How to stack k copies of a matrix

I would like to write a function which takes an integer k > 0 as input and a m by n matrix A as input and produces a m by n by k matrix such that each m by n slice is equal to A; this operation is sometimes colloquially referred to as "stacking" copies of A. It is easy to do this using for loops; we first initialize a m by n by k matrix of zeros and then iterate over the last dimension, setting each slice to be equal to A. Is there an easier way? It seems like Matlab should have built-in functions for this.

Answer 1

[David Hill]

a=reshape(repmat(A(:),k,1),[size(A),k]);

Answer 2

[James Tursa]

B = repmat(A,1,1,k);

[Walter Roberson]

Historically repmat was written in MATLAB and you could gain a bit of performance by using

B = A(1,1,ones(1,k));

However, for the last several releases repmat() has been built in, and is typically (but not always) faster.

[James Tursa]

I think you meant B = A(:,:,ones(1,k))

[Walter Roberson]

Ah, yes, you are right ;-)