如何从循环保存输出数组？

Question

I have a loop which outputs variable A as an mx1 matrix (where: m>1) for each iteration. At the end of the entire loop, A will end up as an mxn matrix . Although the output is returned as an mxn matrix, it however keeps overwriting the results. I have tried so many stuffs (including the ones that have worked for my previous codes) but none seem to work. Nevertheless, i feel the code below should work but i'm not sure where the error is coming from.

x_A = NaN(28, 3); % 28=length of A and 3=length of kk
Z = [1,2,4,7];

for kk = 1: numel(Z)
   [A,B,C] = fsave_output(Z, kk)
   x_A     = [x_A(:,kk) A(:,kk)];

   % repeat the line above for B and C

end

When i run this, i get the error message: "Attempted to access x_A(:,3); index out of bounds because size(x_norm)=[28,2]." . However, the outputs in x_A(:,1) and X_A(:,2) are correct, only that x_A(:,3) doesn't show.

Any ideas/suggestions/help on what i should do here? Many thanks in advance!.

Answer 1

If you know the size of matrices to store before the loop, try

Z = [1,2,4,7];
store_A = zeros(numel(Z), m); %m is known length
store_B = zeros(numel(Z), m); %if not known, unroll first iteration of loop
store_С = zeros(numel(Z), m); %or store it in a cell and concatenate after the loop

for kk = 1: numel(Z)
   [store_A(kk,:),store_B(kk,:),store_C(kk,:)] = fsave_output(Z, kk)
end