Plotting multiple time series in SAS/IML (Wide to Long, Part 2)

I recently wrote about how to overlay multiple curves on a single graph by reshaping wide data (with many variables) into long data (with a grouping variable). The implementation used PROC TRANSPOSE, which is a procedure in Base SAS. When you program in the SAS/IML language, you might encounter data […]
Post a Comment

Plotting multiple series: Transforming data from wide to long

Data. To a statistician, data are the observed values. To a SAS programmer, analyzing data requires knowledge of the values and how the data are arranged in a data set. Sometimes the data are in a "wide form" in which there are many variables. However, to perform a certain analysis […]
Post a Comment

Popular posts from The DO Loop in 2014

I published 118 blog posts in 2014. This article presents my most popular posts from 2014 and late 2013. 2014 will always be a special year for me because it was the year that the SAS University Edition was launched. The University Edition means that SAS/IML is available to all […]
Post a Comment

Resampling and permutation tests in SAS

My colleagues at the SAS & R blog recently posted an example of how to program a permutation test in SAS and R. Their SAS implementation used Base SAS and was "relatively cumbersome" (their words) when compared with the R code. In today's post I implement the permutation test in […]
Post a Comment

The distribution of blood types by country

My colleague Robert Allison has a knack for finding fascinating data. Last week he did it again by locating data about how blood types and Rh factors vary among countries. He produced a series of eight world maps, each showing the prevalence of a blood type (A+, A-, B+, B-, […]
Post a Comment

Binning data by quantiles? Beware of rounded data

In my article about how to create a quantile plot, I chose not to discuss a theoretical issue that occasionally occurs. The issue is that for discrete data (which includes rounded values), it might be impossible to use quantile values to split the data into k groups where each group […]
Post a Comment

Does this kurtosis make my tail look fat?

What is kurtosis? What does negative or positive kurtosis mean, and why should you care? How do you compute kurtosis in SAS software? It is not clear from the definition of kurtosis what (if anything) kurtosis tells us about the shape of a distribution, or why kurtosis is relevant to […]
Post a Comment

The frequency of double-letters in Cryptoquotes

It usually takes more than three weeks to prepare a good impromptu speech.        --Mark Twain In the popular Cryptoquote puzzle, you are presented with an enciphered version of a quote by a famous person. One of the appeals of the puzzle for me is reading the deciphered quote, such […]
Post a Comment

Which double letters appear most frequently in English text?

Double, double toil and trouble; Fire burn, and caldron bubble.     Macbeth, Act IV, Scene I For the cyptanalyst or recreational puzzle solver, "double double" does not lead to toil or trouble. Just the opposite: The occurrence of a double-letter bigram in an enciphered word puzzle is quite fortunate. Certain double […]
Post a Comment

Create discrete heat maps in SAS/IML

In a previous article I introduced the HEATMAPCONT subroutine in SAS/IML 13.1, which makes it easy to visualize matrices by using heat maps with continuous color ramps. This article introduces a companion subroutine. The HEATMAPDISC subroutine, which also requires SAS/IML 13.1, is designed to visualize matrices that have a small […]
Post a Comment