involve
taking out a small chunk of code that defines the rApache development
environment (all the CGI variables and the functions such as
setHeader, setCookie, etc) and placing it in its own R package…
unnamed as of yet. This is to facilitate my development of the ralite
R package, a small single user cross-platform web server.

The goal for ralite is to speed up development of R web applications,
take out a bit of friction in the development process by not having to
run the full rApache server. Plus it would allow users to develop in
the rApache enronment while on windows and later deploy on more
capable server environments. The secondary goal for ralite is it’s use
in other web server environments (nginx and IIS come to mind) as a
persistent per-client process.

And finally, wiki.rapache.net will be the new www.rapache.net once I
translate the manual over… any day now.

From –http://biostat.mc.vanderbilt.edu/wiki/Main/JeffreyHorner

 

 

Not convinced ?- try the demos above.

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Open Source's worst enemy is itself not Microsoft/SAS/SAP/Oracle

The decision of quality open source makers to offer their software at bargain basement prices even to enterprise customers who are used to pay prices many times more-pricing is the reason open source software is taking a long time to command respect in enterprise software.

I hate to be the messenger who brings the bad news to my open source brethren-

but their worst nightmare is not the actions of their proprietary competitors like Oracle, SAP, SAS, Microsoft ( they hate each other even more than open source )

nor the collective marketing tactics which are textbook like (but referred as Fear Uncertainty Doubt by those outside that golden quartet)- it is their own communities and their own cheap pricing.

It is community action which prevents them from offering their software by ridiculously low bargain basement prices. James Dixon, head geek and founder at Pentaho has a point when he says traditional metrics like revenue need o be adjusted for this impact in his article at http://jamesdixon.wordpress.com/2010/11/02/comparing-open-source-and-proprietary-software-markets/

But James, why offer software to enterprise customers at one tenth the next competitor- one reason is open source companies more often than not compete more with their free community version software than with big proprietary packages.

Communities including academics are used to free- hey how about paying say 1$ for each download.

There are two million R users- if say even 50 % of them  paid 1 $ as a lifetime license fee- you could sponsor enough new packages than twenty years of Google Summer of Code does right now.

Secondly, this pricing can easily be adjusted by shifting the licensing to say free for businesses less than 2 people (even for the enhanced corporate software version not just the plain vanilla community software thus further increasing the spread of the plain vanilla versions)- for businesses from 10 to 20 people offer a six month trial rather than one month trial.

– but adjust the pricing to much more realistic levels compared to competing software. Make enterprise software pay a real value.

That’s the only way to earn respect. as well as a few dollars more.

As for SAS, it is time it started ridiculing Python now that it has accepted R.

Python is even MORE powerful than R in some use cases for stat computing

Dixon’s Pentaho and the Jaspersoft/ Revolution combo are nice _ I tested both Jasper and Pentaho thanks to these remarks this week 🙂  (see slides at http://www.jaspersoft.com/sites/default/files/downloads/events/Analytics%20-Jaspersoft-SEP2010.pdf or http://www.revolutionanalytics.com/news-events/free-webinars/2010/deploying-r/index.php )

Pentaho and Jasper do give good great graphics in BI (Graphical display in BI is not a SAS forte though probably I dont know how much they cross sell JMP to BI customers- probably too much JMP is another division syndrome there)

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Using PostgreSQL and MySQL databases in R 2.12 for Windows

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If you use Windows for your stats computing and your data is in a database (probably true for almost all corporate business analysts) R 2.12 has provided a unique procedural hitch for you NO BINARIES for packages used till now to read from these databases.

The Readme notes of the release say-

Packages related to many database system must be linked to the exact
version of the database system the user has installed, hence it does
not make sense to provide binaries for packages
	RMySQL, ROracle, ROracleUI, RPostgreSQL
although it is possible to install such packages from sources by
	install.packages('packagename', type='source')
after reading the manual 'R Installation and Administration'.

So how to connect to Databases if the Windows Binary is not available-

So how to connect to PostgreSQL and MySQL databases.

For Postgres databases-

You can update your PostgreSQL databases here-

http://www.postgresql.org/download/windows

Fortunately the RpgSQL package is still available for PostgreSQL

  • Using the RpgSQL package

library(RpgSQL)

#creating a connection
con <- dbConnect(pgSQL(), user = "postgres", password = "XXXX",dbname="postgres")

#writing a table from a R Dataset
dbWriteTable(con, "BOD", BOD)

# table names are lower cased unless double quoted. Here we write a Select SQL query
dbGetQuery(con, 'select * from "BOD"')

#disconnecting the connection
dbDisconnect(con)

You can also use RODBC package for connecting to your PostgreSQL database but you need to configure your ODBC connections in

Windows Start Panel-

Settings-Control Panel-

Administrative Tools-Data Sources (ODBC)

You should probably see something like this screenshot.

