Function that returns index of first occurrence of largest value for each column of matrix

Hi,

I would like to write a function that returns the index of the first occurrence of the largest value in each column of a matrix. Ideally it would also have the flexibility to specify the row or the columns as the search direction, and/or could work for N-dimensional matrices.

I thought that the following would work:

 function [ maxind ] = findmax( indata,k,varargin )

      maxind  =   find(indata == max(indata),k,varargin(:));

 end

But, when I pass a matrix into the function I get the following error:

 maxind = findmax(indata,1,'first')

 Undefined function 'find' for input arguments of type 'cell'.

 Error in findmax (line 6)
 maxind  =   find(indata == max(indata),k,varargin(:));

Answer 1

[Cedric Wannaz]

Another solution, almost trivial, is just to use the second output of MAX, which is the index of the first occurrence, and to flip along dim if there is a 3rd input arg. not starting with 'f'.

 function maxInds = findMax( A, dim, direction )
    if nargin < 2
       dim = 1 ;
    end
    if nargin < 3
       direction = 'f' ;
    end
    if direction(1) == 'f'
       [~, maxInds] = max( A, [], dim ) ;
    else
       [~, maxInds] = max( flip( A, dim ), [], dim ) ;
       maxInds = size( A, dim ) + 1 - maxInds ;
    end
 end