How to store multiple column vector generated from a for loop?
显示 更早的评论
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.
采纳的回答
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.
6 个评论
Mr. 206
2018-11-12
Stephen23
2018-11-12
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
Stephen23
2018-11-12
"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.
"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)
更多回答（1 个）
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.
6 个评论
Mr. 206
2018-11-12
KSSV
2018-11-12
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
2018-11-12
KSSV
2018-11-12
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
2018-11-12
YOu should check your function output...
Mr. 206
2018-11-12
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