Part of the problem is that you're trying to push a 749x2 matrix into an array of 749x1 size (BMactive(:,jj) only calls one column at a time).
As for creating 20 matrices, do you really need 20 matrices, or do you just want 20 sets of the information? Creating a number of matrices is generally not recommended with MATLAB, instead we generally recommend you index to another dimension. See the following as an example:
for ii=1:Nco; % Is there more content within the loop? Because this doesn't actually do anything with
% what you've posted
for jj=1:Nyrs
BMactive(:,:,jj) = [idact(:), BMact(:,jj)]; % Adjusted BMactive indexing
end
end
The simple change implemented should change BMactive to be the size of 749x2x20, where each 'sheet' is your 749x2 array that you wanted to put into a separate array. If you need to call it specifically, just index to the desired sheet.
If this does not address your problem at all, please explain more, because I clearly don't understand.
