Index of minimum element of matrix

Question

How can I find the (i, j) index of the minimum element of a matrix?

For example:

M = [3 6 2; 5 5 9; 1 4 4];

I would want to get the output (3, 1).

score 6 · Answer 1 · answered Jul 30 '14 at 13:19

6

Try this:

M = [3 6 2; 5 5 9; 1 4 4];
[~, ind] = min(M(:));
[i, j] = ind2sub(size(M), ind);

answered Jul 30 '14 at 13:19

nicolas

score 1 · Answer 2 · answered Jul 30 '14 at 13:17

1

[r,c]=find(M==min(M(:)))

Hope this helps...

answered Jul 30 '14 at 13:17

lakshmen

Could possibly run into issues comparing floats here. – sco1 Jul 30 '14 at 13:43
1

@excaza I don't see why that would be a problem, `min` doesn't perform any calculations so it should return an exact match – Dan Jul 30 '14 at 13:57
@excaza - There should be no floating point compare issues. First you are retrieving the minimum floating point value from this array, then you're comparing **this exact** value that was extracted from this array to all of the other points in this array. This would only be an issue if you extracted a minimum, then performed some calculations on the matrix, and then tried to do a compare..... and I just basically regurgitated what Dan said, but I just wanted to put my two cents in. – rayryeng Aug 11 '14 at 22:40

score -1 · Answer 3 · answered Jul 30 '14 at 13:17

-1

[value,index] = min(M(:))

will give:

value = 1
index = 3

answered Jul 30 '14 at 13:17

Benoit_11

1

This is not what was asked, you could call `sub2ind` on your `index` value to get the correct answer though but this is a linear index when the OP asks for a subscript index – Dan Jul 30 '14 at 13:19
Oh damn you're right sorry about that I misread the question. – Benoit_11 Jul 30 '14 at 13:21

3 Answers3