For those interested in **how pseudo random number generators work**, I just wrote something on Statalist which you can see in the Statalist archives by clicking the link even if you do not subscribe:

**http://www.stata.com/statalist/archive/2012-10/msg01129.html**

To remind you, I’ve been writing about how to *use* random-number generators in parts **1**, **2**, and **3**, and I still have one more posting I want to write on the subject. What I just wrote on Statalist, however, is about how random-number generators work, and I think you will find it interesting.

To find out more about Statalist, see

**Statalist**

**How to successfully ask a question on Statalist**

I want to start a series on using Stata’s random-number function. Stata in fact has ten random-number functions: Read more…

Last time, I showed you a way to graph and to think about matrices. This time, I want to apply the technique to eigenvalues and eigenvectors. The point is to give you a picture that will guide your intuition, just as it was previously.

Before I go on, several people asked after reading part 1 for the code I used to generate the graphs. Here it is, both for part 1 and part 2: matrixcode.zip. Read more…

I want to show you a way of picturing and thinking about matrices. The topic for today is the square matrix, which we will call **A**. I’m going to show you a way of graphing square matrices, although we will have to limit ourselves to the 2 *x* 2 case. That will be, as they say, without loss of generality. The technique I’m about to show you could be used with 3 *x* 3 matrices if you had a better 3-dimensional monitor, and as will be revealed, it could be used on 3 *x* 2 and 2 *x* 3 matrices, too. If you had more imagination, we could use the technique on 4 *x* 4, 5 *x* 5, and even higher-dimensional matrices. Read more…