An R tip: Did you know that x] is the same as x]]? I should make more thorough use of this. In the help file for ] is equivalent to alist]...] providing all but

I briefly investigated how to draw curved arrows in R. Here’s a small piece of the figure that I ultimately created: A google search for “curved arrows in R” revealed three options: curvedarrow in the diagram package The internal function igraph.Arrows within the igraph package (mentioned by Gabor Csardi in R help) Using xspline for

Graduate students in statistics often take (or at least have the opportunity to take) a statistical computing course, but often such courses are focused on methods (like numerical linear algebra, the EM algorithm, and MCMC) and not on actual coding. For example, here’s a course in “advanced statistical computing” that I taught at Johns Hopkins

Rainer pointed out, in response to my post, Row names in data frames: Beware of 1:nrow, that if I’d used rownames(x) <- as.character(1:3) rather than rownames(x) <- 1:3, I wouldn’t have had the problem I’d seen. If you type rownames(x) you see the same result as rownames(z), and is.character(rownames(x)) and is.character(rownames(z)) both return TRUE, but

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