Rick Wicklin, PhD, is a distinguished researcher in computational statistics at SAS and is a principal developer of SAS/IML software. His areas of expertise include computational statistics, simulation, 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.
A frequently performed task in data analysis is identifying all the observations in a data set that satisfy certain conditions. For example, you might want to identify all of the female patients in your study or to identify all patients whose systolic blood pressure is greater than 140 mm Hg.
"How do I apply a format to a vector of values in IML? In the DATA step, I can just call the PUTN function.” This question came from a SAS customer that I met recently at a conference. My reply? Use the PUTN function, but send it a vector of
The R You Ready blog posed an interesting problem. Essentially, you have a vector that contains n(n+1)/2 elements, and you want to pack those elements into the upper left triangular portion of a matrix. For example, if your data are proc iml; /** vector v is given: ncol(v) = n(n+1)/2 for
When programmers begin learning a new computer language, the first program they write is often one that prints the text “Hello, World!” Successfully writing a Hello World program assures the programmer that the software is successfully installed and that all necessary features are working: parsers, compilers, linkers, and so on.
I just returned home from Vancouver, British Columbia, where I attended the 2010 Joint Statistical Meetings (JSM). I heard that more than 5,300 statisticians attended this year, including about 40 or so from SAS. I stayed busy. I gave a presentation on techniques for visualizing time series, gave a two-hour
