## Copyright (C) 1995, 1996, 1997  Friedrich Leisch
## 
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2, or (at your option)
## any later version.
## 
## This program is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details. 
## 
## You should have received a copy of the GNU General Public License
## along with this file.  If not, write to the Free Software Foundation,
## 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

## usage:  run_count (x, n)
##
## Counts the upward runs in the columns of x of length 1, 2, ... n-1
## and >= n.

## Author:  FL <Friedrich.Leisch@ci.tuwien.ac.at>
## Description:  Count upward runs

function retval = run_count (x, n)
  
  [xr, xc] = size(x);
  
  tmp = zeros (xr,xc);
  retval = zeros (n, xc);
  
  for j = 1 : xc
    run = 1;
    count = 1;

    for k = 2 : xr

      if x(k, j) < x(k-1, j)
	tmp(run, j) = count;
	run = run + 1;
	count = 0;
      endif
    
      count = count + 1;

    endfor

    tmp(run, j) = count;
  
  endfor
  
  for k=1 : (n-1)
    retval(k, :) = sum (tmp == k);
  endfor
  retval(n, :) = sum (tmp >= n);
  
endfunction