update packages

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

diff --git a/octave_packages/m/plot/contour.m b/octave_packages/m/plot/contour.m
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+## Copyright (C) 1993-2012 Shai Ayal
+##
+## 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} {} contour (@var{z})
+## @deftypefnx {Function File} {} contour (@var{z}, @var{vn})
+## @deftypefnx {Function File} {} contour (@var{x}, @var{y}, @var{z})
+## @deftypefnx {Function File} {} contour (@var{x}, @var{y}, @var{z}, @var{vn})
+## @deftypefnx {Function File} {} contour (@dots{}, @var{style})
+## @deftypefnx {Function File} {} contour (@var{h}, @dots{})
+## @deftypefnx {Function File} {[@var{c}, @var{h}] =} contour (@dots{})
+## Plot level curves (contour lines) of the matrix @var{z}, using the
+## contour matrix @var{c} computed by @code{contourc} from the same
+## arguments; see the latter for their interpretation.  The set of
+## contour levels, @var{c}, is only returned if requested.  For example:
+##
+## @example
+## @group
+## x = 0:2;
+## y = x;
+## z = x' * y;
+## contour (x, y, z, 2:3)
+## @end group
+## @end example
+##
+## The style to use for the plot can be defined with a line style @var{style}
+## in a similar manner to the line styles used with the @code{plot} command.
+## Any markers defined by @var{style} are ignored.
+##
+## The optional input and output argument @var{h} allows an axis handle to
+## be passed to @code{contour} and the handles to the contour objects to be
+## returned.
+## @seealso{contourc, patch, plot}
+## @end deftypefn
+
+## Author: Shai Ayal <shaiay@users.sourceforge.net>
+
+function [c, h] = contour (varargin)
+
+  [xh, varargin] = __plt_get_axis_arg__ ("contour", varargin{:});
+
+  oldh = gca ();
+  unwind_protect
+    axes (xh);
+    newplot ();
+    [ctmp, htmp] = __contour__ (xh, "none", varargin{:});
+  unwind_protect_cleanup
+    axes (oldh);
+  end_unwind_protect
+
+  if (nargout > 0)
+    c = ctmp;
+    h = htmp;
+  endif
+
+endfunction
+
+%!demo
+%! clf ()
+%! [x, y, z] = peaks ();
+%! contour (x, y, z);
+
+%!demo
+%! clf ()
+%! [theta, r] = meshgrid (linspace (0, 2*pi, 64), linspace(0,1,64));
+%! [X, Y] = pol2cart (theta, r);
+%! Z = sin(2*theta).*(1-r);
+%! contour(X, Y, abs(Z), 10)
+
+%!demo
+%! clf ()
+%! x = linspace (-2, 2);
+%! [x, y] = meshgrid (x);
+%! z = sqrt (x.^2 + y.^2) ./ (x.^2 + y.^2+1);
+%! contourf (x, y, z, [0.4, 0.4])
+%! title ("The hole should be filled with the background color")
+