Averaging setions of a matix

Good day,

Could someone please help me on how to average row one to nth row of a matrix and build another matrix with the out put.

For instance, for a matrix 'A' of 20 x 5, I would like to build another matrix of which its first row is an average of the first two rows of A, the 2nd row is the average of first three rows of A and the third row is the average of the 1st four rows of A, until the last row of matrix A.

I tried the loop shown below but I got an error that dimension of the right and left side are not the same.

for f=1:1:n

k=mean(B(1:n,:))

f

Avg(:,f)=k

end

Thanks in advance

Answer 1

[dpb]

mnA=cell2mat(arrayfun(@(n)mean(A(1:n,:)),[2:size(A,1)].','uni',0));

[AUWAL ABUBAKAR]

This is awsome!

It works fine.

Thanks for your help

Answer 2

[Andrei Bobrov]

out = cumsum(A)./(1:size(A,1))';
mnA = out(2:end,:);