update packages

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

diff --git a/octave_packages/m/plot/sphere.m b/octave_packages/m/plot/sphere.m
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+## Copyright (C) 2007-2012 Michael Goffioul
+##
+## 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{x}, @var{y}, @var{z}] =} sphere (@var{n})
+## @deftypefnx {Function File} {} sphere (@var{h}, @dots{})
+## Generate three matrices in @code{meshgrid} format, such that
+## @code{surf (@var{x}, @var{y}, @var{z})} generates a unit sphere.
+## The matrices of @code{@var{n}+1}-by-@code{@var{n}+1}.  If @var{n} is
+## omitted then a default value of 20 is assumed.
+##
+## Called with no return arguments, @code{sphere} call directly
+## @code{surf (@var{x}, @var{y}, @var{z})}.  If an axes handle is passed
+## as the first argument, the surface is plotted to this set of axes.
+## @seealso{peaks}
+## @end deftypefn
+
+function [xx, yy, zz] = sphere (varargin)
+
+  [h, varargin, nargin] = __plt_get_axis_arg__ ((nargout > 0), "sphere",
+                                                varargin{:});
+  if (nargin > 1)
+    print_usage ();
+  elseif (nargin == 1)
+    n = varargin{1};
+  else
+    n = 20;
+  endif
+
+  theta = linspace (0, 2*pi, n+1);
+  phi = linspace (-pi/2, pi/2, n+1);
+  [theta,phi] = meshgrid (theta, phi);
+
+  x = cos (phi) .* cos (theta);
+  y = cos (phi) .* sin (theta);
+  z = sin (phi);
+
+  if (nargout > 0)
+    xx = x;
+    yy = y;
+    zz = z;
+  else
+    surf (h, x, y, z);
+  endif
+
+endfunction