MATLAB: Matrix addition of a first column in a loop

Question

i have a cell A with 'n' cells inside. inside each cell i have a matrix. i want to do matrix addition of all the first column of these matrices inside a for loop. how to do it?

for i=1:n
  % matrix addition code
end

Answer 1

With a loop:

colsum = yourcellarray{1}(:, 1);
for cidx = 2:numel(yourcellarray)
  colsum = colsum + yourcellarray{cidx}(:, 1);
end

With cellfun:

colsum = sum(cell2mat(@(m) m(:, 1), yourcellarray, 'UniformOutput', false)), 2);

Either way, the matrices in each cell must have the same height.

Note that if all the matrices in the same array are the same size, then storing them as an N-d array (where N = ndim(yourmatrices)+1) would make your life much easier:

allmatrices = cat(ndim(yourcellarray{1})+1, yourcellarray{:});
colsum = sum(allmatrices(:, 1), ndim(allmatrices));