The Kronecker product (also called the direct product) is a binary operation that combines two matrices to form a new matrix. The Kronecker product appears in textbooks about the design of experiments and multivariate statistics. The Kronecker product seems intimidating at first, but often one of the matrices in the
I previously wrote about the advantages of adding horizontal and vertical reference lines to a graph. You can also add a diagonal reference line to a graph. The SGPLOT procedure in SAS supports two primary ways to add a diagonal reference line: The LINEPARM statement enables you to specify a
Data tell a story. A purpose of data visualization is to convey that story to the reader in a clear and impactful way. Sometimes you can let the data "speak for themselves" in an unadorned graphic, but sometimes it is helpful to add reference lines to a graph to emphasize
