get specific elements from matrix

Hello,

From an arbitrary matrix I want to extract n elements when I have 2 arrays of lenth n, one containing the row indices and 1 containing the column indices of the desired elements.

For effeciency I would like to avoid a for loop. Is this possible?

Thanks!

[Richard]

could you provide an example?

[Erik de Boer]

Sure

Say I have a matrix A =

[3 6 2

5 1 3

4 7 8]

Row vector R = [1 2 3] and column vector C = [3 1 1]

Then I want to etract the elements [1,3],[2,1],[3,1] and arrive at

ans = [2 5 4]

Walter Robertson's aswer does exactly that. Thanks!

Answer 1

[Walter Roberson]

YourMatrix( sub2ind( size(YourMatrix), Rows, Columns ) )