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.
Lo how a rose e'er blooming From tender stem hath sprung As I write this blog post, a radio station is playing Chrismas music. One of my favorite Christmas songs is the old German hymn that many of us know as "Lo, How a Rose E're Blooming." I was humming
The most recent development environment for SAS programmers is SAS Studio, which is a browser-based application. The free SAS University Edition, which includes SAS/IML software, also uses SAS Studio as a development environment. SAS Studio has a special mode for programmers who use interactive procedures such as PROC IML. (Recall
Recently Sanjay Matange blogged about how to color the bars of a histogram according to a gradient color ramp. Using the fact that bar charts and histograms look similar, he showed how to use PROC SGPLOT in SAS to plot a bar chart in which each bar is colored according
A SAS customer asked: Why isn't the chi-square distribution supported in PROC UNIVARIATE? That is an excellent question. I remember asking a similar question when I first started learning SAS. In addition to the chi-square distribution, I wondered why the UNIVARIATE procedure does not support the F distribution. These are
Last week my colleague Chris Hemedinger published a blog post that described how to use the ODS LAYOUT GRIDDED statement to arrange tables and graphs in a panel. The statement was introduced in SAS 9.4m1 (December 2013). Gridded layout is supported for HTML, POWERPOINT, and the PRINTER family of destinations
When creating a statistical graphic such as a line plot or a scatter plot, it is sometimes important to preserve the aspect ratio of the data. For example, if the ranges of the X and Y variables are equal, it can be useful to display the data in a square
A matrix is a convenient way to store an array of numbers. However, often you need to extract certain elements from a matrix. The SAS/IML language supports two ways to extract elements: by using subscripts or by using indices. Use subscripts when you are extracting a rectangular portion of a
Sometimes you are writing a program that needs to find out whether a particular SAS product (like SAS/ETS, SAS/QC, or SAS/OR) is licensed. I was reminded of this fact when I wrote last week's blog post about how to create a map with PROC SGPLOT. Although the SGPLOT procedure is
Did you know that you can use the POLYGON statement in PROC SGPLOT to draw a map? The graph at the left shows the 48 contiguous states of the US, overlaid with markers that indicate the locations of major cities. The plot was created by using the POLYGON statement, which
In many procedures, the ID statement is used to identify observations by specifying an identifying variable, such as a name or a patient ID. In many regression procedures, you can specify multiple ID variables, and all variables are copied into output data sets that contain observation-wise statistics such as predicted
