How to interchange elements of an array?

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X = [ 4 2 3 6 5 1]
x1 = [2 3 1 2]
I want to interchange entries of X based on x1, that is
Output X =[4 6 2 3 5 1];
Any help is appreciated.

Accepted Answer

Voss
Voss on 27 Mar 2022
X = [ 4 2 3 6 5 1];
x1 = [2 3 1 2];
Xnew = X;
for ii = 1:numel(x1)
Xnew([ii x1(ii)]) = Xnew([x1(ii) ii]);
end
Xnew
Xnew = 1×6
4 6 2 3 5 1
  2 Comments
Noor Fatima
Noor Fatima on 28 Mar 2022
@_Thank you, Is it possible without loop?
Voss
Voss on 28 Mar 2022
Well, you can write down an expression to do it in this particular case:
X = [ 4 2 3 6 5 1];
Xnew = X([1 4 2 3 5 6])
Xnew = 1×6
4 6 2 3 5 1
But I don't think you can do it in general without using a loop somewhere, because the result of any swap depends on the results of the previous swaps, so it's necessarily an iterative process.

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