From: "Nils Wagner" nwagner@isd.uni-stuttgart.de
A matrix operation is that of stacking the columns of a matrix one under the other to form a single column. This operation is called "vec" or "cs" (c)olumn (s)tring
Example
A is a m * n matrix
vec(A) = reshape(transpose(A),(m*n,1))
I assume you mean:
def vec(A): reshape(transpose(A), (m*n,1))
First off, the following is a bit simpler and means you don't have to carray m and n around
def vec(A): reshape(transpose(A), (-1,1))
How can I copy the result of vec(A) into the i-th column of another matrix called B ?
B = zeros([m*n, p]) B[:,i:i+1] = vec(A)
However, I don't think this is what you really want. I suspect you'd be happier with:
B[:,i] = ravel(A)
Ravel turns A into an m*n length vector [shape (m*n,)] instead of m*n by 1 array [shape (m*n,1)]. If all you want to do is insert it into B, this is going to be more useful.
-tim