Mercurial > octave
view libinterp/dldfcn/convhulln.cc @ 31211:8340137bb190
maint: Merge stable to default.
author | Markus Mützel <markus.muetzel@gmx.de> |
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date | Mon, 29 Aug 2022 13:58:00 +0200 |
parents | 83f9f8bda883 |
children | e88a07dec498 |
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//////////////////////////////////////////////////////////////////////// // // Copyright (C) 2000-2022 The Octave Project Developers // // See the file COPYRIGHT.md in the top-level directory of this // distribution or <https://octave.org/copyright/>. // // 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/>. // //////////////////////////////////////////////////////////////////////// /* 29. July 2000 - Kai Habel: first release 2002-04-22 Paul Kienzle * Use warning(...) function rather than writing to cerr 2006-05-01 Tom Holroyd * add support for consistent winding in all dimensions; output is * guaranteed to be simplicial. */ #if defined (HAVE_CONFIG_H) # include "config.h" #endif #include <limits> #include <string> #include "Array.h" #include "dMatrix.h" #include "oct-locbuf.h" #include "unwind-prot.h" #include "defun-dld.h" #include "error.h" #include "errwarn.h" #include "ov.h" #if defined (HAVE_QHULL) # include "oct-qhull.h" # if defined (NEED_QHULL_R_VERSION) char qh_version[] = "convhulln.oct 2007-07-24"; # endif static void free_qhull_memory (qhT *qh) { qh_freeqhull (qh, ! qh_ALL); int curlong, totlong; qh_memfreeshort (qh, &curlong, &totlong); if (curlong || totlong) warning ("convhulln: did not free %d bytes of long memory (%d pieces)", totlong, curlong); } static bool octave_qhull_dims_ok (octave_idx_type dim, octave_idx_type n, const char *who) { if (sizeof (octave_idx_type) > sizeof (int)) { int maxval = std::numeric_limits<int>::max (); if (dim > maxval || n > maxval) error ("%s: dimension too large for Qhull", who); } return true; } #endif OCTAVE_NAMESPACE_BEGIN DEFUN_DLD (convhulln, args, nargout, doc: /* -*- texinfo -*- @deftypefn {} {@var{h} =} convhulln (@var{pts}) @deftypefnx {} {@var{h} =} convhulln (@var{pts}, @var{options}) @deftypefnx {} {[@var{h}, @var{v}] =} convhulln (@dots{}) Compute the convex hull of the set of points @var{pts}. @var{pts} is a matrix of size [n, dim] containing n points in a space of dimension dim. The hull @var{h} is an index vector into the set of points and specifies which points form the enclosing hull. An optional second argument, which must be a string or cell array of strings, contains options passed to the underlying qhull command. See the documentation for the Qhull library for details @url{http://www.qhull.org/html/qh-quick.htm#options}. The default options depend on the dimension of the input: @itemize @item 2D, 3D, 4D: @var{options} = @code{@{"Qt"@}} @item 5D and higher: @var{options} = @code{@{"Qt", "Qx"@}} @end itemize If @var{options} is not present or @code{[]} then the default arguments are used. Otherwise, @var{options} replaces the default argument list. To append user options to the defaults it is necessary to repeat the default arguments in @var{options}. Use a null string to pass no arguments. If the second output @var{v} is requested the volume of the enclosing convex hull is calculated. @seealso{convhull, delaunayn, voronoin} @end deftypefn */) { #if defined (HAVE_QHULL) int nargin = args.length (); if (nargin < 1 || nargin > 2) print_usage (); octave_value_list retval; Matrix points (args(0).matrix_value ()); const octave_idx_type dim = points.columns (); const octave_idx_type num_points = points.rows (); if (! octave_qhull_dims_ok (dim, num_points, "convhulln")) return retval; points = points.transpose (); std::string options; if (dim <= 4) options = " Qt"; else options = " Qt Qx"; if (nargin == 2) { if (args(1).is_string ()) options = ' ' + args(1).string_value (); else if (args(1).isempty ()) ; // Use default options. else if (args(1).iscellstr ()) { options = ""; Array<std::string> tmp = args(1).cellstr_value (); for (octave_idx_type i = 0; i < tmp.numel (); i++) options += ' ' + tmp(i); } else error ("convhulln: OPTIONS must be a string, cell array of strings, or empty"); } boolT ismalloc = false; // Set the outfile pointer to stdout for status information. FILE *outfile = nullptr; FILE *errfile = stderr; qhT context = { }; qhT *qh = &context; std::string cmd = "qhull" + options; int exitcode = qh_new_qhull (qh, dim, num_points, points.fortran_vec (), ismalloc, &cmd[0], outfile, errfile); unwind_action free_memory ([qh] () { free_qhull_memory (qh); }); if (exitcode) error ("convhulln: qhull failed"); bool nonsimp_seen = false; octave_idx_type nf = qh->num_facets; Matrix idx (nf, dim + 1); facetT *facet; octave_idx_type i = 0; FORALLfacets { octave_idx_type j = 0; if (! (nonsimp_seen || facet->simplicial || qh->hull_dim == 2)) { nonsimp_seen = true; if (cmd.find ("QJ") != std::string::npos) // Should never happen with QJ. error ("convhulln: qhull failed: option 'QJ' returned non-simplicial facet"); } if (dim == 3) { setT *vertices = qh_facet3vertex (qh, facet); vertexT *vertex, **vertexp; FOREACHvertex_ (vertices) idx(i, j++) = 1 + qh_pointid(qh, vertex->point); qh_settempfree (qh, &vertices); } else { if (facet->toporient ^ qh_ORIENTclock) { vertexT *vertex, **vertexp; FOREACHvertex_ (facet->vertices) idx(i, j++) = 1 + qh_pointid(qh, vertex->point); } else { vertexT *vertex, **vertexp; FOREACHvertexreverse12_ (facet->vertices) idx(i, j++) = 1 + qh_pointid(qh, vertex->point); } } if (j < dim) warning ("convhulln: facet %" OCTAVE_IDX_TYPE_FORMAT " only has %" OCTAVE_IDX_TYPE_FORMAT " vertices", i, j); i++; } // Remove extra dimension if all facets were simplicial. if (! nonsimp_seen) idx.resize (nf, dim, 0.0); if (nargout == 2) { // Calculate volume of convex hull, taken from qhull src/geom2.c. realT area; realT dist; FORALLfacets { if (! facet->normal) continue; if (facet->upperdelaunay && qh->ATinfinity) continue; facet->f.area = area = qh_facetarea (qh, facet); facet->isarea = True; if (qh->DELAUNAY) { if (facet->upperdelaunay == qh->UPPERdelaunay) qh->totarea += area; } else { qh->totarea += area; qh_distplane (qh, qh->interior_point, facet, &dist); qh->totvol += -dist * area / qh->hull_dim; } } retval(1) = octave_value (qh->totvol); } retval(0) = idx; return retval; #else octave_unused_parameter (args); octave_unused_parameter (nargout); err_disabled_feature ("convhulln", "Qhull"); #endif } /* %!testif HAVE_QHULL %! cube = [0 0 0;1 0 0;1 1 0;0 1 0;0 0 1;1 0 1;1 1 1;0 1 1]; %! [h, v] = convhulln (cube, "Qt"); %! assert (size (h), [12 3]); %! h = sortrows (sort (h, 2), [1:3]); %! assert (h, %! [1 2 4; 1 2 6; 1 4 8; 1 5 6; 1 5 8; 2 3 4; 2 3 7; 2 6 7; 3 4 7; 4 7 8; 5 6 7; 5 7 8]); %! assert (v, 1, 10*eps); %! [h2, v2] = convhulln (cube); # Test default option = "Qt" %! assert (size (h2), size (h)); %! h2 = sortrows (sort (h2, 2), [1:3]); %! assert (h2, h); %! assert (v2, v, 10*eps); %!testif HAVE_QHULL %! cube = [0 0 0;1 0 0;1 1 0;0 1 0;0 0 1;1 0 1;1 1 1;0 1 1]; %! [h, v] = convhulln (cube, "QJ"); %! assert (size (h), [12 3]); %! assert (sortrows (sort (h, 2), [1:3]), %! [1 2 4; 1 2 5; 1 4 5; 2 3 4; 2 3 6; 2 5 6; 3 4 8; 3 6 7; 3 7 8; 4 5 8; 5 6 8; 6 7 8]); %! assert (v, 1.0, 1e6*eps); %!testif HAVE_QHULL %! tetrahedron = [1 1 1;-1 -1 1;-1 1 -1;1 -1 -1]; %! [h, v] = convhulln (tetrahedron); %! h = sortrows (sort (h, 2), [1 2 3]); %! assert (h, [1 2 3;1 2 4; 1 3 4; 2 3 4]); %! assert (v, 8/3, 10*eps); %!testif HAVE_QHULL %! triangle = [0 0; 1 1; 1 0; 1 2]; %! h = convhulln (triangle); %! assert (size (h), [3 2]); */ OCTAVE_NAMESPACE_END