How to get MATLAB to display the index of the minimum value in a 2D array?

Question

I'm trying to write a script in MATLAB that finds the location of the minimum value of a 2D array of numbers. I am certain there is only 1 minimum in this array, so having multiple locations in the array with the same minimum value is not an issue. I can find the minimum value of the array, but in a 30x30 array, I would like to know which row and column that minimum value is in.

Answer 1

As an alternative version, combine min to get the minimum value and find to return the index, if you've already calculated the minimum then just use find.

>> a=magic(30);
>> [r,c]=find(a==min(min(a)))

r =
     1
c =
     8

Or depending on how you want to use the location information you may want to define it with a logical array instead, in which case logical addressing can be used to give you a truth table.

>> a=magic(30);
>> locn=(a==min(min(a)));

Answer 2

You could reshape the matrix to a vector, find the index of the minimum using MIN and then convert this linear index into a matrix index:

>> x = randi(5, 5)

x =

     5     4     4     2     4
     4     2     4     5     5
     3     1     3     4     3
     3     4     2     5     1
     2     4     5     3     5

>> [value, index] = min(reshape(x, numel(x), 1));
>> [i,j] = ind2sub(size(x), index)

i =

     3


j =

     2