## R again in Google Summer of Code

March 22, 2011
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I'm a big fan of the Google Summer of Code.  It brings great projects together with a learning opportunity for students.  Once again the R Project was selected to be part of the Google Summer of Code in 2011.  Some other notable mathemat...

## Where the heck has JD been?

March 22, 2011
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It’s been pointed out to me that I haven’t had any blog posts in a while. It’s true. I’m fairly slack. But in the last few months I’ve changed jobs (same firm, new role), written an R abstraction on top of Hadoop, been to China, and managed to stay married. While that sounds pretty awesome,

## Code: extended model support for mtable

March 22, 2011
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$Code: extended model support for mtable$

I finally got around to organizing and packaging my complete set of extended model support for mtable in Martin Elff’s memisc library. Here is a list of the models supported: coxph, survreg – Cox proportional hazards models and parametric survival … Continue reading →

## More on R-Studio

March 22, 2011
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Here's a link to keyboard shortcuts for the RStudio IDE. RStudio has replaced EMacs, Aquamacs, Tinn-R, Bluefish, and even Komodo Edit as my preferred R IDE/editor.http://gettinggeneticsdone.blogspot.com/2011/03/rstudio-keyboard-shortcut-reference-pdf.h...

## Analysis: R growth continues in popularity of data analysis software

March 22, 2011
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Bob Muenchen, author of R for SAS and SPSS Users and co-author of R for Stata Users, has updated his in-depth analysis of the popularity of data analysis software. Determining "popularity" for software is a tricky task, but this analysis looks at several different metrics: mailing list traffic, blogs, search volumes, job listings and other such indirect methods, as...

## One bicycle for two

March 22, 2011
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$One bicycle for two$

Robin showed me a mathematical puzzle today that reminded me of a story my grand-father used to tell. When he was young, he and his cousin were working in the same place and on Sundays they used to visit my great-grand-mother in another village. However, they only had one bicycle between them, so they would

## Free and Easy Currency Monitor in R

March 22, 2011
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Certainly not the best way to keep up with currencies, but the increasingly important job of monitoring currencies can be free and easy in R using Federal Reserve FRED data.  Here is a template that can be adjusted to your favorite currencies with...

## A Short Side-by-side Comparison of the R and NumPy Array Types

March 22, 2011
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Feature NumPy R contiguous (virtual) memory ✔ ✔ 'view' memory model ✔ ✘ subset-assignment ✔ ✔ vectorized operations ✔ ✔ memory-mapping ✔ ✘* broadcasting rules ✔ ✔ index arrays ✔ ✔ This comparison is current as of R 2.13.0, NumPy version 1.4.1, and other web resources to date. Because this post was motivated by a

## Visualizing Missing Data

March 22, 2011
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There are several graphics available for visualizing missing data. The following graphic was inspired by many sources. However, I wanted a version using ggplot2. What is visualized here is the percent missing for each variable in the PISA data across countries. The code will be available as part of the multilevelPSA package I am currently

## Comparison of UAH and GISS Time Series with Common Baseline

March 22, 2011
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In this post I set both UAH and GISS global temperature anomaly series to a common baseline period (1981-2010)  and compare them. Even though the UAH series is satellite based and GISS series is station based, the series exhibit striking … Continue reading →

## data.table: an R package everyone should use

March 22, 2011
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I’m not sure how I missed this package, but I am sure glad I’ve found it. The data.table package for R provides something of a reconceptualization of the standard data.frame object. Though it remains (mostly) compatible with data.frame. The advantage … Continue reading →

## Correlation network

March 22, 2011
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I came up with an idea to draw correlation network to get a grasp about relationship between a list of stocks. An alternative way to show correlation matrix would be head map, which can have limitations with big matrices (>100). Unfortunately,  ggplot2 package doesn’t have a easy way to draw the networks, so I was left

## Example 8.31: Choropleth maps

March 22, 2011
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In our book, we show a simple example of a map (section 6.4.2) where we read the boundary files as data sets and use SAS and R to plot them. But both SAS and R have complex functionality for using pre-compiled map data. To demonstrate them, we'll sho...

