update packages

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

diff --git a/octave_packages/m/plot/pcolor.m b/octave_packages/m/plot/pcolor.m
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+## Copyright (C) 2007-2012 Kai Habel
+##
+## 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} {} pcolor (@var{x}, @var{y}, @var{c})
+## @deftypefnx {Function File} {} pcolor (@var{c})
+## Density plot for given matrices @var{x}, and @var{y} from @code{meshgrid} and
+## a matrix @var{c} corresponding to the @var{x} and @var{y} coordinates of
+## the mesh's vertices.  If @var{x} and @var{y} are vectors, then a typical
+## vertex
+## is (@var{x}(j), @var{y}(i), @var{c}(i,j)).  Thus, columns of @var{c}
+## correspond to different @var{x} values and rows of @var{c} correspond
+## to different @var{y} values.
+##
+## The @code{colormap} is scaled to the extents of @var{c}.
+## Limits may be placed on the color axis by the
+## command @code{caxis}, or by setting the @code{clim} property of the
+## parent axis.
+##
+## The face color of each cell of the mesh is determined by interpolating
+## the values of @var{c} for the cell's vertices.  Contrast this with
+## @code{imagesc} which renders one cell for each element of @var{c}.
+##
+## @code{shading} modifies an attribute determining the manner by which the
+## face color of each cell is interpolated from the values of @var{c},
+## and the visibility of the cells' edges.  By default the attribute is
+## "faceted", which renders a single color for each cell's face with the edge
+## visible.
+##
+## @var{h} is the handle to the surface object.
+##
+## @seealso{caxis, contour, meshgrid, imagesc, shading}
+## @end deftypefn
+
+## Author: Kai Habel <kai.habel@gmx.de>
+
+function h = pcolor (x, y, c)
+
+  newplot ();
+
+  if (nargin == 1)
+    c = x;
+    [nr, nc] = size(c);
+    z = zeros (nr, nc);
+    [x, y] = meshgrid (1:nc, 1:nr);
+  elseif (nargin == 3)
+    z = zeros (size (c));
+  else
+    print_usage ();
+  endif
+
+  tmp = surface (x, y, z, c);
+
+  ax = get (tmp, "parent");
+
+  set (tmp, "facecolor", "flat");
+  set (ax, "box", "on");
+
+  if (! ishold ())
+    set (ax, "view", [0, 90]);
+  endif
+
+  if (nargout > 0)
+    h = tmp;
+  endif
+
+endfunction
+
+%!demo
+%! clf
+%! [~,~,Z]=peaks;
+%! pcolor(Z);
+
+%!demo
+%! clf
+%! [X,Y,Z]=sombrero;
+%! [Fx,Fy] = gradient(Z);
+%! pcolor(X,Y,Fx+Fy);
+%! shading interp;