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Simple Matrix Extraction

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!

1 ACCEPTED SOLUTION

Accepted Solutions  Jeff_Perkinson Community Manager

Re: Simple Matrix Extraction

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

-Jeff
3 REPLIES 3
Highlighted

see:

JSL Tip: Use Matrices Instead of Lists

Xan Gregg June 15, 2009
p=[1 2 3, 4 5 6, 7 8 9];
A = J(1,3);
for(i=1,i<-=3,i++
A = P[i,2[;
);
A
Best regards,
-Matt  Jeff_Perkinson Community Manager

Re: Simple Matrix Extraction

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

-Jeff

Re: Simple Matrix Extraction

Thanks guys for the quick help!