## Machine Learning Ex2 – Linear Regression

March 22, 2011
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Thanks to this post, I found OpenClassroom. In addition, thanks to Andrew Ng and his lectures, I took my first course in machine learning. These videos are quite easy to follow. Exercise 2 requires implementing gradient descent algorithm to model data with linear regression. Read More: 243 Words Totally

## JCGS 20th anniversary

March 22, 2011
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For its 20th anniversary, JCGS offers free access to papers, including Andrew’s discussion paper Why tables are really much better than graphs. (Another serious ending for an April fool joke!) Incidentally (or rather coincidentally), I received today the great news that our Using parallel computation to improve Independent Metropolis-Hastings based estimation paper is accepted by

## Day #9 Using R in Knime nodes

March 22, 2011
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First you need to create a workflow in Knime. This is what i used. I loaded in the Iris data, renamed the tables for further use in my scripts and showed a view, or first did an R snippet to show a view afterwards. Once this is done, make sure your R-B...

## Using R for Introductory Statistics 6, Simulations

March 21, 2011
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R can easily generate random samples from a whole library of probability distributions. We might want to do this to gain insight into the distribution's shape and properties. A tricky aspect of statistics is that results like the central limit theorem come with caveats, such as "...for sufficiently large n...". Getting a feel for how...

## Using R for Introductory Statistics 6, Simulations

March 21, 2011
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R can easily generate random samples from a whole library of probability distributions. We might want to do this to gain insight into the distribution's shape and properties. A tricky aspect of statistics is that results like the central limit theore...

## Statistics forum

March 21, 2011
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The ASA is launching a new blog called the Statistics Forum, managed by Andrew Gelman and to which I will periodically contribute items that may induce some amount of discussion within the community, like the first entry by Michael Lavine on testing. (Meaning I will double-post on the Og and on the Statistics Forum, if

## A 3D Version of R’s curve() Function

March 21, 2011
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I like exploring the behavior of functions of a single variable using the curve() function in R. One thing that seems to be missing from R’s base functions is a tool for exploring functions of two variables. I asked for examples of such a function on Twitter today and didn’t get any answers, so I

## Updated infochimps R package, includes several new APIs

March 21, 2011
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Recently, the good folks at Infochimps.com rolled out a series of new APIs to add to their already impressive set of data resources. I have been in a perpetual state of catch-up since the new year, so I have only now got around to adding some of these new APIs to the infochimps R package. Here

## Code Highlighter for R in WordPress

March 21, 2011
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First of all, welcome to my blog! I will write posts about trading, quantitative and algorithmic trading, programming and everything else what is on my mind. Feel free to comment and give suggestions how to improve this blog. Thank you! Well, one of th...

## RStudio Keyboard Shortcut Reference PDF

March 21, 2011
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I recently started using RStudio, the amazing new IDE for R. You can view all of RStudio's keyboard shortcuts by going to the help menu, but I made this printable reference for myself and thought I'd share it. I only included the Windows shortcuts, and...

## RStudio Keyboard Shortcut Reference PDF

March 21, 2011
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I recently started using RStudio, the amazing new IDE for R. You can view all of RStudio's keyboard shortcuts by going to the help menu, but I made this printable reference for myself and thought I'd share it. I only included the Windows shortcuts, and...

## NBA Analysis: Coming Soon!

March 21, 2011
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I decided to spend a few hours this weekend writing the R code to scrape the individual statistics of NBA players (2010-11 only).  I originally planned to write up a few NBA-related analyses, but a friend was visiting from out … Continue reading →

## Day #8 Calling R in java

March 21, 2011
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What is JRI? An additional library and plugin for Eclipse to call r functions in a Java-application. And according to wikipedia it’s  a now obsolete API for invoking native C++ calls from Java that has long been supplanted by Java Native Interfa...

## Looking at the "Curse of Dimensionality" with R, foreach, and lattice

March 20, 2011
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Here are the results of a "Curse of Dimensionality" homework assignment for Terran Lane's Introduction to Machine Learning class. Pretty pictures, interesting results, and a good exercise in explicit parallelism with R. It's neat to see distance scaling linearly with standard deviation, and linearly with the Lth-root...

## Fast(ish) extraction of exon locations from a BED12 file using data.table

March 20, 2011
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Here is a fast R function to extract exon locations from a BED12 file. Note that fast is a relative term, the function below is fast enough for me, may not be fast enough for others :) Anyway, a BED12 file typically has locations of genomic features (t...