Thread: Extract part of a matrix

Hi.

Does anyone know a way to extract just part of a matrix, say one or two rows?

One example of what I'm looking for would be:
Enter a 2x3 matrix which represents a system of 2 eq. and 2 vars. Run rref([A]) on it.

Now, I want to use the last column of the answer, and I want to multiply it by the first two columns of [A] (yes, I know I'll get the third column of [A] - this is just an example). Is there an easy way to extract column 3? Is there a way to extract the 2x2 matrix in the top right of [A]?

Thanks.

Hi,
To continue your example the data that you require may be extracted as follows:

subMat(A,1,2,3,3)

This may be saved in a variable or used directly.

Originally Posted by RHandford

Hi,
To continue your example the data that you require may be extracted as follows:

subMat(A,1,2,3,3)

This may be saved in a variable or used directly.

Thanks, RH.

To be a little clearer, I am using a TI-84+ silver. I don't see a subMat( command in the Catalog.
Sorry I wasn't more specific (no wonder so few people answered an easy question).