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source: branches/HeuristicLab.Analysis.AlgorithmBehavior/qhull-2012.1/src/libqhull/user.c @ 10621

Last change on this file since 10621 was 10207, checked in by ascheibe, 11 years ago

#1886 added a unit test for volume calculation and the qhull library

File size: 19.8 KB
RevLine 
[10207]1/*<html><pre>  -<a                             href="qh-user.htm"
2  >-------------------------------</a><a name="TOP">-</a>
3
4   user.c
5   user redefinable functions
6
7   see user2.c for qh_fprintf, qh_malloc, qh_free
8
9   see README.txt  see COPYING.txt for copyright information.
10
11   see libqhull.h for data structures, macros, and user-callable functions.
12
13   see user_eg.c, unix.c, and qhull_interface.cpp for examples.
14
15   see user.h for user-definable constants
16
17      use qh_NOmem in mem.h to turn off memory management
18      use qh_NOmerge in user.h to turn off facet merging
19      set qh_KEEPstatistics in user.h to 0 to turn off statistics
20
21   This is unsupported software.  You're welcome to make changes,
22   but you're on your own if something goes wrong.  Use 'Tc' to
23   check frequently.  Usually qhull will report an error if
24   a data structure becomes inconsistent.  If so, it also reports
25   the last point added to the hull, e.g., 102.  You can then trace
26   the execution of qhull with "T4P102".
27
28   Please report any errors that you fix to qhull@qhull.org
29
30   call_qhull is a template for calling qhull from within your application
31
32   if you recompile and load this module, then user.o will not be loaded
33   from qhull.a
34
35   you can add additional quick allocation sizes in qh_user_memsizes
36
37   if the other functions here are redefined to not use qh_print...,
38   then io.o will not be loaded from qhull.a.  See user_eg.c for an
39   example.  We recommend keeping io.o for the extra debugging
40   information it supplies.
41*/
42
43#include "qhull_a.h"
44
45#include <stdarg.h>
46
47/*-<a                             href="qh-user.htm#TOC"
48  >-------------------------------</a><a name="call_qhull">-</a>
49
50  qh_call_qhull( void )
51    template for calling qhull from inside your program
52    remove #if 0, #endif to compile
53
54  returns:
55    exit code(see qh_ERR... in libqhull.h)
56    all memory freed
57
58  notes:
59    This can be called any number of times.
60
61  see:
62    qh_call_qhull_once()
63
64*/
65#if 0
66{
67  int dim;                  /* dimension of points */
68  int numpoints;            /* number of points */
69  coordT *points;           /* array of coordinates for each point */
70  boolT ismalloc;           /* True if qhull should free points in qh_freeqhull() or reallocation */
71  char flags[]= "qhull Tv"; /* option flags for qhull, see qh_opt.htm */
72  FILE *outfile= stdout;    /* output from qh_produce_output()
73                               use NULL to skip qh_produce_output() */
74  FILE *errfile= stderr;    /* error messages from qhull code */
75  int exitcode;             /* 0 if no error from qhull */
76  facetT *facet;            /* set by FORALLfacets */
77  int curlong, totlong;     /* memory remaining after qh_memfreeshort */
78
79#if qh_QHpointer  /* see user.h */
80  if (qh_qh){
81      printf ("QH6238: Qhull link error.  The global variable qh_qh was not initialized\n\
82              to NULL by global.c.  Please compile this program with -Dqh_QHpointer_dllimport\n\
83              as well as -Dqh_QHpointer, or use libqhullstatic, or use a different tool chain.\n\n");
84      exit -1;
85  }
86#endif
87
88  /* initialize dim, numpoints, points[], ismalloc here */
89  exitcode= qh_new_qhull(dim, numpoints, points, ismalloc,
90                      flags, outfile, errfile);
91  if (!exitcode) {                  /* if no error */
92    /* 'qh facet_list' contains the convex hull */
93    FORALLfacets {
94       /* ... your code ... */
95    }
96  }
97  qh_freeqhull(!qh_ALL);
98  qh_memfreeshort(&curlong, &totlong);
99  if (curlong || totlong)
100    qh_fprintf(errfile, 7068, "qhull internal warning (main): did not free %d bytes of long memory(%d pieces)\n", totlong, curlong);
101}
102#endif
103
104/*-<a                             href="qh-user.htm#TOC"
105  >-------------------------------</a><a name="new_qhull">-</a>
106
