The DO Loop
Statistical programming in SAS with an emphasis on SAS/IML programs![A different way to interpret the negative binomial distribution](https://blogs.sas.com/content/iml/files/2014/04/negbin.png)
While at SAS Global Forum 2014 I attended a talk by Jorge G. Morel on the analysis of data with overdispersion. (His slides are available, along with a video of his presentation.) The Wikipedia defines overdispersion as "greater variability than expected from a simple model." For count data, the "simple
![SAS/IML available to all students through SAS Analytics U](https://blogs.sas.com/content/iml/files/2017/02/AdvancedAnalytics-3.png)
When spontaneous applause broke out during Dr. Jim Goodnight's presentation at the opening session of SAS Global Forum 2014, I was one of the people cheering the loudest. The SAS CEO had just announced free software for students and professors at universities around the world. The SAS University Edition will
![Define functions with optional parameters in SAS/IML](https://blogs.sas.com/content/iml/files/2014/03/optionalparams.png)
Last month I blogged about defining SAS/IML functions that have default parameter values. This language feature, which was introduced in SAS/IML 12.1, enables you to skip arguments when you call a user-defined function. The same technique enables you to define optional parameters. Inside the function, you can determine whether the
![Finding elements in one vector that are not in another vector](https://blogs.sas.com/content/iml/files/2014/03/t_element.png)
The SAS/IML language has several functions for finding the unions, intersections, and differences between sets. In fact, two of my favorite utility functions are the UNIQUE function, which returns the unique elements in a matrix, and the SETDIF function, which returns the elements that are in one vector and not
![For pi day: A continued fraction expansion of pi](https://blogs.sas.com/content/iml/files/2014/03/continuedfraction1.png)
Many geeky mathematical people celebrate "pi day" on March 14, because the date is written 3/14 in the US, which is evocative of the decimal representation of π = 3.14.... Most people are familiar with the decimal representation of π. The media occasionally reports on a new computational tour-de-force that
![How to get started with SAS: Free videos for beginners](https://blogs.sas.com/content/iml/files/2017/02/AdvancedAnalytics-4.png)
On most Mondays I blog about a function, programming technique, or resource that is useful for programmers who are getting started with SAS software. Recently I learned that my colleagues in the SAS education division have been hard at work developing a series of short videos that explain basic tasks