Find the largest index of the minimum in Matlab

Question

I have an array of positive numbers and there are some duplicates. I want to find the largest index of the minimum value.

For example, if a=[2, 3, 1, 1, 4, 1, 3, 2, 1, 5, 5] then [i, v] = min(a) returns i=3 , however I want i=9 .

Answer 1

Using find and min .

A = [2, 3, 1, 1, 4, 1, 3, 2, 1, 5, 5];
minA = min(A);
maxIndex = max(find(A==minA));

min get the minimun value, and find return de index of values that meet the condition A==minA . max return de maximun index.

Answer 2

Here's a different idea, which only requires one function, sort :

[~,y] =  sort(a,'descend');
i = y(end)

ans =

     9

Answer 3

You can use imreginalmin as well with time complexity O(n) :

largestMinIndex = find(imregionalmin(A),1,'last');