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Tag: Reading and Writing Data

Rick WicklinMarch 21, 2012 0

Creating symmetric matrices: Two useful functions with strange names

Covariance, correlation, and distance matrices are a few examples of symmetric matrices that are frequently encountered in statistics. When you create a symmetric matrix, you only need to specify the lower triangular portion of the matrix. The VECH and SQRVECH functions, which were introduced in SAS/IML 9.3, are two functions

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Rick WicklinJanuary 16, 2012 0

Reading ALL variables INTO a matrix

The SAS/IML READ statement has a few convenient features for reading data from SAS data sets. One is that you can read all variables into vectors of the same names by using the _ALL_ keyword. The following DATA steps create a data set called Mixed that contains three numeric and

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Rick WicklinNovember 28, 2011 0

Reading variables with a common prefix

I got an email asking the following question: In the following program, I don't know how many variables are in the data set A. However, I do know that the variable names are X1–Xk for some value of k. How can I read them all into a SAS/IML matrix when

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