# Selecting multiple array elements

3 views (last 30 days)
reincornator on 5 Jul 2022
Commented: reincornator on 5 Jul 2022
Hi.
n = 10;
A = rand(n);
B = A;
k = [1 1; 2 3; 4 5; 1 8; 8 6];
A(k(1,1),k(1,2))= 1;
A(k(2,1),k(2,2))= 1;
A(k(3,1),k(3,2))= 1;
A(k(4,1),k(4,2))= 1;
A(k(5,1),k(5,2))= 1;
B(k(:,1),k(:,2))=1;
isequal(A,B)
ans = logical
0
How can I assign a value of 1 to elements from array B with coordinates k using a single command?

Fangjun Jiang on 5 Jul 2022
Edited: Fangjun Jiang on 5 Jul 2022
n = 10;
A = zeros(n);
B = A;
k = [1 1; 2 3; 4 5; 1 8; 8 6];
A(k(1,1),k(1,2))= 1;
A(k(2,1),k(2,2))= 1;
A(k(3,1),k(3,2))= 1;
A(k(4,1),k(4,2))= 1;
A(k(5,1),k(5,2))= 1
A = 10×10
1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
B(sub2ind(size(A),k(:,1),k(:,2)))=1
B = 10×10
1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
isequal(A,B)
ans = logical
1
reincornator on 5 Jul 2022
Спасибо.

R2022a

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