## Copyright (C) 1995-2012 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} {} probit (@var{p})
## For each component of @var{p}, return the probit (the quantile of the
## standard normal distribution) of @var{p}.
## @end deftypefn

## Written by KH <Kurt.Hornik@wu-wien.ac.at> on 1995/02/04
## Description: Probit transformation

function y = probit (p)


  if (nargin != 1)
    print_usage ();
  endif

  y = stdnormal_inv (p);

endfunction

%!assert(probit([-1, 0, 0.5, 1, 2]), [NaN, -Inf, 0, Inf, NaN]);

%% Test input validation
%!error probit ()
%!error probit (1, 2)