Mercurial > hg > octave-lyh
annotate scripts/plot/feather.m @ 8874:bd1b1fe9c6e9 ss-3-1-53
bump version info for snapshot
| author | John W. Eaton <jwe@octave.org> |
|---|---|
| date | Wed, 25 Feb 2009 18:35:47 -0500 |
| parents | a2d9f325b65a |
| children | eb63fbe60fab |
| rev | line source |
|---|---|
| 7322 | 1 ## Copyright (C) 2007 David Bateman |
| 2 ## | |
| 3 ## This file is part of Octave. | |
| 4 ## | |
| 5 ## Octave is free software; you can redistribute it and/or modify it | |
| 6 ## under the terms of the GNU General Public License as published by | |
| 7 ## the Free Software Foundation; either version 3 of the License, or (at | |
| 8 ## your option) any later version. | |
| 9 ## | |
| 10 ## Octave is distributed in the hope that it will be useful, but | |
| 11 ## WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 ## General Public License for more details. | |
| 14 ## | |
| 15 ## You should have received a copy of the GNU General Public License | |
| 16 ## along with Octave; see the file COPYING. If not, see | |
| 17 ## <http://www.gnu.org/licenses/>. | |
| 18 | |
| 19 ## -*- texinfo -*- | |
| 20 ## @deftypefn {Function File} {} feather (@var{u}, @var{v}) | |
| 21 ## @deftypefnx {Function File} {} feather (@var{z}) | |
| 22 ## @deftypefnx {Function File} {} feather (@dots{}, @var{style}) | |
| 23 ## @deftypefnx {Function File} {} feather (@var{h}, @dots{}) | |
| 24 ## @deftypefnx {Function File} {@var{h} =} feather (@dots{}) | |
| 25 ## | |
| 26 ## Plot the @code{(@var{u}, @var{v})} components of a vector field emanating | |
| 27 ## from equidistant points on the x-axis. If a single complex argument | |
| 28 ## @var{z} is given, then @code{@var{u} = real (@var{z})} and | |
| 29 ## @code{@var{v} = imag (@var{z})}. | |
| 30 ## | |
| 31 ## The style to use for the plot can be defined with a line style @var{style} | |
| 32 ## in a similar manner to the line styles used with the @code{plot} command. | |
| 33 ## | |
| 34 ## The optional return value @var{h} provides a list of handles to the | |
| 35 ## the parts of the vector field (body, arrow and marker). | |
| 36 ## | |
| 37 ## @example | |
| 38 ## @group | |
| 39 ## phi = [0 : 15 : 360] * pi / 180; | |
| 40 ## feather (sin (phi), cos (phi)) | |
| 41 ## @end group | |
| 42 ## @end example | |
| 43 ## | |
| 44 ## @seealso{plot, quiver, compass} | |
| 45 ## @end deftypefn | |
| 46 | |
| 47 function retval = feather (varargin) | |
| 48 | |
| 49 [h, varargin, nargin] = __plt_get_axis_arg__ ("feather", varargin{:}); | |
| 50 | |
| 51 arrowsize = 0.25; | |
| 52 firstnonnumeric = Inf; | |
| 53 for i = 1:nargin | |
| 54 if (! isnumeric (varargin{i})) | |
| 55 firstnonnumeric = i; | |
| 56 break; | |
| 57 endif | |
| 58 endfor | |
| 59 | |
| 60 if (nargin < 2 || firstnonnumeric < 2) | |
| 61 ioff = 2; | |
| 62 z = varargin {1} (:) .'; | |
| 63 u = real (z); | |
| 64 v = imag (z); | |
| 65 else | |
| 66 ioff = 3; | |
| 67 u = varargin {1} (:) .'; | |
| 68 v = varargin {2} (:) .'; | |
| 69 endif | |
| 70 | |
| 71 line_spec = "b-"; | |
| 72 while (ioff <= nargin) | |
| 73 arg = varargin{ioff++}; | |
|
7768
a2d9f325b65a
Use isschar instead of deprecated isstr
Rafael Laboissiere <rafael@debian.org>
parents:
7322
diff
changeset
|
74 if ((ischar (arg) || iscell (arg)) && ! have_line_spec) |
| 7322 | 75 [linespec, valid] = __pltopt__ ("feather", arg, false); |
| 76 if (valid) | |
| 77 line_spec = arg; | |
| 78 break; | |
| 79 else | |
| 80 error ("feather: invalid linespec"); | |
| 81 endif | |
| 82 else | |
| 83 error ("feather: unrecognized argument"); | |
| 84 endif | |
| 85 endwhile | |
| 86 | |
| 87 ## Matlab draws feather plots, with the arrow head as one continous | |
| 88 ## line, and each arrow separately. This is completely different than | |
| 89 ## quiver and quite ugly. | |
| 90 n = length (u); | |
| 91 xend = [1 : n] + u; | |
| 92 xtmp = [1 : n] + u .* (1 - arrowsize); | |
| 93 yend = v; | |
| 94 ytmp = v .* (1 - arrowsize); | |
| 95 x = [[1 : n]; xend; xtmp - v * arrowsize; xend; ... | |
| 96 xtmp + v * arrowsize]; | |
| 97 y = [zeros(1, n); yend; ytmp + u * arrowsize / 3; yend; ... | |
| 98 ytmp - u * arrowsize / 3]; | |
| 99 | |
| 100 oldh = gca (); | |
| 101 unwind_protect | |
| 102 axes (h); | |
| 103 newplot (); | |
| 104 hlist = plot (h, x, y, line_spec, [1, n], [0, 0], line_spec); | |
| 105 unwind_protect_cleanup | |
| 106 axes (oldh); | |
| 107 end_unwind_protect | |
| 108 | |
| 109 if (nargout > 0) | |
| 110 retval = hlist; | |
| 111 endif | |
| 112 | |
| 113 endfunction | |
| 114 | |
| 115 %!demo | |
| 116 %! phi = [0 : 15 : 360] * pi / 180; | |
| 117 %! feather (sin (phi), cos (phi)) |