Coming back to R and noting the name of my PostgreSQL DSN from above screenshot-( If not there just click on add-scroll to appropriate database -here PostgreSQL and click on Finish- add in the default values for your database or your own created database values-see screenshot for help with other configuring- and remember to click Test below to check if username and password are working, port is correct etc.

so once the DSN is probably setup in the ODBC (frightening terminology is part of databases)- you can go to R to connect using RODBC package


#loading RODBC

library(RODBC)

#creating a Database connection
# for username,password,database name and DSN name

chan=odbcConnect("PostgreSQL35W","postgres;Password=X;Database=postgres")

#to list all table names

sqlTables(chan)


TABLE_QUALIFIER TABLE_OWNER TABLE_NAME TABLE_TYPE REMARKS
1       postgres      public        bod      TABLE      
 2        postgres      public  database1      TABLE      
 3        postgres      public         tt      TABLE

Now for MySQL databases it is exactly the same code except we download and install the ODBC driver from http://www.mysql.com/downloads/connector/odbc/

and then we run the same configuring DSN as we did for postgreSQL.

After that we use RODBC in pretty much the same way except changing for the default username and password for MySQL and changing the DSN name for the previous step.

channel <- odbcConnect("mysql","jasperdb;Password=XXX;Database=Test")
test2=sqlQuery(channel,"select * from jiuser")
test2
 id  username tenantId   fullname emailAddress  password externallyDefined enabled previousPasswordChangeTime1  1   jasperadmin        1 Jasper Administrator           NA 349AFAADD5C5A2BD477309618DC              NA    01                       
2  2       joe1ser        1             Joe User           NA                 4DD8128D07A               NA    01
odbcClose(channel)
While using RODBC for all databases is a welcome step, perhaps the change release notes for Window Users of R may need to be more substantiative than one given for R 2.12.2
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Interesting R competition at Reddit

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Here is an interesting R competition going on at Reddit and it is to help Reddit make a recommendation engine 🙂

http://www.reddit.com/r/redditdev/comments/dtg4j/want_to_help_reddit_build_a_recommender_a_public/

by ketralnis

As promised, here is the big dump of voting information that you guys donated to research. Warning: this contains much geekery that may result in discomfort for the nerd-challenged.

I’m trying to use it to build a recommender, and I’ve got some preliminary source code. I’m looking for feedback on all of these steps, since I’m not experienced at machine learning.

Here’s what I’ve done

  • I dumped all of the raw data that we’ll need to generate the public dumps. The queries are the comments in the two .pig files and it took about 52 minutes to do the dump against production. The result of this raw dump looks like: 
    $ wc -l *.dump
 13,830,070 reddit_data_link.dump
136,650,300 reddit_linkvote.dump
     69,489 reddit_research_ids.dump
 13,831,374 reddit_thing_link.dump
  • I filtered the list of votes for the list of users that gave us permission to use their data. For the curious, that’s 67,059 users: 62,763 with “public votes” and 6,726 with “allow my data to be used for research”. I’d really like to see that second category significantly increased, and hopefully this project will be what does it. This filtering is done by srrecs_researchers.pig and took 83m55.335s on my laptop.
  • I converted data-dumps that were in our DB schema format to a more useable format using srrecs.pig(about 13min)
  • From that dump I mapped all of the account_ids, link_ids, and sr_ids to salted hashes (using obscure() insrrecs.py with a random seed, so even I don’t know it). This took about 13min on my laptop. The result of this, votes.dump is the file that is actually public. It is a tab-separated file consisting in: 
    account_id,link_id,sr_id,dir

    There are 23,091,688 votes from 43,976 users over 3,436,063 links in 11,675 reddits. (Interestingly these ~44k users represent almost 17% of our total votes). The dump is 2.2gb uncompressed, 375mb in bz2.

