The DO Loop
Statistical programming in SAS with an emphasis on SAS/IML programs![How to use transparency to overcome overplotting](https://blogs.sas.com/content/iml/files/2011/08/transparent1.png)
Do you have many points in your scatter plots that overlap each other? If so, your graph exhibits overplotting. Overplotting occurs when many points have similar coordinates. For example, the following scatter plot (which is produced by using the ODS statistical graphics procedure, SGPLOT) displays 12,000 points, many of which
![The macro loop that vanished: How to simplify your SAS/IML programs](https://blogs.sas.com/content/iml/files/2017/01/AdvancedAnalytics-1.png)
I don't use the SAS macro language very often. Because the SAS/IML language has statements for looping and evaluating expressions, I rarely write a macro function as part of a SAS/IML programs. Oh, sure, I use the %LET statement to define global constants, but I seldom use the %DO and
![Simulation and sampling in Las Vegas](https://blogs.sas.com/content/iml/files/2011/08/tipsheet.png)
If you haven't signed up for SAS Global Forum 2011 in Las Vegas, you'd better get moving: February 28 is the last day for early registration and the discounted hotel prices. You should also sign up for the pre-conference statistical tutorials, which are filling up fast! I was tempted to
![Bias and covariance explained to an 11-year-old](https://blogs.sas.com/content/iml/files/2011/08/target.png)
I was inspired by Chris Hemedinger's blog posts about his daughter's science fair project. Explaining statistics to a pre-teenager can be a humbling experience. My 11-year-old son likes science. He recently set about trying to measure which of three projectile launchers is the most accurate. I think he wanted to
![SAS/IML operations compared with PROC SQL: Part 1](https://blogs.sas.com/content/iml/files/2011/08/t_sql_mono.png)
I don't know much about the SQL procedure, but I know that it is powerful. According to the SAS documentation for the SQL procedure, "PROC SQL can perform some of the operations that are provided by the DATA step and the PRINT, SORT, and SUMMARY procedures." Recently, a fellow blogger,
![How to build a vector from expressions](https://blogs.sas.com/content/iml/files/2017/01/AdvancedAnalytics-2.png)
If you are a statistical programmer, sooner or later you have to compute a confidence interval. In the SAS/IML language, some beginning programmers struggle with forming a confidence interval. I don't mean that they struggle with the statistics (they know how to compute the relevant quantities), I mean that they