topic Re: Simple Matrix Extraction in Discussions

Simple Matrix Extraction

mjaisit — Thu, 09 Jan 2014 19:19:07 GMT

Quick question about extracting a single column from a large matrix into a submatrix. Just as an example below: I want extract the second column from matrix P ( I want to pull out 2,5,8) and place it into a submatrix called A. However when I try to attempt it in this way, I am getting invalid matrix token error.

P=[1 2 3, 4 5 6, 7 8 9];

for(i=1,i<=3,i = i + 1,

A = [P[i,2]];

);

Should be really simple, but for some reason it is stumping me. Thanks for the help!

Re: Simple Matrix Extraction

mattflynn — Thu, 09 Jan 2014 19:34:07 GMT

see:

JSL Tip: Use Matrices Instead of Lists

Xan Gregg June 15, 2009

http://www.jmp.com/support/help/Matrix_Functions.shtml

http://blogs.sas.com/content/jmp/2009/06/15/jsl-tip-use-matrices-instead-of-lists/

http://www.jmp.com/support/help/Matrix_Functions.shtml

also:

http://www.jmp.com/support/help/Matrix_Functions.shtml

http://www.jmp.com/support/help/Matrices.shtml

p=[1 2 3, 4 5 6, 7 8 9];

A = J(1,3);

for(i=1,i<-=3,i++

A = P[i,2[;

);

Best regards,

-Matt

Re: Simple Matrix Extraction

Jeff_Perkinson — Thu, 09 Jan 2014 19:45:49 GMT

Matt's pointing you in the right direction.

Here's a more specific set of documentation on Subsetting Matrices.

The answer at the end of the book is that a subscript argument of zero selects all rows or columns.

P=[1 2 3, 4 5 6, 7 8 9];

A=P[0,2];

-Jeff

Re: Simple Matrix Extraction

mjaisit — Fri, 10 Jan 2014 01:06:19 GMT

Thanks guys for the quick help!