What to do with it

The recommendations system that I’m trying right now turns those votes into a set of affinities. That is, “67% of user #223’s votes on /r/reddit.com are upvotes and 52% on programming). To make these affinities (55m45.107s on my laptop):

 cat votes.dump | ./srrecs.py "affinities_m()" | sort -S200m | ./srrecs.py "affinities_r()" > affinities.dump

Then I turn the affinities into a sparse matrix representing N-dimensional co-ordinates in the vector space of affinities (scaled to -1..1 instead of 0..1), in the format used by R’s skmeans package (less than a minute on my laptop). Imagine that this matrix looks like

          reddit.com pics       programming horseporn  bacon
          ---------- ---------- ----------- ---------  -----
ketralnis -0.5       (no votes) +0.45       (no votes) +1.0
jedberg   (no votes) -0.25      +0.95       +1.0       -1.0
raldi     +0.75      +0.75      +0.7        (no votes) +1.0
...

We build it like:

# they were already grouped by account_id, so we don't have to
# sort. changes to the previous step will probably require this
# step to have to sort the affinities first
cat affinities.dump | ./srrecs.py "write_matrix('affinities.cm', 'affinities.clabel', 'affinities.rlabel')"

I pass that through an R program srrecs.r (if you don’t have R installed, you’ll need to install that, and the packageskmeans like install.packages('skmeans')). This program plots the users in this vector space finding clusters using a sperical kmeans clustering algorithm (on my laptop, takes about 10 minutes with 15 clusters and 16 minutes with 50 clusters, during which R sits at about 220mb of RAM)

# looks for the files created by write_matrix in the current directory
R -f ./srrecs.r

The output of the program is a generated list of cluster-IDs, corresponding in order to the order of user-IDs inaffinities.clabel. The numbers themselves are meaningless, but people in the same cluster ID have been clustered together.

Here are the files

These are torrents of bzip2-compressed files. If you can’t use the torrents for some reason it’s pretty trivial to figure out from the URL how to get to the files directly on S3, but please try the torrents first since it saves us a few bucks. It’s S3 seeding the torrents anyway, so it’s unlikely that direct-downloading is going to go any faster or be any easier.

  • votes.dump.bz2 — A tab-separated list of: 
    account_id, link_id, sr_id, direction
  • For your convenience, a tab-separated list of votes already reduced to percent-affinities affinities.dump.bz2, formatted: 
    account_id, sr_id, affinity (scaled 0..1)
  • For your convenience, affinities-matrix.tar.bz2 contains the R CLUTO format matrix files affinities.cm,affinities.clabel, affinities.rlabel

And the code

  • srrecs.pig, srrecs_researchers.pig — what I used to generate and format the dumps (you probably won’t need this)
  • mr_tools.py, srrecs.py — what I used to salt/hash the user information and generate the R CLUTO-format matrix files (you probably won’t need this unless you want different information in the matrix)
  • srrecs.r — the R-code to generate the clusters

Here’s what you can experiment with

  • The code isn’t nearly useable yet. We need to turn the generated clusters into an actual set of recommendations per cluster, preferably ordered by predicted match. We probably need to do some additional post-processing per user, too. (If they gave us an affinity of 0% to /r/askreddit, we shouldn’t recommend it, even if we predicted that the rest of their cluster would like it.)
  • We need a test suite to gauge the accuracy of the results of different approaches. This could be done by dividing the data-set in and using 80% for training and 20% to see if the predictions made by that 80% match.
  • We need to get the whole process to less than two hours, because that’s how often I want to run the recommender. It’s okay to use two or three machines to accomplish that and a lot of the steps can be done in parallel. That said we might just have to accept running it less often. It needs to run end-to-end with no user-intervention, failing gracefully on error
  • It would be handy to be able to idenfity the cluster of just a single user on-the-fly after generating the clusters in bulk
  • The results need to be hooked into the reddit UI. If you’re willing to dive into the codebase, this one will be important as soon as the rest of the process is working and has a lot of room for creativity
  • We need to find the sweet spot for the number of clusters to use. Put another way, how many different types of redditors do you think there are? This could best be done using the aforementioned test-suite and a good-old-fashioned binary search.

Some notes:

  • I’m not attached to doing this in R (I don’t even know much R, it just has a handy prebaked skmeans implementation). In fact I’m not attached to my methods here at all, I just want a good end-result.
  • This is my weekend fun project, so it’s likely to move very slowly if we don’t pick up enough participation here
  • The final version will run against the whole dataset, not just the public one. So even though I can’t release the whole dataset for privacy reasons, I can run your code and a test-suite against it

——————————————————————————————-

 

I am thinking of using Rattle and using the arules package, and running it on the EC2 to get the horsepower.

How else do you think you can tackle a recommendation engine problem.

 

Ajay

 

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