I posted some notes this evening on working with probability distributions in Mathematica and R/S-PLUS.

I much prefer Mathematica’s syntax. The first time I had to read some R code I ran across a statement something like `runif(1, 3, 4)`

. I thought it was some sort of conditional execution statement: run something if some condition holds. No, the code generates a random value uniformly from the interval (3, 4). The corresponding Mathematica syntax is `Random[ UniformDistribution[3,4] ]`

.

Another example. The statement `pnorm(x, m, s)`

in R corresponds to `PDF[ NormalDistribution[m, s], x ]`

in Mathematica. Both evaluate the PDF of a normal random variable with mean m and standard deviation s at the point x.

It’s a matter of taste. Some people prefer terse notation, especially for things they use frequently. I’d rather type more and remember less.

Mathematica 8

pnorm = PDF[NormalDistribution[m, s], x ]