Find the last position of maximum value in a Matrix

Hello, I try to find the position and the value of a maximum in a Matrix (or in a vektor). There are several positions for the maximas and the function [C,I] = max(...) just return the first, but I need the last position. exists a method to find the last maximum?

Answer 1

[Wayne King]

You can use find() with the 'last' argument:

    x = randi([1 10],100,1);
    maxval = max(x);
    I = find(x==maxval,1,'last');

Or for a matrix:

     X = randi([1 10],20,20);
     maxval = max(X(:));
     [I,J] = find(X==maxval,1,'last');

Answer 2

[Azzi Abdelmalek]

x=[1 2 3 0 3];
[ii,jj]=max(fliplr(x));
idx=numel(x)-jj+1

Answer 3

[Bradley Stiritz]

@Wayne, is your solution vulnerable to rounding error, with floating-point input? In general, might it not be safer to use something like the following--?

epsilon = 0.0001;
I = find(abs(x-maxval)<epsilon,1,'last');

@Azzi, very clever solution but is it not hard-coded for row vectors? In order to handle column vectors as well, shouldn't the 2nd line be something like the following--?

[ii,jj]=max(fliplr(x(:)'));