CODEWITHSUNDEEP
matlabmatrix
João Paulo
João Paulo

Reputation: 6670

Get specific points from matrix with one command

Supposing I have this matrix:

>> m = magic(4)

m =

    16     2     3    13
     5    11    10     8
     9     7     6    12
     4    14    15     1

and I want do access these positions x1 = [1;3] and x2 = [4;3], I mean, I want a result like this: [13; 6], the [x1(1); x2(1)] and [x1(2); x2(2)] positions. x1 and x2 can have any size. I tried doing m(x1, x2), but did not work... Is there a way to achieve this with one command?

Upvotes: 0

Views: 46

Answers (1)

Zizy Archer
Zizy Archer

Reputation: 1390

You can get multiple values with linear indices, say in your case m([13, 6]);

To get linear indices, use sub2ind(size(m), x1, x2); which will generate [13,6] in your case.

Now just glue them together to get the one-liner: 

out = m(sub2ind(size(m), x1, x2));

Upvotes: 1

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