How to store multiple column vector generated from a for loop?

I have a function called func which returns A, B, C and D. This A, B, C, D each are 12 elements column vector. I am using this code

for delta = 0: 1: 40
    [A,B,C,D] = func(delta);
    end

Now after completing the for loop i will get 41 sets of A, B, C and D. How can i store them together?

I tried this

store = 0
   for delta = 0: 1: 40
     [A(store),B(store),C(store),D(store)] = func(delta);
   end

But obviously there is an error like A(I) = X: X must have the same size as I. cause A is storing a 12 element column vector.

Answer 1

[Stephen23]

N = 41;
A = nan(12,N);
B = nan(12,N);
C = nan(12,N);
D = nan(12,N);
for k = 1:N
    [A(:,k),B(:,k),C(:,k),D(:,k)] = fun(k-1);
end

This will give four matrices with all of the output data.

[Mr. 206]

I am having problem with delta = 0: 0.077: 0.385. How to use this values?

[Stephen23]

delta = 0:0.077:0.385;
N = numel(delta);
A = nan(12,N);
B = nan(12,N);
C = nan(12,N);
D = nan(12,N);
for k = 1:N
    [A(:,k),B(:,k),C(:,k),D(:,k)] = fun(delta(k));
end

[Mr. 206]

I did this, but the problem is all the values are same as A.

delta = 0:0.077:0.385;
  N = numel(delta);
A = nan(12,N);
B = nan(12,N);
C = nan(12,N);
D = nan(12,N);
  for kk = 1:N
  A(:,kk) = func(delta(kk));
  B(:,kk) = func(delta(kk));
  C(:,kk) = func(delta(kk));
  D(:,kk) = func(delta(kk));
  end
  A
  B
  C
  D

[Stephen23]

"I did this, but the problem is all the values are same as A."

No, you actually did something else entirely: you called your function four times.

Your code:

for kk = 1:N
    A(:,kk) = func(delta(kk));
    B(:,kk) = func(delta(kk));
    C(:,kk) = func(delta(kk));
    D(:,kk) = func(delta(kk));
end

My code:

[A(:,k),B(:,k),C(:,k),D(:,k)] = fun(delta(k));

Do you see that my code has four output arguments from fun, just like your original function? Whereas you, for no obvious reason, decided to call your function four times, each time with just one output argument. So no surprises that your code will just get the same output four times.

[Mr. 206]

Great! A slight mistake in my `func` file.

Thanks

Can you help a bit more?

After completing the procedure for A there is 12 by N matrix. How can i find out the smallest value in each row of that matrix and if the smallest value is found for which delta is responsible for the the smallest value?

So that i can find a matrix A which is a 12 by 1 matrix comprised of all the smallest value in each row. And another 12 by 1 matrix which is comprised of the delta value responsible for those smallest values.

I hope my Question is clear. Again thanks for the previous help.

[Stephen23]

"How can i find out the smallest value in each row of that matrix and if the smallest value is found for which delta is responsible for the the smallest value?"

[val,idx] = min(A,[],2)
delta(idx)

Answer 2

[KSSV]

clc; clear all ;
iwant = zeros(4,12,40) ;
for delta = 1: 40
    [A,B,C,D] = func(delta);
    iwant(:,:,delta) = [A B C D] ;
end

Note that MATLAB index starts from 1 not zero.

[Mr. 206]

Actually my real value for delta is 0: 0.077: 0.385. How to use this values?

[KSSV]

delta = 0: 0.077: 0.385 ;
N = length(delta) ;
iwant = zeros(4,12,N) ;
for i = 1:N
    [A,B,C,D] = func(delta(i));
    iwant(:,:,i) = [A B C D] ;
end

[Mr. 206]

Here you store all A,B,C,D together. I wanted all the A together in one column matrix, then in another matrix all the B, in aother all the C....... together.

[KSSV]

delta = 0: 0.077: 0.385 ;
N = length(delta) ;
A = zeros(12,N) ; 
B = A ;
C = A ;
D = A ;
for i = 1:N
    [a,b,c,d] = func(delta(i));
     A(:,i) = a ;  B(:,i) = b ; 
     C(:,i) = c ;  D(:,i) = d ;       
end

[KSSV]

YOu should check your function output...

[Mr. 206]

Thanks! It was my Mistake. Thanks for your help