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Rick WicklinJanuary 23, 2023 1

Use the PUTLOG statement to write errors, warning, and notes to the SAS log

Many experienced SAS programmers use the PUT statement to write messages to the log from a DATA step. But did you know that SAS supports the PUTLOG function, which is another way to write a message to the log? I use the PUTLOG statement in the DATA step for the

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Analytics | Data Visualization | Learn SAS

Rick WicklinJanuary 18, 2023 0

Visualize how parameters in a binary logistic regression model affect the probability of the event

A previous article shows that you can use the Intercept parameter to control the ratio of events to nonevents in a simulation of data from a logistic regression model. If you decrease the intercept parameter, the probability of the event decreases; if you increase the intercept parameter, the probability of

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Analytics | Learn SAS | Programming Tips

Rick WicklinJanuary 11, 2023 2

12 blog posts from 2022 that deserve a second look

In a previous article, I presented some of the most popular blog posts from 2022. In general, popular articles deal with elementary topics that have broad appeal. However, I also write articles about advanced topics. The following articles didn't make the Top 10 list, but they deserve a second look.

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Analytics | Learn SAS | Programming Tips

Rick WicklinJanuary 4, 2023 0

Top 10 posts from The DO Loop in 2022

Last year, I wrote almost 90 articles for The DO Loop blog. My most popular articles were about SAS programming, data visualization, statistics and data analysis, and matrix computations. If you missed these articles when I published them—or if you want to read them again!— here is the "Reader's Choice

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Learn SAS | Programming Tips

Rick WicklinDecember 19, 2022 2

Working with combinations in SAS

A colleague posted a Christmas-themed code snippet that shows how to use the DATA step in SAS to output all the possible ways that Santa can hitch up a team of reindeer to pull his sled. The assumption is that Rudolph must lead the team, and the remaining reindeer are

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Analytics | Learn SAS | Programming Tips

Rick WicklinDecember 14, 2022 0

Construct heterogeneous structured covariance matrices in SAS

A previous article describes how to use SAS IML software to construct common covariance structures that are encountered in mixed models. Each covariance matrix has several parameters, and you want to construct a matrix for any choice of the parameters. After you have constructed the covariance matrix, you can use

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Learn SAS | Programming Tips

Rick WicklinDecember 12, 2022 0

Properties of the Hadamard product

I always emphasize efficiency in statistical programming. I have previously written about why you should never multiply with a large diagonal matrix in the SAS IML language. The reason is that it is more efficient to use elementwise multiplication than matrix multiplication. Specifically, if d is a column vector, then

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Data Visualization | Learn SAS | Programming Tips

Rick WicklinDecember 7, 2022 0

Art in SAS: Christmas wrapping paper

For Christmas 2021, I wrote an article about palettes of Christmas colors, chiefly shades of red, green, silver, and gold. One of my readers joked that she would like to use my custom palette to design her own Christmas wrapping paper! I remembered her jest when I saw some artwork

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Learn SAS | Programming Tips

Rick WicklinNovember 30, 2022 0

Ladders: A probabilistic card trick

A probabilistic card trick is a trick that succeeds with high probability and does not require any skill from the person performing the trick. I have seen a certain trick mentioned several times on social media. I call it "ladders" or the "ladders game" because it reminds me of the

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Learn SAS | Programming Tips

Rick WicklinNovember 28, 2022 0

Simulate poker hands in SAS

A SAS programmer was trying to simulate poker hands. He was having difficulty because the sampling scheme for simulating card games requires that you sample without replacement for each hand. In statistics, this is called "simple random sampling." If done properly, it is straightforward to simulate poker hands in SAS.

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