I am writing way too many posts in a row on Google tools. I promise I will think about something else soon. I find amusing the possibility to launch a search in Google images by just dragging a picture into … Continue reading →

If you've used SAS or SPSS and want a jump-start into the basics of the popular R language, next week's webinar, Introduction to R for SAS and SPSS Users will be of interest to you. While R, SAS and SPSS are all three software systems for data analysis and graphics, the underlying concepts in R are quite different to...

To follow on from the earlier post on using R through Java, it is even easier to get jri up and running as a NetBeans module. Why is this useful? Well the platform that the NetBeans IDE is built on … Continue reading →

The R Graph Gallery, the website from Romain François that showcases hundreds of examples of data visualization with R, has new social features. Now, when you find a graph or chart you find appealing or useful, you can "Like" it on Facebook or "+1" it on Google+. This should be a great way of highlighting the best charts and...

In response to my last post, “The Long Tail of the Pareto Distribution,” Neil Gunther had the following comment: “Unfortunately, you've fallen into the trap of using the ‘long tail’ misnomer. If you think about it, it can't possibly be the length of the tail that sets distributions like Pareto and Zipf apart; even the negative exponential and Gaussian...

Just what is Data Science, anyway? Here's one take: Ever since the term "Data Scientist" was coined by DJ Patil and Jeff Hammerbacker in 2009, there's been a vigorous debate on what the team actually means. More than 80% of statisticians consider themselves data scientists, but Data Science is more than just Statistics. (My own take is that Data...

While reading UseR conference abstracts I came across this sentence: "Sugarcane is polypoid, i.e., has 8 to 14 copies of every chromosome, with individual alleles in varying numbers." Vau! This generates really complex genotype system. Say we have biallelic gene with alleles being A and B. In diploids the possible genotypes are AA, AB, and BB. Given the...

Pierre Pudlo and I worked this morning on a distribution related to philogenic trees and got stuck on the following Bessel integral where In is the modified Bessel function of the first kind. We could not find better than formula 6.611(4) in Gradshteyn and Ryzhik. which is for a=0… Anyone in for a closed form

Looks like there's been a lot of activity in the R user community in the Northern hemisphere now that the summer break is over. I've just added several new groups to the Local R User Group Directory: Tokyo, Japan: The Tokyo.R R study group has already had 17 meetings, but has just been added to the directory. Shanghai/East China:...

The pgf drawing package for LaTeX provides facilities for drawing simple of complicated pictures within a LaTeX document. There are many options available within the package and in this post we consider some of the basics to get up and running. Fast Tube by Casper As with all LaTeX documents we need to select a

fMRI data from 90 locations in the brain look somewhat like daily closing prices on 116 stocks if you squint just right. Marginal Revolution was nice enough to point to “Topological isomorphisms of human brain and financial market networks”. I’ve only just glanced through the paper. I find it interesting, but I’m fairly skeptical. The … Continue reading...

Revolution Analytics today announced that it has partnered with Cloudera, the leader in Apache Hadoop-based software and services, to make big-data analytics with Hadoop and R available to Revolution R Enterprise users. As we announced earlier this month, we have created three open-source R packages which make it possible for R users to write map-reduce programs in the R...

Although this was only a half-day of talks, the third day of the workshop was equally thought-challenging and diverse. (I managed to miss the ten first minutes by taking a Line 3 train to 125th street, having overlooked the earlier split from Line 1… Crossing south Harlem on a Sunday morning is a fairly mild

I discuss how to use Inkscape to easily shift around labels on graphs produced in R. Continue reading →

Barry Rowlingson gave an interesting talk at UseR 2011, “Why R-help must die!” He suggested the Q-and-A type sites Stack Overflow (on programming) and Cross Validated (on statistics), both part of Stack Exchange. An interesting feature of these sites is that, in addition to voting up and down on the questions and answers, one accrues

Teacher: “How variable is your estimate of the mean?” Student: “Uhhh, it’s not. I took a sample and calculated the sample mean. I only have one number.” Teacher: “Yes, but what is the standard deviation of sample means?” Student: “What do you mean means, I only have the one friggin number.” Statisticians have a habit