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 common task in statistics is to approximate a large data matrix by using a low-rank approximation. Low-rank approximations are used for reducing the dimension of a problem (for example, in principal component analysis), for image analysis via the singular value decomposition (SVD), and for decomposing large matrices that are
Welcome to Pi Day 2026! Every year on March 14th (written 3/14 in the US), people in the mathematical sciences celebrate "all things pi-related" because 3.14 is the three-decimal approximation to π ≈ 3.14159265358979.... The purpose of this day is to have fun and celebrate the importance and ubiquity of
SAS procedures automatically generate many graphs when you turn on ODS graphics. For example, I have written about how to interpret the graphs that are produced automatically when you use PROC PRINCOMP to perform a principal component analysis (PCA). The built-in graphs are well-designed and informative, but this article discusses
