Monthly Archives: April 2011

Using rApache for Web Services

April 5, 2011
By

Ran across a technical report I wrote in April 2009 regarding my work linking REDCap with rApache. Here’s the introductory text and a link to the original report (note that way back then I was calling it Rapache - now it’s rApache - don’t ask): ...

Read more »

Rcpp 0.9.3

April 5, 2011
By

A brand new and shiny 0.9.3 release of Rcpp is now on CRAN and Debian.This version contains an actual bug fix for Rcpp modules and a few build improvements, including for both clang/llvm and g++-4.6 (which, being in Debian, is already used for c...

Read more »

Example 8.33: Merging data sets one-to-many

April 5, 2011
By
Example 8.33: Merging data sets one-to-many

It's often necessary to combine data from two data sets for further analysis. Such merging can be one-to-one, many-to-one, and many-to-many. The most common form is the one-to-one match, which we cover in section 1.5.7. Today we look at a one-to-man...

Read more »

How to: Multinomial regression models in R

April 5, 2011
By
How to: Multinomial regression models in R

Apples, oranges, pears or bananas? Bus, train, car, or walk? Many choices are made between more than two options, a situation that can be represented by multinomial choice modelling. Here's a quick tutorial on how to do it in R.

Read more »

Painting a picture of statistical packages

April 4, 2011
By
Painting a picture of statistical packages

Imagine you have to analyze text comprising 18,000 words. You have to identify the most commonly cited ideas or words in the text and then present the analysis in a graphic format. There are sophisticated tools out there to help you with this task, but then again there is a tight deadline. You have fewer than five minutes to...

Read more »

Painting a picture of statistical packages

April 4, 2011
By
Painting a picture of statistical packages

Imagine you have to analyze text comprising 18,000 words. You have to identify the most commonly cited ideas or words in the text and then present the analysis in a graphic format. There are sophisticated tools out there to help you with this task, but then again there is a tight deadline. You have fewer than five minutes to...

Read more »

R 101: Vectors

Vectors are a basic data structure in R and are created using the c() function. Unlike data frames and lists, the elements of a vector must be of the same mode. Functions can be used on a vector. For example, length(x) can be used to find the number of elements in x. Furthermore, conditions can

Read more »

Book: ggplot2 by Hadley Wickham

April 4, 2011
By
Book: ggplot2 by Hadley Wickham

All my recent plots are built using ggplot2 package. I don’t know if my dear readers have noticed the difference, but from my point of view, ggplot2 allows to create nice looking and aesthetics plots. I was using this package before, but the real boost came after reading this book: ggplot2: Elegant Graphics for Data Analysis (Use R).

Read more »

Comparison of compression

April 4, 2011
By
Comparison of compression

I recently wrote an email with an attached LZMA archive. It was immediately answered with something like:"What are you doing? I had to boot linux to open the file!"First of all I don't care whether user of proprietary systems are able to read open formats, but this answer made me curious to know about the differences between some compression...

Read more »

RQuantLib Windows binary on CRAN

April 4, 2011
By

Dirk Eddelbuettel has recently released RQuantLib-0.3.7, which contains the necessary QuantLib builds to allow the CRAN servers to build the Windows binary.This (thankfully) makes my post on how to build RQuantLib on 32-bit Windows unnecessary for casu...

Read more »