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When I finished writing my book, Statistical Programming with SAS/IML Software, I was elated. However, one small task still remained. I had to write the index. How Long Should an Index Be? My editor told me that SAS Press would send the manuscript to a professional editor who would index
Paula Joshi wrote last month about how what we learn from the commercial world can be applied in government. She also promised to post a few examples. I’ll get that ball rolling. This week SAS announced the availability of SAS Enterprise Case Management. While the announcement focuses more on the
Recently, I needed to detect whether a matrix consists entirely of missing values. I wrote the following module: proc iml; /** Module to detect whether all elements of a matrix are missing values. Works for both numeric and character matrices. Version 1 (not optimal) **/ start isMissing(x); if type(x)='C' then
NOTE: SAS stopped shipping the SAS/IML Studio interface in 2018. The references in this article to IMLPlus and SAS/IML Studio are no longer relevant. There are three kinds of programming errors: parse-time errors, run-time errors, and logical errors. It doesn't matter what language you are using (SAS/IML, MATLAB, R, C/C++,
I helped to write a quiz for the Computer Science Education Week promotions that were featured on our company intranet. Do you fancy yourself as a Comp-Sci aficionado? Let's see how you do with these. 1. Which achievement is Charles Babbage most famous for? A. Establishing software retail shops in
Imagine you are attending the BCS National Championship game next month. You have invested top dollar in your seats and you have been anticipating the game for weeks. You settle in to your seat with your hot dog, soft pretzel, and your favorite beverage a few minutes before kick-off because
Both covariance matrices and correlation matrices are used frequently in multivariate statistics. You can easily compute covariance and correlation matrices from data by using SAS software. However, sometimes you are given a covariance matrix, but your numerical technique requires a correlation matrix. Other times you are given a correlation matrix,
I connect to more SAS server environments than your average SAS user. In a given week, I probably run SAS Enterprise Guide connecting to at least five different Windows-based servers, a few Unix-based servers, and maybe even a z/OS machine as well. With that many SAS environments, I'm bound to
Sample covariance matrices and correlation matrices are used frequently in multivariate statistics. This post shows how to compute these matrices in SAS and use them in a SAS/IML program. There are two ways to compute these matrices: Compute the covariance and correlation with PROC CORR and read the results into
I enjoy reading about the Le Monde puzzles (and other topics!) at Christian Robert's blog. Recently he asked how to convert a number with s digits into a numerical vector where each element of the vector contains the corresponding digit (by place value). For example, if the number is 4321,
Computer science is more than the pursuit of "let's see what we can make this computer do." If that's your only goal, then you might make a fine computer geek, but a lousy computer scientist. In her blog post for Computer Science Education Week, Caroline McCullen reminds us that computer
The SAS/IML language enables you to perform matrix-vector computations. However, it also provides a convenient "shorthand notation" that enables you to perform elementwise operation on rows or columns in a natural way. You might know that the SAS/IML language supports subscript reduction operators to compute basic rowwise or columnwise quantities.
My last post was a criticism of a statistical graph that appeared in Bloomberg Businessweek. Criticism is easy. Analysis is harder. In this post I re-analyze the data to present two graphics that I think should have replaced the one graphic in Businessweek. You can download the SAS program that
Have you used multivariate procedures in SAS and wanted to save out scores? Some procedures, such as FACTOR, CANDISC, CANCORR, PRINCOMP, and others have an OUT= option to save scores to the input data set. However, to score a new data set, or to perform scoring with multivariate procedures that
It seems like each week brings news announcing yet another software vendor acquisition by one of the giant software conglomerates. This approach of purchasing a specific capability to fit into the ever growing portfolio of technology does not show signs of stopping in the near future. Matter of fact, several