How to add matrix of different orders

How can I add two matrix in which one is bigger than the other: A=[3 5 6 7;6 1 2 3] B=[2 4 5;5 7 8]

I want to make B the same order as A, adding zeros,in order to perform an addition between them, so B=[2 4 5 0;5 7 8 0] How do I perform this operation to B knowing the dimensions of A?

Answer 1

[Peta]

If this dynamically changes over time I would calculate the difference in the width of the matrices like this first:

sizediff = size(A,2)-size(B,2);

And then use the horzcat command to pad the B variable, either by writing this:

B = horzcat(B,zeros(size(B,1),sizediff))

or this:

B = [B,zeros(size(B,1),sizediff)]

or potentially even this:

B = cat(2,B,zeros(size(B,1),sizediff))