update packages

[CreaPhase.git] / octave_packages / m / plot / meshgrid.m

diff --git a/octave_packages/m/plot/meshgrid.m b/octave_packages/m/plot/meshgrid.m
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+## Copyright (C) 1996-2012 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 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} {[@var{xx}, @var{yy}, @var{zz}] =} meshgrid (@var{x}, @var{y}, @var{z})
+## @deftypefnx {Function File} {[@var{xx}, @var{yy}] =} meshgrid (@var{x}, @var{y})
+## @deftypefnx {Function File} {[@var{xx}, @var{yy}] =} meshgrid (@var{x})
+## Given vectors of @var{x} and @var{y} and @var{z} coordinates, and
+## returning 3 arguments, return three-dimensional arrays corresponding
+## to the @var{x}, @var{y}, and @var{z} coordinates of a mesh.  When
+## returning only 2 arguments, return matrices corresponding to the
+## @var{x} and @var{y} coordinates of a mesh.  The rows of @var{xx} are
+## copies of @var{x}, and the columns of @var{yy} are copies of @var{y}.
+## If @var{y} is omitted, then it is assumed to be the same as @var{x},
+## and @var{z} is assumed the same as @var{y}.
+## @seealso{mesh, contour}
+## @end deftypefn
+
+## Author: jwe
+
+function [xx, yy, zz] = meshgrid (x, y, z)
+
+  if (nargin == 0 || nargin > 3)
+    print_usage ();
+  endif
+
+  if (nargin < 2)
+    y = x;
+  endif
+
+  ## Use repmat to ensure that the result values have the same type as
+  ## the arguments.
+
+  if (nargout < 3)
+    if (isvector (x) && isvector (y))
+      xx = repmat (x(:).', length (y), 1);
+      yy = repmat (y(:), 1, length (x));
+    else
+      error ("meshgrid: arguments must be vectors");
+    endif
+  else
+    if (nargin < 3)
+      z = y;
+    endif
+    if (isvector (x) && isvector (y) && isvector (z))
+       lenx = length (x);
+       leny = length (y);
+       lenz = length (z);
+       xx = repmat (repmat (x(:).', leny, 1), [1, 1, lenz]);
+       yy = repmat (repmat (y(:), 1, lenx), [1, 1, lenz]);
+       zz = reshape (repmat (z(:).', lenx*leny, 1)(:), leny, lenx, lenz);
+    else
+      error ("meshgrid: arguments must be vectors");
+    endif
+  endif
+
+endfunction
+
+%!test
+%! x = 1:2;
+%! y = 1:3;
+%! z = 1:4;
+%! [XX, YY, ZZ] = meshgrid (x, y, z);
+%! assert (size_equal (XX, YY, ZZ));
+%! assert (ndims (XX), 3);
+%! assert (size (XX), [3, 2, 4]);
+%! assert (XX(1) * YY(1) * ZZ(1), x(1) * y(1) * z(1));
+%! assert (XX(end) * YY(end) * ZZ(end), x(end) * y(end) * z(end));
+
+%!test
+%! x = 1:2;
+%! y = 1:3;
+%! [XX, YY] = meshgrid (x, y);
+%! assert (size_equal (XX, YY));
+%! assert (ndims (XX), 2);
+%! assert (size (XX), [3, 2]);
+%! assert (XX(1) * YY(1), x(1) * y(1));
+%! assert (XX(end) * YY(end), x(end) * y(end));
+
+%!test
+%! x = 1:3;
+%! [XX1, YY1] = meshgrid (x, x);
+%! [XX2, YY2] = meshgrid (x);
+%! assert (size_equal (XX1, XX2, YY1, YY2));
+%! assert (ndims (XX1), 2);
+%! assert (size (XX1), [3, 3]);
+%! assert (XX1, XX2);
+%! assert (YY1, YY2);
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