矩阵中的最大值的指标

Question

Let's say I have the following matrix:

 j = 
 1   2   3   4  
 1   2   3   4  
 5   6   7   8  
 5   6   7   8

I would like to get back the following matrix:

z =  
3 4  
4 4 

My experience with the max command hasn't yielded a result that resembles z, it appears that the max function turns the argument into a column vector.

Answer 1

It appears you want the row and column indices of all occurrences of the maximum computed across all dimensions (ie the maximum is a single value, which possibly appears in several entries). Then:

[rows, cols] = find(j==max(j(:)));
result = [rows cols];