The TV show Cheers was set in a bar "where everybody knows your name." Global knowledge of a name is appealing for a neighborhood pub, but not for a programming language. Most programming languages enable you to define functions that have local variables: variables whose names are known only inside
In my constant effort to keep pace with Chris Hemedinger, I am pleased to announce the availability of my new book, Simulating Data with SAS. Chris started a tradition for SAS Press authors to post a photo of themselves with their new book. Thanks to everyone who helped with the
I've previously described how to overlay two or more density curves on a single plot. I've also written about how to use PROC SGPLOT to overlay custom curves on a graph. This article describes how to overlay a density curve on a histogram. For common distributions, you can overlay a
I recently showed someone a trick to create a graph, and he was extremely pleased to learn it. The trick is well known to many SAS users, but I hope that this article will introduce it to even more SAS users. At issue is how to use the SGPLOT procedure
I often see variations of the following question posted on statistical discussion forums: I want to bin the X variable into a small number of values. For each bin, I want to draw the quartiles of the Y variable for that bin. Then I want to connect the corresponding quartile
In this International Year of Statistics, I'd like to describe the major role of statistics in public health advances. In our modern society, it is sometimes difficult to recall the huge advances in health and medicine in the 20th century. To name a few: penicillin was discovered in 1928, risk
A SAS customer asks: How do I use SAS to generate multiple samples of size N from a multivariate normal distribution? Suppose that you want to simulate k samples (each with N observations) from a multivariate normal distribution with a given mean vector and covariance matrix. Because all of the
ODS statements are global SAS statements. As such, you can put them anywhere in your SAS program. For maximum readability, many SAS programmers agree that most ODS statements should appear outside procedures in "open" SAS code. For example, most programmers agree that the following statements should appear outside of procedures:
I was recently asked how to compute the difference between two density estimates in SAS. The person who asked the question sent me a link to a paper from The Review of Economics and Statistics that contains several examples of this technique (for example, see Figure 3 on p. 16
Did you know that your ODS style might result in changing the color ramp for contour plots and heat maps? For example, the default style in SAS 9.3 is HTMLBlue. Let's create a contour plot in the HTML destination by running an example adapted from the documentation for the RSREG
