Mercurial > hg > octave-lyh
annotate scripts/plot/shrinkfaces.m @ 14620:cd375519eab0
doc: Periodic grammar check of documentation
* get_unsatisfied_deps.m, print.m, shrinkfaces.m, polyfit.m, splinefit.m,
chol.cc, rand.cc, sparse.cc: Improve docstrings.
| author | Rik <octave@nomad.inbox5.com> |
|---|---|
| date | Thu, 10 May 2012 22:08:18 -0700 |
| parents | 9546bb28648c |
| children | 1804d5422f61 |
| rev | line source |
|---|---|
| 14574 | 1 ## Copyright (C) 2012 Martin Helm |
| 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 -*- | |
|
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20 ## @deftypefn {Function File} {} shrinkfaces (@var{p}, @var{sf}) |
| 14574 | 21 ## @deftypefnx {Function File} {@var{nfv} =} shrinkfaces (@var{p}, @var{sf}) |
| 22 ## @deftypefnx {Function File} {@var{nfv} =} shrinkfaces (@var{fv}, @var{sf}) | |
| 23 ## @deftypefnx {Function File} {@var{nfv} =} shrinkfaces (@var{f}, @var{v}, @var{sf}) | |
| 24 ## @deftypefnx {Function File} {[@var{nf}, @var{nv}] =} shrinkfaces (@dots{}) | |
| 25 ## | |
| 26 ## Reduce the faces area for a given patch, structure or explicit faces | |
| 27 ## and points matrices by a scale factor @var{sf}. The structure | |
| 28 ## @var{fv} must contain the fields 'faces' and 'vertices'. If the | |
| 29 ## factor @var{sf} is omitted then a default of 0.3 is used. | |
| 30 ## | |
| 31 ## Given a patch handle as the first input argument and no output | |
| 32 ## parameters, perform the shrinking of the patch faces in place and | |
| 33 ## redraw the patch. | |
| 34 ## | |
| 35 ## If called with one output argument, return a structure with fields | |
| 36 ## 'faces', 'vertices', and 'facevertexcdata' containing the data after | |
| 37 ## shrinking which can then directly be used as an input argument for the | |
| 38 ## @command{patch} function. | |
| 39 ## | |
| 40 ## Performing the shrinking on faces which are not convex can lead to | |
| 41 ## undesired results. | |
| 42 ## | |
|
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doc: Periodic grammar check of documentation
Rik <octave@nomad.inbox5.com>
parents:
14574
diff
changeset
|
43 ## For example, |
| 14574 | 44 ## |
| 45 ## @example | |
| 46 ## @group | |
| 47 ## [phi r] = meshgrid (linspace (0, 1.5*pi, 16), linspace (1, 2, 4)); | |
| 48 ## tri = delaunay (phi(:), r(:)); | |
| 49 ## v = [r(:).*sin(phi(:)) r(:).*cos(phi(:))]; | |
| 50 ## clf () | |
| 51 ## p = patch ("Faces", tri, "Vertices", v, "FaceColor", "none"); | |
| 52 ## fv = shrinkfaces (p); | |
| 53 ## patch (fv) | |
| 54 ## axis equal | |
| 55 ## grid on | |
| 56 ## @end group | |
| 57 ## @end example | |
| 58 ## | |
| 59 ## @noindent | |
| 60 ## draws a triangulated 3/4 circle and the corresponding shrinked | |
| 61 ## version. | |
| 62 ## @seealso{patch} | |
| 63 ## @end deftypefn | |
| 64 | |
| 65 ## Author: Martin Helm <martin@mhelm.de> | |
| 66 | |
| 67 function [nf, nv] = shrinkfaces (varargin) | |
| 68 | |
| 69 if (nargin < 1 || nargin > 3 || nargout > 2) | |
| 70 print_usage (); | |
| 71 endif | |
| 72 | |
| 73 sf = 0.3; | |
| 74 p = varargin{1}; | |
| 75 colors = []; | |
| 76 | |
| 77 if (ishandle (p) && nargin < 3) | |
| 78 faces = get (p, "Faces"); | |
| 79 vertices = get (p, "Vertices"); | |
| 80 colors = get (p, "FaceVertexCData"); | |
| 81 if (nargin == 2) | |
| 82 sf = varargin{2}; | |
| 83 endif | |
| 84 elseif (isstruct (p) && nargin < 3) | |
| 85 faces = p.faces; | |
| 86 vertices = p.vertices; | |
| 87 if (isfield (p, "facevertexcdata")) | |
| 88 colors = p.facevertexcdata; | |
| 89 endif | |
| 90 if (nargin == 2) | |
| 91 sf = varargin{2}; | |
| 92 endif | |
| 93 elseif (ismatrix (p) && nargin >= 2 && ismatrix (varargin{2})) | |
| 94 faces = p; | |
| 95 vertices = varargin{2}; | |
| 96 if (nargin == 3) | |
| 97 sf = varargin{3}; | |
| 98 endif | |
| 99 else | |
| 100 print_usage (); | |
| 101 endif | |
| 102 | |
| 103 if (! isscalar (sf) || sf <= 0) | |
| 104 error ("shrinkfaces: scale factor must be a positive scalar") | |
| 105 endif | |
| 106 | |
