1######################################################################## 2## 3## Copyright (C) 2007-2021 The Octave Project Developers 4## 5## See the file COPYRIGHT.md in the top-level directory of this 6## distribution or <https://octave.org/copyright/>. 7## 8## This file is part of Octave. 9## 10## Octave is free software: you can redistribute it and/or modify it 11## under the terms of the GNU General Public License as published by 12## the Free Software Foundation, either version 3 of the License, or 13## (at your option) any later version. 14## 15## Octave is distributed in the hope that it will be useful, but 16## WITHOUT ANY WARRANTY; without even the implied warranty of 17## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18## GNU General Public License for more details. 19## 20## You should have received a copy of the GNU General Public License 21## along with Octave; see the file COPYING. If not, see 22## <https://www.gnu.org/licenses/>. 23## 24######################################################################## 25 26## -*- texinfo -*- 27## @deftypefn {} {} triplot (@var{tri}, @var{x}, @var{y}) 28## @deftypefnx {} {} triplot (@var{tri}, @var{x}, @var{y}, @var{linespec}) 29## @deftypefnx {} {@var{h} =} triplot (@dots{}) 30## Plot a 2-D triangular mesh. 31## 32## @var{tri} is typically the output of a Delaunay triangulation over the 33## grid of @var{x}, @var{y}. Every row of @var{tri} represents one triangle 34## and contains three indices into [@var{x}, @var{y}] which are the 35## vertices of the triangles in the x-y plane. 36## 37## The linestyle to use for the plot can be defined with the argument 38## @var{linespec} of the same format as the @code{plot} command. 39## 40## The optional return value @var{h} is a graphics handle to the created 41## patch object. 42## @seealso{plot, trimesh, trisurf, delaunay} 43## @end deftypefn 44 45function h = triplot (tri, x, y, varargin) 46 47 if (nargin < 3) 48 print_usage (); 49 endif 50 51 idx = tri(:, [1, 2, 3, 1]).'; 52 nt = rows (tri); 53 htmp = plot ([x(idx); NaN(1, nt)](:), 54 [y(idx); NaN(1, nt)](:), varargin{:}); 55 56 if (nargout > 0) 57 h = htmp; 58 endif 59 60endfunction 61 62 63%!demo 64%! clf; 65%! old_state = rand ("state"); 66%! restore_state = onCleanup (@() rand ("state", old_state)); 67%! rand ("state", 2); 68%! N = 20; 69%! x = rand (N, 1); 70%! y = rand (N, 1); 71%! tri = delaunay (x, y); 72%! triplot (tri, x, y); 73%! title ("triplot() of random 2-D Delaunay triangulation"); 74