# Copyright (C) 1996 John W. Eaton
# 
# 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 2, 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, write to the Free
# Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

function [xx, yy] = meshgrid (x, y)

# usage: [xx, yy] = meshgrid (x, y)
#
# Given vectors of x and y coordinates, return two matrices corresponding
# to the x and y coordinates of a mesh.  The rows of xx are copies of x,
# and the columns of yy are copies of y.
#
# [xx, yy] = meshgrid (x) is an abbreviation for [xx, yy] = meshgrid (x, x).
#
# See also: plot, semilogx, semilogy, loglog, polar, mesh, meshdom, contour,
#           bar, stairs, gplot, gsplot, replot, xlabel, ylabel, title 

  if (nargin == 1)
    y = x;
  endif
  if (nargin > 0 && nargin < 3)
    if (is_vector (x) && is_vector (y))
      xlen = length (x);
      ylen = length (y);
      xx = zeros (ylen, xlen);
      yy = zeros (ylen, xlen);
      if (columns (x) == 1)
        x = x';
      endif
      if (rows (y) == 1)
        y = y';
      endif
      for i = 1:ylen
        xx(i,:) = x;
      endfor
      for i = 1:xlen
        yy(:,i) = y;
      endfor
    else
      error ("meshgrid: arguments must be vectors");
    endif
  else
    usage ("[xx, yy] = meshgrid (x, y)");
  endif

endfunction