The DO Loop

Statistical programming in SAS with an emphasis on SAS/IML programs
Programming Tips
Rick Wicklin 0
What is bilinear interpolation?

I've previously written about linear interpolation in one dimension. Bilinear interpolation is a method for two-dimensional interpolation on a rectangle. If the value of a function is known at the four corners of a rectangle, an interpolation scheme gives you a way to estimate the function at any point in

Analytics | Programming Tips
Rick Wicklin 0
Linear interpolation in SAS

SAS programmers sometimes ask about ways to perform one-dimensional linear interpolation in SAS. This article shows three ways to perform linear interpolation in SAS: PROC IML (in SAS/IML software), PROC EXPAND (in SAS/ETS software), and PROC TRANSREG (in SAS/STAT software). Of these, PROC IML Is the simplest to use and

Analytics
Rick Wicklin 1
How many imputations are enough?

Recently I read an excellent blog post by Paul von Hippel entitled "How many imputations do you need?". It is based on a paper (von Hippel, 2018), which provides more details. Suppose you are faced with data that has many missing values. One way to address the missing values is

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