Rick Wicklin
Rick Wicklin RSS
Research Statistician Developer

Rick Wicklin, PhD, is a distinguished researcher in computational statistics at SAS and is a principal developer of PROC IML and SAS/IML Studio. His areas of expertise include computational statistics, statistical graphics, and modern methods in statistical data analysis. Rick is author of the books Statistical Programming with SAS/IML Software and Simulating Data with SAS. Follow @RickWicklin on Twitter.

Recent Posts

IF-THEN logic with matrix expressions

In the SAS DATA step, all variables are scalar quantities. Consequently, an IF-THEN/ELSE statement that evaluates a logical expression is unambiguous. For example, the following ... Read More

What is an empty matrix?

At the beginning of my book Statistical Programming with SAS/IML Software I give the following programming tip (p. 25): Do not confuse an empty matrix ... Read More

Finding matrix elements that satisfy a logical expression

A common task in SAS/IML programming is finding elements of a SAS/IML matrix that satisfy a logical expression. For example, you might need to know ... Read More

Calling a global statement inside a loop

The other day I was creating some histograms inside a loop in PROC IML. It was difficult for me to determine which histogram was associated ... Read More

Twelve posts from 2014 that deserve a second look

I began 2015 by compiling a list of popular articles from my blog in 2014. Although this "People's Choice" list contains many interesting articles, some ... Read More

Compute the kth smallest data value in SAS

A SAS programmer recently posted a question to the SAS/IML Support Community about how to compute the kth smallest value in a vector of numbers. ... Read More

Popular posts from The DO Loop in 2014

I published 118 blog posts in 2014. This article presents my most popular posts from 2014 and late 2013. 2014 will always be a special ... Read More

Self-similar structures from Kronecker products

I recently posted an article about self-similar structures that arise in Pascal's triangle. Did you know that the Kronecker product (or direct product) can be ... Read More

Elementwise minimum and maximum operators

Like most programming languages, the SAS/IML language has many functions. However, the SAS/IML language also has quite a few operators. Operators can act on a ... Read More

A Christmas tree from Pascal's triangle

O Christmas tree, O Christmas tree, One year a fractal made thee! O Christmas tree, O Christmas tree, A heat map can display thee! From ... Read More