Your question is not very clear. The code you show generates a matrix of integer between 0 and 3 (included), not 0 and 1, because the first input you pass to randi is 4 (and you subtract 1) from the result. If you weren't aware that the first input is the upper bound of the integers generated by randi, perhaps you should look at the documentation.
To generate a binary matrix of size MxNxP:
A = randi([0 1], M, N, P)
