Ugh! Your favorite regression procedure just printed a warning to the SAS log. Something is wrong, and your attempt to fit a model to the data has not succeeded. A typical message is "WARNING: The validity of the model fit is questionable," perhaps followed by some additional diagnostic messages about
One of my presentations at SAS Global Forum 2015 was titled "Ten Tips for Simulating Data with SAS". The paper was published in the conference proceedings several months ago, but I recently recorded a short video that gives an overview of the 10 tips: If your browser does not support
I wanna be an airborne ranger, Live the life of guts and danger.* If you are an 80's movie buff, you might remember the scene in The Breakfast Club where Bender, the juvenile delinquent played by Judd Nelson, distracts the principal by running through the school singing this song. Recently,
Typically a correlation analysis reports the correlations between all pairs of variables, including the variables with themselves. The resulting correlation matrix is square, symmetric, and has 1s on the main diagonal. But suppose you are interested in only specific combinations of variables. Perhaps you want the pairwise correlations between one
When SAS 9.4m3 was released last month (including SAS/STAT and SAS/IML 14.1), I was happy to see that a HEATMAP statement had been added to the SGPLOT procedure. Although heat maps in the SAS/IML language have been available for several releases, you previously had to use the Graph Template Language
Last month I wrote about how to simulate a drunkard's walk in SAS for a drunkard who can move only left or right in one direction. A reader asked whether the problem could be generalized to two dimensions. Yes! This article shows how to simulate a 2-D drunkard's walk, also
When using SAS to format a number as a percentage, there is a little trick that you need to remember: the width of the formatted value must include room for the decimal point, the percent sign, and the possibility of two parentheses that indicate negative values. The field width must
Last week's post about odds ratio plots in SAS made me think about a similar plot that visualizes the parameter estimates for a regression analysis. The so-called regression coefficient plot is a scatter plot of the estimates for each effect in the model, with lines that indicate the width of
Imagine the following scenario. You have many data sets from various sources, such as individual stores or hospitals. You use the SAS DATA step to concatenate the many data sets into a single large data set. You give the big data set to a colleague who will analyze it. Later
Last week, SAS released the 14.1 version of its analytics products, which are shipped as part of the third maintenance release of 9.4. If you run SAS/IML programs from a 64-bit Windows PC, you might be interested to know that you can now create matrices with about 231 ≈ 2
