compute the mean of matrices with different dimensions

I have three matrices of dimensions: matrixA: [2730 512], matrixB: [2730 512], and matrixC: [2730 256]. How do I reshape matrixC to [2730 512] by filling empty cells with zeros and compute the average of the three matrices so that the resultant matrix will be of dimension [2730 512]?

Answer 1

[Stephen23]

Z = nan(2370,512,3);
Z(:,1:512,1) = A;
Z(:,1:512,2) = B;
Z(:,1:256,3) = C;
mean(Z,3)

Answer 2

[madhan ravi]

Simple example:

A=rand(3,3);
B=rand(3,3);
C=rand(3,2);
C=[C zeros(size(A,2),1)]