multiply a 1 by 500 matrix to a 688 by 550 matrix and want to get the result for iteration instead of final value from 1 by 500 matrix!

for i = 1:5

r(:,:) = (ait(:,i)*podu);

end

ait is 1 by 500 matrix and podu is 688 by 550 matrix. Using this code gives me the result for the product of 5th value of ait times the podu matrix. I want to sum all the values for all the iteration and create a 688 by 550 matrix for r!

Thank you

[Steven Lord]

@Kai5er flagged this as Unclear stating "I think the question is unclear and i want to remove it and will upload with better explanation"

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Answer 1

[Voss]

It's not clear to me whether "all the iterations" means to iterate over the first 5 elements of ait or to iterate over all elements of ait, so the below has it both ways:

Method 1, similar to your loop:

% initialize r to be a matrix of zeros, the same size as podu
r = zeros(size(podu));
for i = 1:5                 % first 5 only, or
% for i = 1:numel(ait)      % all
    r = r + ait(i)*podu;
end

Method 2:

% sum the ait first, then multiply the sum by podu:
r = sum(ait(1:5))*podu;     % first 5 only, or
% r = sum(ait)*podu;        % all