When I studied math in school, I learned that the expression a (mod n) is always an integer between 0 and q – 1 for integer values of a and q. It's a nice convention, but SAS and many other computer languages allow the result to be negative if a (or q) is
The SAS/IML language supports user-defined functions (also called modules). Many SAS/IML programmers know that you can use the RETURN function to return a value from a user-defined function. For example, the following function returns the sum of each column of matrix: proc iml; start ColSum(M); return( M[+, ] ); /*
Sometimes a small option can make a big difference. Last week I thought to myself, "I wish there were an option that prevents variable labels from appearing in a table or graph." Well, it turns out that there is! I was using PROC MEANS to display some summary statistics, and
