The DO Loop
Statistical programming in SAS with an emphasis on SAS/IML programs![Top posts from The DO Loop in 2018 Calibration plot for a misspecified logistic model](https://blogs.sas.com/content/iml/files/2018/05/calibrationplot2-640x336.png)
Last year, I wrote more than 100 posts for The DO Loop blog. Of these, the most popular articles were about data visualization, SAS programming tips, and statistical data analysis. Here are the most popular articles from 2018 in each category. Data Visualization Visualize repetition in song lyrics: In one
![Visualize a mixed model that has repeated measures or random coefficients](https://blogs.sas.com/content/iml/files/2018/12/VizMixed3-640x336.png)
I regularly see questions on a SAS discussion forum about how to visualize the predicted values for a mixed model that has at least one continuous variable, a categorical variable, and possibly an interaction term. SAS procedures such as GLM, GENMOD, and LOGISTIC can automatically produce plots of the predicted
![Create a probability plot in SAS](https://blogs.sas.com/content/iml/files/2018/12/ProbPlot4-640x336.png)
Many data analysts use a quantile-quantile plot (Q-Q plot) to graphically assess whether data can be modeled by a probability distribution such as the normal, lognormal, or gamma distribution. You can use the QQPLOT statement in PROC UNIVARIATE to create a Q-Q plot for about a dozen common distributions. However,
![The essential guide to bootstrapping in SAS Process flow diagram shows how to resample data to create a bootstrap distribution.](https://blogs.sas.com/content/iml/files/2018/12/bootstrapSummary-702x336.png)
This article describes best practices and techniques that every data analyst should know before bootstrapping in SAS. The bootstrap method is a powerful statistical technique, but it can be a challenge to implement it efficiently. An inefficient bootstrap program can take hours to run, whereas a well-written program can give
![Visualize Christmas songs](https://blogs.sas.com/content/iml/files/2018/12/VizXmasSong3-600x336.png)
The best way to spread Christmas cheer is singing loud for all to hear! -Buddy in Elf In the Christmas movie Elf (2003), Jovie (played by Zooey Deschanel) must "spread Christmas cheer" to help Santa. She chooses to sing "Santa Claus is coming to town," and soon all of New
![When is a histogram not a histogram? When it's a table!](https://blogs.sas.com/content/iml/files/2018/12/histtable1-702x336.png)
Recently a SAS programmer wanted to obtain a table of counts that was based on a histogram. I showed him how you can use the OUTHIST= option on the HISTOGRAM statement in PROC UNIVARIATE to obtain that information. For example, the following call to PROC UNIVARIATE creates a histogram for