| 107 n = size (vertices, 2); | |
| 108 if (n < 2 || n > 3) | |
| 109 error ("shrinkfaces: only 2D and 3D patches are supported") | |
| 110 endif | |
| 111 | |
| 112 m = size (faces, 2); | |
| 113 if (m < 3) | |
| 114 error ("shrinkfaces: faces must consist of at least 3 vertices") | |
| 115 endif | |
| 116 | |
| 117 v = vertices(faces'(:), :); | |
| 118 if (isempty (colors) || size (colors, 1) == size (faces, 1)) | |
| 119 c = colors; | |
| 120 elseif (size (colors, 1) == size (vertices, 1)) | |
| 121 c = colors(faces'(:), :); | |
| 122 else | |
| 123 ## Discard inconsistent color data. | |
| 124 c = []; | |
| 125 endif | |
| 126 sv = size (v, 1); | |
| 127 ## we have to deal with a probably very large number of vertices, so | |
| 128 ## use sparse we use as midpoint (1/m, ..., 1/m) in generalized | |
| 129 ## barycentric coordinates. | |
| 130 midpoints = full (kron ( speye (sv / m), ones (m, m) / m) * sparse (v)); | |
| 131 v = sqrt (sf) * (v - midpoints) + midpoints; | |
| 132 f = reshape (1:sv, m, sv / m)'; | |
| 133 | |
| 134 switch (nargout) | |
| 135 case 0 | |
| 136 if (ishandle (p)) | |
| 137 set (p, "FaceVertexCData", [], "CData", []) # avoid exceptions | |
| 138 set (p, "Vertices", v, "Faces", f, "FaceVertexCData", c) | |
| 139 else | |
| 140 nf = struct ("faces", f, "vertices", v, "facevertexcdata", c); | |
| 141 endif | |
| 142 case 1 | |
| 143 nf = struct ("faces", f, "vertices", v, "facevertexcdata", c); | |
| 144 case 2 | |
| 145 nf = f; | |
| 146 nv = v; | |
| 147 endswitch | |
| 148 | |
| 149 endfunction | |
| 150 | |
| 151 %!demo | |
| 152 %! faces = [1 2 3; 1 3 4]; | |
| 153 %! vertices = [0 0; 1 0; 1 1; 0 1]; | |
| 154 %! clf () | |
| 155 %! patch ("Faces", faces, "Vertices", vertices, "FaceColor", "none") | |
| 156 %! fv = shrinkfaces (faces, vertices, 0.25); | |
| 157 %! patch (fv) | |
| 158 %! axis equal | |
| 159 | |
| 160 %!demo | |
| 161 %! faces = [1 2 3 4; 5 6 7 8]; | |
| 162 %! vertices = [0 0; 1 0; 2 1; 1 1; 2 0; 3 0; 4 1; 3.5 1]; | |
| 163 %! clf () | |
| 164 %! patch ("Faces", faces, "Vertices", vertices, "FaceColor", "none") | |
| 165 %! fv = shrinkfaces (faces, vertices, 0.25); | |
| 166 %! patch (fv) | |
| 167 %! axis equal | |
| 168 %! grid on | |
| 169 | |
| 170 %!demo | |
| 171 %! faces = [1 2 3 4]; | |
| 172 %! vertices = [-1 2; 0 0; 1 2; 0 1]; | |
| 173 %! clf () | |
| 174 %! patch ("Faces", faces, "Vertices", vertices, "FaceColor", "none") | |
| 175 %! fv = shrinkfaces (faces, vertices, 0.25); | |
| 176 %! patch (fv) | |
| 177 %! axis equal | |
| 178 %! grid on | |
| 179 %! title "faces which are not convex are clearly not allowed" | |
| 180 | |
| 181 %!demo | |
| 182 %! [phi r] = meshgrid (linspace (0, 1.5*pi, 16), linspace (1, 2, 4)); | |
| 183 %! tri = delaunay (phi(:), r(:)); | |
| 184 %! v = [r(:).*sin(phi(:)) r(:).*cos(phi(:))]; | |
| 185 %! clf () | |
| 186 %! p = patch ("Faces", tri, "Vertices", v, "FaceColor", "none"); | |
| 187 %! fv = shrinkfaces (p); | |
| 188 %! patch (fv) | |
| 189 %! axis equal | |
| 190 %! grid on | |
| 191 | |
| 192 %!demo | |
| 193 %! N = 10; # N intervals per axis | |
| 194 %! [x, y, z] = meshgrid (linspace (-4,4,N+1)); | |
| 195 %! val = x.^3 + y.^3 + z.^3; | |
| 196 %! fv = isosurface (x, y, z, val, 3, z); | |
| 197 %! | |
| 198 %! clf () | |
| 199 %! p = patch ("Faces", fv.faces, "Vertices", fv.vertices, "FaceVertexCData", ... | |
| 200 %! fv.facevertexcdata, "FaceColor", "interp", "EdgeColor", "black"); | |
| 201 %! axis equal | |
| 202 %! view (115, 30) | |
| 203 %! drawnow | |
| 204 %! shrinkfaces (p, 0.6); | |
| 205 | |
| 206 %!shared faces, vertices, nfv, nfv2 | |
| 207 %! faces = [1 2 3]; | |
| 208 %! vertices = [0 0 0; 1 0 0; 1 1 0]; | |
| 209 %! nfv = shrinkfaces (faces, vertices, 0.7); | |
| 210 %! nfv2 = shrinkfaces (nfv, 1/0.7); | |
| 211 %!assert (isfield (nfv, "faces")); | |
| 212 %!assert (isfield (nfv, "vertices")); | |
| 213 %!assert (size (nfv.faces), [1 3]); | |
| 214 %!assert (size (nfv.vertices), [3 3]); | |
| 215 %!assert (norm (nfv2.vertices - vertices), 0, 2*eps); |