A Pareto chart, named after Vilfredo Pareto, is a type of chart that contains both bars and a line graph, where individual values are represented in descending order by bars, and the cumulative total is represented by the line (quoted from Wikipedia). ... [Read more...]

Two papers got published recently. The first one is Bates and Eddelbuettel (2013). It is titled Fast and Elegant Numerical Linear Algebra Using the RcppEigen Package, and provides a pretty thorough introduction to our RcppEigen package which uses Rcpp to provide access to the Eigen C++ template library from GNU R. ... [Read more...]

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Useful Resources to Learn about R on the Internet When I program in R and struggle with something, the first thing that I usually turn to is Google.  I search the relevant function or the desired outcome, and I often find the solutions within the first few hits.  They likely ... [Read more...]

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In this tutorial you will learn: what is a heatmap how to create a clean, highly customizable heatmap using heatmap.2 in the gplots package in R how to remove samples with poor output (not very many sequences) how to rearrange your samples by a metadata category how to make a ... [Read more...]

A new book by Jeffrey Stanton from Syracuse Iniversity School of Information Studies, An Introduction to Data Science, is now available for free download. The book, developed for Syracuse's Certificate for Data Science, is available under a Creative Commons License as a PDF (20Mb) or as an interactive eBook from ... [Read more...]

Had a great time earlier this week on a Google Hangout as part of the IBM Opinionated Infrastructure series. Moderator James Governor (analyst from RedMonk) kept the conversation lively, with topics ranging from to the value of information to the benefits of predictive analytics and evolution of Hadoop. R gets ... [Read more...]

Preface I will every now and then post my experience with R, a package for statistical analyses. I try to show some solutions for common types of analyses or problems you are facing when you start working with R. These … Weiterlesen → [Read more...]

Using correlation to track model performance is “a mistake that nobody would ever make” combined with a vague “what would be wrong if I did do that” feeling. I hope after reading this feel a least a small urge to double check your work and presentations to make sure you ... [Read more...]

  My daughter, who turns 10 in April, has discovered pop music. She’s been listing to Virgin Radio 99.9, one of our local stations. Virgin provides an online playlist that goes back four days, so I scraped the data and brought it into R. The chart shown at top shows all of ... [Read more...]

As I am working with large gene expression matrices (microarray data) in my job, it is sometimes important to look at the correlation in gene expression of different genes. It has been shown that by calculating the Pearson correlation between genes, one can identify (by high values, i.e. __ 0.9) genes ... [Read more...]

 Embarrassingly I'm stumped on this...I have a program in R for looking at grade distributions in my class. I found something weird recently with my 'ifelse' processing. I noticed that my program seemed to be over counting Cs and under counting... [Read more...]

Note to R users: Users of other languages enjoy spending lots of time discussing the minutiae of the language they use, something R users don’t appear to do; perhaps you spend your minutiae time on statistics which I don’t yet know well enough to spot when it occurs). ... [Read more...]

Knitr is a great tool for doing reproducible research. You can produce all kinds of output inside a single knitr chunk, e.g. you can write a loop to produce lots of figures or tables. The only catch is if you want your figures to have differing captions, heights, etc (... [Read more...]

Here are three recent news articles that feature interviews with members of the Revolution Analytics team talking about the importance of the R language: In Forbes, CEO Dave Rich talks to Gil Press about the business landscape for Big Data. In the article, Dave says: SAS and SPSS remind me ... [Read more...]

I cringe when I see research proposals that describe a sophisticated statistical approach, yet do not evaluate this approach in their power/precision/sample size planning. It's often the case that a simplified version of the proposed statistical approach is used instead. Presumably, this is due to the limited availability ... [Read more...]

The Cauchy distribution (?dcauchy in R) nails a flashlight over the number line and swings it at a constant speed from 9 o’clock down to 6 o’clock over to 3 o’clock. (Or the other direction, from 3→6→9.) Then counts how much light shone on each number. In other words we want ... [Read more...]

When I want to insert figures generated in R into a LaTeX document, it looks better if I first remove the white space around the figure. Unfortunately, R does not make this easy as the graphs are generated to look good on a screen, not in a document. There are ... [Read more...]

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