About this blog
Rick Wicklin, PhD, is a senior 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 book Statistical Programming with SAS/IML Software.
Follow @RickWicklin on Twitter.
Rick Wicklin
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Research Statistician Developer
Rick Wicklin, PhD, is a senior 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 book Statistical Programming with SAS/IML Software. Follow @RickWicklin on Twitter.
Recent Posts
The curious case of random eigenvalues
I've been a fan of statistical simulation and other kinds of computer experimentation for many years. For me, simulation is a good way to understand ... Read More
How to read data set variables into SAS/IML vectors
One of the first skills that a beginning SAS/IML programmer learns is how to read data from a SAS data set into SAS/IML vectors. (Alternatively, ... Read More
The power method: compute only the largest eigenvalue of a matrix
When I was at SAS Global Forum last week, a SAS user asked my advice regarding a SAS/IML program that he wrote. One step of ... Read More
Checking your answers: Are computed values close to the true values?
In statistical programming, I often test a program by running it on a problem for which I know the correct answer. I often use a ... Read More
Expand data by using frequencies
A reader asked: I want to create a vector as follows. Suppose there are two given vectors x=[A B C] and f=[1 2 3]. Here ... Read More
The DIF function: Compute lagged differences and finite differences
To a statistician, the DIF function (which was introduced in SAS/IML 9.22) is useful for time series analysis. To a numerical analyst and a statistical ... Read More
The LAG function: Useful for more than time series analysis
To a statistician, the LAG function (which was introduced in SAS/IML 9.22) is useful for time series analysis. To a numerical analyst and a statistical ... Read More
Popular! Articles that strike a chord with SAS users
Next week I will be in Orlando for SAS Global Forum 2012. If you will be there too, I hope you will try to find ... Read More
Extending SAS: How to define new functions in PROC FCMP and SAS/IML software
SAS software provides many run-time functions that you can call from your SAS/IML or DATA step programs. The SAS/IML language has several hundred built-in statistical ... Read More
For each observation, find the variable that contains the minumum value