Monthly Archives: June, 2011

Rick Wicklin 5
Use subscript reduction operators!

Writing efficient SAS/IML programs is very important. One aspect to efficient SAS/IML programming is to avoid unnecessary DO loops. In my book, Statistical Programming with SAS/IML Software, I wrote (p. 80): One way to avoid writing unnecessary loops is to take full advantage of the subscript reduction operators for matrices.

Rick Wicklin 17
The trapezoidal rule of integration

In a previous article I discussed the situation where you have a sequence of (x,y) points and you want to find the area under the curve that is defined by those points. I pointed out that usually you need to use statistical modeling before it makes sense to compute the