R posts in other languages
The Department of methodology and Evaluation Research at Universität Jena has made available a set of free online video courses on data analysis.They cover topics that are particularly relevant to psychology and social science researchers, including ...
Click on image for a larger version. Here is the code: par(bg="black") par(mar=c(0,0,0,0)) plot(sort(rpois(10000,100))/rpois(10000,100),frame.plot=F,pch=20,col="blue")
This is one way to check for the version of PGF that is installed in an automated way. First create a tex file with the following contents: \documentclass{article} \usepackage{tikz} \batchmode \makeatletter \typeout{PGFVersion=\pgfversion} \@@end Say you named it test-pgf-version.tex. Then: pdflatex test-pgf-version.tex cat test-pgf-verson.log | grep PGFVersion | sed ‘s/PGFVersion=//’ should display the version number. I
I had the great pleasure of sitting down for a beer with Steve O'Grady (from the open-source analyst group RedMonk), at the MySQL conference last week. It was great to get the perspective of someone who knows the tech industry so well, sees predictive analytics as a hot area, and is taking an active interest in statistics and R...
Lately I’ve been writing maximum likelihood estimation code by hand for some economic models that I’m working with. It’s actually a fairly simple task, so I thought that I would write up the basic approach in case there are readers who haven’t built a generic estimation system before. First, let’s start with a toy example
Parallel Processing backend for R under windows - installation tips and some examples.
Networks – social and biological – are all the rage, just now. Indeed, a recent entry at Duncan’s QOTD described the “hairball” network representation as the dominant cultural icon in molecular biology. I’ve not had occasion to explore networks “professionally”, but have always been fascinated by both networks and the tools used to analyse them. 
Last Friday and Saturday the second R / Finance conference took place in Chicago on the UIC campus. As a co-organizer, it was a great pleasure to see so many users of R in Finance---from both industry and academia---come to Chicago to discuss and sh...
Last Friday and Saturday the second R / Finance conference took place in Chicago on the UIC campus. As a co-organizer, it was a great pleasure to see so many users of R in Finance---from both industry and academia---come to Chicago to discuss and shar...
Last Friday and Saturday the second R / Finance conference took place in Chicago on the UIC campus. As a co-organizer, it was a great pleasure to see so many users of R in Finance---from both industry and academia---come to Chicago to discuss and sh...
Order this book from Amazon This book is written by the author of the ggplot2 package for R, which is a package with a design inspired by the grammar of graphics and can remove some of the effort required to put together impressive graphs. The book is just under 200 pages and covers a
The R tag on StackOverflow recently topped 1000 questions, and continues to be a great community resource for practical tips on using the R language for data analysis and visualization. To take one example, "Efficiency of operations on R data structures" has been answered with some great tips on efficiently getting data in and out of the R system....
This RClimate Script lets users retrieve and plot the monthly and moving average Pacific Decadal Oscillation (PDO) data from the University of Washington’s JISAO website. The script retrieves the PDO data from January, 1900 until latest month available at time … Continue reading 
I've been travelling for the past few days (for the R/Finance 2010 conference in Chicago), so I'd missed much of the reaction to AnnMaria De Mars' article last week where she claimed that "R is an epic fail". Understandably, that inflammatory statement provoked many reactions from the R community on Twitter and in the blogosphere. (I suspect the fact...
In the following post, I'll create a C extension for R. This extension will iterate over all the FASTA sequences in a file and will return a pair(name,sequence) for each sequence, that is to say that I won't store all the sequences in memory.The C code...
In the following post, I'll create a C extension for R. This extension will iterate over all the FASTA sequences in a file and will return a pair(name,sequence) for each sequence, that is to say that I won't store all the sequences in memory.The C code...
Just read about a new R package called alphahull (paper) that sounds like it might be a good candidate for addressing this request regarding concave hulls. Below are some notes on computing alpha-shapes and alpha-hulls from spatial data and converting the results returned by ashape() and ahull() into SP-class objects. Note that the functions...
Confidence intervals and prediction intervals are used by statisticians on a regular basis. Another useful interval is the tolerance interval that describes the range of values for a distribution with confidence limits calculated to a particular percentile of the distribution. The R package tolerance can be used to create a variety of tolerance intervals of
Missing Data
Soil scientists routinely sample, characterize, and summarize patterns in soil properties in space, with depth, and through time. Invariably, some samples will be lost or sufficient funds required for complete characterization can run out. In these cases the scientist is left with a data table that contains holes (so to speak) in the rows/columns that are...
R can be annoying in that even if you stretch your terminal or R GUI session to a whole screen width it will still only show 80 characters width. This can make wide tables really hard to read. options(width=150)Use the options command width to set...
R can be annoying in that even if you stretch your terminal or R GUI session to a whole screen width it will still only show 80 characters width. This can make wide tables really hard to read. options(width=150)Use the options command width to set...
For interactive data analysis, the default fonts used by SAS and R are acceptable, if not beautiful. However, for publication, it may be important to manipulate the fonts. For example, it would be desirable for the fonts in legends, axis labels, or o...
Here’s the situation. Web applications, built using a framework (e.g. Rails, Django) are great for fetching data from a database and rendering it. They’re not so great for crunching and charting the data. Conversely, R is great for crunching and charting, but doesn’t make for a great web application. The idea then, is to let 
I just got back from R/Finance 2010 in Chicago. If you couldn't make it this year, I strongly encourage you to attend next year. I will post a more comprehensive review of the event in the next couple days, but I wanted to share some of my notes spec...
Darren Wraith pointed out this column about sudokus to me. It analyses the paper by Newton and De Salvo published in the Proceedings of the Royal Academy of Sciences A that I cannot access from home. The discussion contains this absurd sentence “Sudoku matrices are actually more random than randomly-generated matrices” which shows how mistreated 
A scatter plot is a graph used to investigate the relationship between two variables in a data set. The x and y axes are used for the values of the two variables and a symbol on the graph represents the combination for each pair of values in the data set. This type of graph is
new paper on the α-convex hull appeared in the Journal of Statistical Software today (http://www.jstatsoft.org/v34/i05/paper). The α-convex hull is an interesting problem which caught my attention long time ago but I didn’t know a solution then. R has a function chull() which can generate (indices of) the convex hull for a series of points. Now
This is a follow-on to my previous post about determining significant digits, or sigdigs, in performance and capacity planning calculations. Once we know how to do that, inevitably we will be faced with rounding the result of a calculation to the least...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
