I guess I've been living in a bubble for a bit, but apparently there are a lot of people who still mistrust R. I got asked this week why I used R (and, specifically, the package rpart) to generate classification and regression trees instead of SAS Ente... [Read more...]

I work in an environment dominated by SAS, and I am looking to integrate R into our environment. Why would I want to do such a thing? First, I do not want to get rid of SAS. That would not only take away most of our investment in SAS training ... [Read more...]

Let’s say you are in the middle of a salary negotiation, and you want to know whether you should be aggressive in your offering or conservative. One way to help with the decision is to make a decision tree. We’ll work with the following assumptions: You are at ... [Read more...]

Many statistical algorithms are taught and implemented in terms of linear algebra. Statistical packages often borrow heavily from optimized linear algebra libraries such as LINPACK, LAPACK, or BLAS. When implementing these algorithms in systems such as Octave or MATLAB, it is up to you to translate the data from the ... [Read more...]

In a previous post (a long time ago) I discussed a way to get a R data frame into a Word table. The code in that entry was essentially a brute force way of wrapping R data in RTF code, but that RTF code was the bare minimum. There was ... [Read more...]

I think I have found a superior solution to integrating Ultraedit and R. See my post over at IDM Users forum. [Read more...]

My favorite text editor on Windows is Ultraedit, but it does not have a nice interface to R in the same vein as Emacs/ESS, Tinn-R, or Eclipse. (I have never used Eclipse.) Ultraedit is powerful enough to submit whole R programs... [Read more...]

Well, I'm taking the plunge and learning Python. We'll see how this goes. Then I'll try NumPy (and SciPy, if it gets ported), and see of I can get R and Python talking. [Read more...]

I usually like AnnMaria's witty insight. I can relate to a lot of what she is saying. After all SAS and family life are large parts of my life, too. But you can imagine the reaction she provoked in saying the following:I know that R is free and I ... [Read more...]

I've been working on this for quite some time (see here for a little background), so I'm pleased that it looks close to done at least as far as the core algorithm. It uses global variables for now, and I'm sure there are a couple of other bugs lurking, but ... [Read more...]

In order to move some of my personal interests along, I have been trying to implement the methodology found in Berry and Berry's article Accounting for Multiplicities in Assessing Drug Safety. This methodology uses the MedDRA hierarchy to improve the p... [Read more...]

I've been following the discussion on causal inference over at Gelman's blog with quite a bit of interest. Of course, this is in response to Judea Pearl's latest book on causal inference, which differs quite a bit from the theory that had been forwarde... [Read more...]

Last time I used an HTML solution. This time, I create an RTF file:# function: my.rtf.table# purpose: convert a matrix, data.frame, or array into a rtf table# output: text for RTF, possibly written to a file# inputs:# tab - a table, dataframe, or array (needs rownames and ... [Read more...]

As I use R more in consulting, I'm finding the need to make the quick transition from R to Microsoft products (usually Word) more serious. (I'm using a Windows platform, but I'm sure the challenges on the Mac would be similar.) I simply don't have time to do the text ... [Read more...]

Jim Albert has a blog based on his book Bayesian Computation in R. Unfortunately, it seems they haven't been updating it too much recently but it looks like what's there is pretty good. [Read more...]

RKN over at Epidemiology blog had a small problem he solved using simulation:I have been interested in the following question: if there are, let's say, 5 genes involved in the liability of fx risk, and each gene has two alleles with one of them conferr... [Read more...]

When I first read Andrew Gelman's quick off-the-cuff review of the book Bayesian Computation with R, I thought it was a bit harsh. So did Gelman.I thumbed through the book at the joint statistical meetings, and decided to buy it along with Bayesian Cor... [Read more...]

From time to time, I'll complain about the weirdness of SAS, the statistical analysis program of choice for much of the pharmaceutical industry. This post is one such complaint.Why, oh why, does SAS not directly give us the asymptotic variance of the M... [Read more...]