index of max element of a 4-D matrix

[Tim Rueth]

I am currently using a for-loop to parse through a 4-D matrix to find the index of the maximum-value element.  I'm sure this can be done much simpler using commands like max() and find().  Conceptually, I'd like to just say:

 

max_idx = find(max(matrix_4d))

 

but I know this doesn't work because of how max() finds the max of each column, and returns a matrix itself.  So, maybe something like:

 

[max_matrix idx_matrix] = max(max(max(max(matrix_4d))))

 

This gives me the correct max value, but not the intended index, again, due to how the index is determined from each resulting max matrix.

 

Does anyone know a vectorized way of determining the index of the maximum-value element in a 4-D matrix that's faster than a for loop?

 

Thanks.