Conrad Sanderson released version 1.0.0 of Armadillo, his templated C++ library for linear algebra, earlier this week. So congratulations to Conrad on reaching 1.0.0! I folded his version 1.0.0 into a new release 0.2.10 of RcppArmadillo, our Rcpp-base... [Read more...]

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The increasing number of R-oriented Bayesian computational tools such as MCMCpack, MCMCglmm, DPpackage, R-INLA, spBayes, have made BUGS less and less crucial for day to day Bayesian computation. Honestly, I cannot figure out a single analysis that BUGS... [Read more...]

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With the distance matrix found in previous tutorial, we can use various techniques of cluster analysis for relationship discovery. For example, in the data set mtcars, we can run the distance matrix with hclust, and plot a dendrogram that displays a ... [Read more...]

Feature selection is the data mining process of selecting the variables from our data set that may have an impact on the outcome we are considering. For commercial data mining, which is often characterised by having too many variables for model building, this is an important step in the analysis ... [Read more...]

In connection with Le Monde puzzle #46, I eventually managed to write an R program that generates graphs with a given number n of nodes and a given number k of edges leaving each of those nodes. (My early attempt was simply too myopic to achieve any level of success when ... [Read more...]

Kaggle, the predictive-analytics competition site, has analyzed the preferences of the 2,500 data scientists who participate in its competitions, and R was the most-preferred software of the competitors at 22.5%. The next-nearest alternative was Matlab, at 16%. On a related note, the premier of the Australian state of New South Wales has just ... [Read more...]

Life is short, use PythonI started to play with Python two weeks ago due to the limitation of R in terms of handling large data, then a friend of mine suggested me to try Python since I had to do data massage frequently, "Python is the best choice, trust me", ... [Read more...]

Just read a funny but much to the point blog entry on the difficulties of teaching proper programming skills to first year students! I will certainly make use of the style file as grading 180 exams is indeed a recurrent nightmare… Filed under: R,... [Read more...]

Recently I found myself needing to calculate the distance between a large number of longitude and latitude locations. As it turns out, because the earth is a three-dimensional object, you cannot simply pretend that you are in Flatland, albeit some … Continue reading → [Read more...]

Principal component analysis (PCA) is a mathematical transformation of possibly(correlated) variables into a number of uncorrelated variables called principal components. The resulting components from this transformation is defined in such a way that t... [Read more...]

Here are the slides from the first University of Utah and Research Park R Users Group meeting. They discuss getting help and finding packages. R [Read more...]

Nathan Yau has just published at FlowingData a step-by-step guide on making bubble charts in R. It's actually pretty simple: read in data, sqrt-transform the "bubble" variable (to scale the bubbles by area, not radius), and use the symbols function to plot. It's the last step, though, that really ups ... [Read more...]

R and the NYC R User Group get brief mentions in this article about AOL's offices in New York City. The NYC UseRs meet at AOL and (ironically) the next meeting on Dec 9 is on the topic of R at Google. New York Observer: Bringing Some Sizzle to the Dial-Up ... [Read more...]

Each year I have the pleasure (actually it’s quite fun) of teaching R programming to first year mathematics and statistics students. The vast majority of these students have no experience of programming, yet think they are good with computers because they use facebook! The class has around 100 students, and ... [Read more...]

In this post we will make use of football results data from the football-data.co.uk website to demonstrate creating functions in R to automate a series of standard operations that would be required for results data from various leagues and divisions. The first step is to consider what control ... [Read more...]

Matti Vihola has posted a new paper on arXiv about adaptive (random walk) Metropolis-Hastings algorithms. The update in the (lower diagonal) scale matrix is where is the current acceptance probability and the target acceptance rate; is the current random noise for the proposal, ; is a step size sequence decaying to ... [Read more...]

One of the current best tools in the machine learning toolbox is the 1930s statistical technique called logistic regression. We explain how to add professional quality logistic regression to your analytic repertoire and describe a bit beyond that. A statistical analyst working on data tends to deliberately start simple move ... [Read more...]

This post provides a brief introduction to make and makefiles. In particular it describes how to set up make on Windows with an emphasis on using make in Eclipse on projects involving R, Sweave, and LaTeX. Overview make is software that uses makefile... [Read more...]