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view scripts/plot/draw/quiver.m @ 27919:1891570abac8
update Octave Project Developers copyright for the new year
In files that have the "Octave Project Developers" copyright notice,
update for 2020.
author | John W. Eaton <jwe@octave.org> |
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date | Mon, 06 Jan 2020 22:29:51 -0500 |
parents | b442ec6dda5c |
children | bd51beb6205e |
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## Copyright (C) 2007-2020 The Octave Project Developers ## ## See the file COPYRIGHT.md in the top-level directory of this distribution ## or <https://octave.org/COPYRIGHT.html/>. ## ## ## 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 ## <https://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {} {} quiver (@var{u}, @var{v}) ## @deftypefnx {} {} quiver (@var{x}, @var{y}, @var{u}, @var{v}) ## @deftypefnx {} {} quiver (@dots{}, @var{s}) ## @deftypefnx {} {} quiver (@dots{}, @var{style}) ## @deftypefnx {} {} quiver (@dots{}, "filled") ## @deftypefnx {} {} quiver (@var{hax}, @dots{}) ## @deftypefnx {} {@var{h} =} quiver (@dots{}) ## ## Plot a 2-D vector field with arrows. ## ## Plot the (@var{u}, @var{v}) components of a vector field at the grid points ## defined by (@var{x}, @var{y}). If the grid is uniform then @var{x} and ## @var{y} can be specified as vectors and @code{meshgrid} is used to create ## the 2-D grid. ## ## If @var{x} and @var{y} are not given they are assumed to be ## @code{(1:@var{m}, 1:@var{n})} where ## @code{[@var{m}, @var{n}] = size (@var{u})}. ## ## The optional input @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 1.0 will ## result in the longest vector exactly filling one grid square. A value of 0 ## disables all scaling. The default value is 0.9. ## ## The style to use for the plot can be defined with a line style @var{style} ## of the same format as the @code{plot} command. If a marker is specified ## then the markers are drawn at the origin of the vectors (which are the grid ## points defined by @var{x} and @var{y}). When a marker is specified, the ## arrowhead is not drawn. If the argument @qcode{"filled"} is given then the ## markers are filled. ## ## If the first argument @var{hax} is an axes handle, then plot into this axes, ## rather than the current axes returned by @code{gca}. ## ## 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: ## ## @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{quiver3, compass, feather, plot} ## @end deftypefn function h = quiver (varargin) [hax, varargin, nargin] = __plt_get_axis_arg__ ("quiver", varargin{:}); if (nargin < 2) print_usage (); endif oldfig = []; if (! isempty (hax)) oldfig = get (0, "currentfigure"); endif unwind_protect hax = newplot (hax); htmp = __quiver__ (hax, false, varargin{:}); ## FIXME: This should be moved into __quiver__ when problem with ## re-initialization of title object is fixed. if (! ishold ()) set (hax, "box", "on"); endif unwind_protect_cleanup if (! isempty (oldfig)) set (0, "currentfigure", oldfig); endif end_unwind_protect if (nargout > 0) h = htmp; endif endfunction %!demo %! clf; %! [x,y] = meshgrid (1:2:20); %! h = quiver (x,y, sin (2*pi*x/10), sin (2*pi*y/10)); %! title ("quiver() plot w/arrowheads (default)"); %!demo %! clf; %! [x,y] = meshgrid (1:2:20); %! h = quiver (x,y, sin (2*pi*x/10), sin (2*pi*y/10), "o"); %! title ("quiver() plot w/origin markers"); %!demo %! clf; %! [x,y] = meshgrid (1:2:20); %! h = quiver (x,y, sin (2*pi*x/10), sin (2*pi*y/10)); %! set (h, "marker", "o"); %! title ("quiver() plot w/origin markers and arrowheads"); %!demo %! clf; %! 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, 0.4); %! axis equal tight; %! hold on; plot (x,y,"r"); hold off; %! title ("quiver() with scaled arrows");