## Copyright (C) 1996, 1997, 1998, 2000, 2002, 2005, 2007 Kurt Hornik
##
## This file is part of Octave.
##
## Octave 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 3 of the License, or (at
## your option) any later version.
##
## Octave 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 Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {} empirical_inv (@var{x}, @var{data})
## For each element of @var{x}, compute the quantile (the inverse of the
## CDF) at @var{x} of the empirical distribution obtained from the
## univariate sample @var{data}.
## @end deftypefn

## Author: KH <Kurt.Hornik@wu-wien.ac.at>
## Description: Quantile function of the empirical distribution

function inv = empirical_inv (x, data)

  if (nargin != 2)
    print_usage ();
  endif

  if (! isvector (data))
    error ("empirical_inv: data must be a vector");
  endif

  inv = discrete_inv (x, data, ones (size (data)) / length (data));

endfunction