The DO Loop
Statistical programming in SAS with an emphasis on SAS/IML programsA SAS programmer was trying to implement an algorithm in PROC IML in SAS based on some R code he had seen on the internet. The R code used the rank() and order() functions. This led the programmer to ask, "What is the different between the rank and the order?
A SAS statistical programmer recently asked a theoretical question about statistics. "I've read that 'p-values are uniformly distributed under the null hypothesis,'" he began, "but what does that mean in practice? Is it important?" I think data simulation is a great way to discuss the conditions for which p-values are
At a recent conference in Las Vegas, a presenter simulated the sum of two dice and used it to simulate the game of craps. I write a lot of simulations, so I'd like to discuss two related topics: How to simulate the sum of two dice in SAS. This is
Years ago, I wrote an article that showed how to visualize patterns of missing data. During a recent data visualization talk, I discussed the program, which used a small number of SAS IML statements. An audience member asked whether it is possible to construct the same visualization by using only
A SAS programmer wanted to estimate a proportion and a confidence interval (CI), but didn't know which SAS procedure to call. He knows a formula for the CI from an elementary statistics textbook. If x is the observed count of events in a random sample of size n, then the
In a recent article, I graphed the PDF of a few Beta distributions that had a variety of skewness and kurtosis values. I thought that I had chosen the parameter values to represent a wide variety of Beta shapes. However, I was surprised to see that the distributions were all