update packages

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

diff --git a/octave_packages/m/plot/quiver.m b/octave_packages/m/plot/quiver.m
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+## Copyright (C) 2007-2012 David Bateman
+##
+## 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} {} quiver (@var{u}, @var{v})
+## @deftypefnx {Function File} {} quiver (@var{x}, @var{y}, @var{u}, @var{v})
+## @deftypefnx {Function File} {} quiver (@dots{}, @var{s})
+## @deftypefnx {Function File} {} quiver (@dots{}, @var{style})
+## @deftypefnx {Function File} {} quiver (@dots{}, 'filled')
+## @deftypefnx {Function File} {} quiver (@var{h}, @dots{})
+## @deftypefnx {Function File} {@var{h} =} quiver (@dots{})
+##
+## Plot the @code{(@var{u}, @var{v})} components of a vector field in
+## an @code{(@var{x}, @var{y})} meshgrid.  If the grid is uniform, you can
+## specify @var{x} and @var{y} as vectors.
+##
+## If @var{x} and @var{y} are undefined they are assumed to be
+## @code{(1:@var{m}, 1:@var{n})} where @code{[@var{m}, @var{n}] =
+## size(@var{u})}.
+##
+## The variable @var{s} is a scalar defining a scaling factor to use for
+## the arrows of the field relative to the mesh spacing.  A value of 0
+## disables all scaling.  The default value is 1.
+##
+## 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.
+## If a marker is specified then markers at the grid points of the vectors are
+## printed rather than arrows.  If the argument 'filled' is given then the
+## markers as filled.
+##
+## The optional return value @var{h} is a graphics handle to a quiver object.
+## A quiver object regroups the components of the quiver plot (body, arrow,
+## and marker), and allows them to be changed together.
+##
+## @example
+## @group
+## [x, y] = meshgrid (1:2:20);
+## h = quiver (x, y, sin (2*pi*x/10), sin (2*pi*y/10));
+## set (h, "maxheadsize", 0.33);
+## @end group
+## @end example
+##
+## @seealso{plot}
+## @end deftypefn
+
+function retval = quiver (varargin)
+
+  [h, varargin, nargin] = __plt_get_axis_arg__ ("quiver", varargin{:});
+
+  if (nargin < 2)
+    print_usage ();
+  else
+    oldh = gca ();
+    unwind_protect
+      axes (h);
+      newplot ();
+      tmp = __quiver__ (h, 0, varargin{:});
+    unwind_protect_cleanup
+      axes (oldh);
+    end_unwind_protect
+  endif
+
+  if (nargout > 0)
+    retval = tmp;
+  endif
+
+endfunction
+
+
+%!demo
+%! clf
+%! [x,y] = meshgrid (1:2:20);
+%! h = quiver (x,y, sin (2*pi*x/10), sin (2*pi*y/10));
+%! set (h, "maxheadsize", 0.33);
+
+%!demo
+%! clf
+%! axis ("equal");
+%! x = linspace (0,3,80);
+%! y = sin (2*pi*x);
+%! theta = 2*pi*x + pi/2;
+%! quiver (x, y, sin (theta)/10, cos (theta)/10);
+%! hold on; plot(x,y,"r"); hold off;
+