It is common to want to extract the lower or upper triangular elements of a matrix. For example, if you have a correlation matrix, the lower triangular elements are the nontrivial correlations between variables in your data. As I've written before, you can use the VECH function to extract the
I received the following question: In the DATA step I always use the ** operator to raise a values to a power, like this: x**2. But on your blog I you use the ## operator to raise values to a power in SAS/IML programs. Does SAS/IML not support the **
I've been working on a new book about Simulating Data with SAS. In researching the chapter on simulation of multivariate data, I've noticed that the probability density function (PDF) of multivariate distributions is often specified in a matrix form. Consequently, the multivariate density can usually be computed by using the
