zero padding a matrix

Question

I have a 16X16 matrix. I have to add it to a 256X256 matrix. Can anyone help me how to make this 16X16 matrix into 256X256 filling the remaining with zeros?

Answer 1

Matlab automatically pads with zeros if you assign something to an element outside of the original size.

>> A = rand(16, 16);
>> A(256, 256) = 0;
>> size(A)
ans =
   256   256

Answer 2

padded = zeros(256,256);
data = rand(16,16);
padded(1:16,1:16) = data;