Replacing several values in multidimensional array simultaneously

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I have a multidimensional array, e.g.
A(:,:,1) = [1 2 3 ; 4 5 6];
A(:,:,2) = [7 8 9 ; 10 11 12];
I want to replace several of the values in this array with the same value simultaneously. Specifically I want to do this column-wise, the result should be e.g.
A(:,2,1) = [-1 ; -2];
A(:,3,2) = [-1 ; -2];
yielding
A(:,:,1) = [1 -1 3 ; 4 5 -1];
A(:,:,2) = [7 -2 9 ; 10 11 -2];
I attempted this by
B = [2 3]; C = [1 2];
A(:,B,C) = [-1 ; -2];
but it does not give the wanted result.
Any idea on how to do this without performing a for-loop?

Risposta accettata

Bruno Luong
Bruno Luong il 14 Set 2020
Modificato: Bruno Luong il 14 Set 2020
A(:,:,1) = [1 2 3 ; 4 5 6];
A(:,:,2) = [7 8 9 ; 10 11 12];
s = size(A);
A(:, sub2ind(s(2:3),[2 3],[1 2])) = 0 % = [0 0; 0 0]
  2 Commenti
David Hoffmeyer
David Hoffmeyer il 14 Set 2020
Modificato: David Hoffmeyer il 14 Set 2020
Thanks for your input. However, I have not been precise enough in my question. I need to replace a number of columns in the array with a column containing non-identical values (see the edited question), and not just 0. In that case your proposal does not work. Can you alter it correspondingly?
Bruno Luong
Bruno Luong il 14 Set 2020
Modificato: Bruno Luong il 14 Set 2020
Just replace the RHS as I hint in my answer with "% = [0 0; 0 0]"
A(:, sub2ind(s(2:3),[2 3],[1 2])) = [[-1;-2], [-1;-2]]

Accedi per commentare.

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