topic Converting a Vector into a Matrix in SAS/IML Software and Matrix Computations

Converting a Vector into a Matrix

MarkGIP — Wed, 16 Nov 2011 21:24:40 GMT

Hi everyone!

Maybe you could help me with my latest obstacle I've encountered with IML. Do you happen to know how to convert a vector into a matrix?

Here is a little example to give you a better idea:

Given:

Vector n (1000x1)

Goal:

Convert vector n into a 50x20 matrix m. The first column of matrix m should be equal to the first 50 elements of vector n. The second column should be equal to the next 50 elements and so on.

It would be great if you had a solution for this problem... Thanks a million!!!

Converting a Vector into a Matrix

Rick_SAS — Wed, 16 Nov 2011 21:36:48 GMT

Use the SHAPE function.

A blog article on reshaping matrices is here: http://blogs.sas.com/content/iml/2010/10/11/how-can-you-reshape-a-matrix/

The SHAPE function arranges the elements rowwise, so the first ROW of m contains the first consecutive elements:

v = 1:1000;

w = shape(v, 20, 50); /* w is 20 x 50 */

To get the data in column-wise order, transpose w:

m = T(w); /* m is 50 x 20 */

Rick

Statistical programming blog: http://blogs.sas.com/content/iml

Converting a Vector into a Matrix

MarkGIP — Wed, 16 Nov 2011 22:24:06 GMT

Wow... that went fast! Thank you so much Rick!!!