"Subscripted assignment dimension mismatch" when using a for loop

I'm having a problem with the following iteration

for i=L:N
    e(it,1) = x(i) - flipud(y(i-L+1:i,1))' * g(:,it); %Here is the error
    g(:,it+1) = g(:,it) + mu * flipud(y(i-L+1:i,1)) * e(it,1);    
    it = it + 1;
end

When I execute the whole code I get "Subscripted assignment dimension mismatch." error in the signaled line. I have reviewed some other posts about this error, but I don't understand how can I solve it in my code. The variable 'e' is expected to be a matrix which saves a line in every iteration.

[Star Strider]

Please give the actual sizes of these in each iteration:

• flipud(y(i-L+1:i,1))'
• g(:,it)

Answer 1

[MHN]

There is a mismatch here:

flipud(y(i-L+1:i,1))' * g(:,it);

You have a L*1 matrix (flipud(y(i-L+1:i,1))) and you are transposing that so it would be 1*L. So, g(:,it) must be a L*1 matrix, otherwise you will get this error.