107  qh_new_qhull( dim, numpoints, points, ismalloc, qhull_cmd, outfile, errfile )
108    build new qhull data structure and return exitcode (0 if no errors)
109
110  notes:
111    do not modify points until finished with results.
112      The qhull data structure contains pointers into the points array.
113    do not call qhull functions before qh_new_qhull().
114      The qhull data structure is not initialized until qh_new_qhull().
115
116    outfile may be null
117    qhull_cmd must start with "qhull "
118    projects points to a new point array for Delaunay triangulations ('d' and 'v')
119    transforms points into a new point array for halfspace intersection ('H')
120
121
122  To allow multiple, concurrent calls to qhull()
123    - set qh_QHpointer in user.h
124    - use qh_save_qhull and qh_restore_qhull to swap the global data structure between calls.
125    - use qh_freeqhull(qh_ALL) to free intermediate convex hulls
126
127  see:
128    user_eg.c for an example
129*/
130int qh_new_qhull(int dim, int numpoints, coordT *points, boolT ismalloc,
131                char *qhull_cmd, FILE *outfile, FILE *errfile) {
132  int exitcode, hulldim;
133  boolT new_ismalloc;
134  static boolT firstcall = True;
135  coordT *new_points;
136
137  if (firstcall) {
138    qh_meminit(errfile);
139    firstcall= False;
140  }
141  if (strncmp(qhull_cmd,"qhull ", (size_t)6)) {
142    qh_fprintf(errfile, 6186, "qhull error (qh_new_qhull): start qhull_cmd argument with \"qhull \"\n");
143    qh_exit(qh_ERRinput);
144  }
145  qh_initqhull_start(NULL, outfile, errfile);
146  trace1((qh ferr, 1044, "qh_new_qhull: build new Qhull for %d %d-d points with %s\n", numpoints, dim, qhull_cmd));
147  exitcode = setjmp(qh errexit);
148  if (!exitcode)
149  {
150    qh NOerrexit = False;
151    qh_initflags(qhull_cmd);
152    if (qh DELAUNAY)
153      qh PROJECTdelaunay= True;
154    if (qh HALFspace) {
155      /* points is an array of halfspaces,
156         the last coordinate of each halfspace is its offset */
157      hulldim= dim-1;
158      qh_setfeasible(hulldim);
159      new_points= qh_sethalfspace_all(dim, numpoints, points, qh feasible_point);
160      new_ismalloc= True;
161      if (ismalloc)
162        qh_free(points);
163    }else {
164      hulldim= dim;
165      new_points= points;
166      new_ismalloc= ismalloc;
167    }
168    qh_init_B(new_points, numpoints, hulldim, new_ismalloc);
169    qh_qhull();
170    qh_check_output();
171    if (outfile) {
172      qh_produce_output();
173    }else {
174      qh_prepare_output();
175    }
176    if (qh VERIFYoutput && !qh STOPpoint && !qh STOPcone)
177      qh_check_points();
178  }
179  qh NOerrexit = True;
180  return exitcode;
181} /* new_qhull */
182
183/*-<a                             href="qh-user.htm#TOC"
184  >-------------------------------</a><a name="errexit">-</a>
185
186  qh_errexit( exitcode, facet, ridge )
187    report and exit from an error
188    report facet and ridge if non-NULL
189    reports useful information such as last point processed
190    set qh.FORCEoutput to print neighborhood of facet
191
192  see:
193    qh_errexit2() in libqhull.c for printing 2 facets
194
195  design:
196    check for error within error processing
197    compute qh.hulltime
198    print facet and ridge (if any)
199    report commandString, options, qh.furthest_id
200    print summary and statistics (including precision statistics)
201    if qh_ERRsingular
202      print help text for singular data set
203    exit program via long jump (if defined) or exit()
204*/
205void qh_errexit(int exitcode, facetT *facet, ridgeT *ridge) {
206
207  if (qh ERREXITcalled) {
208    qh_fprintf(qh ferr, 8126, "\nqhull error while processing previous error.  Exit program\n");
209    qh_exit(qh_ERRqhull);
210  }
211  qh ERREXITcalled= True;
212  if (!qh QHULLfinished)
213    qh hulltime= qh_CPUclock - qh hulltime;
214  qh_errprint("ERRONEOUS", facet, NULL, ridge, NULL);
215  qh_fprintf(qh ferr, 8127, "\nWhile executing: %s | %s\n", qh rbox_command, qh qhull_command);
216  qh_fprintf(qh ferr, 8128, "Options selected for Qhull %s:\n%s\n", qh_version, qh qhull_options);
217  if (qh furthest_id >= 0) {
218    qh_fprintf(qh ferr, 8129, "Last point added to hull was p%d.", qh furthest_id);
219    if (zzval_(Ztotmerge))
220      qh_fprintf(qh ferr, 8130, "  Last merge was #%d.", zzval_(Ztotmerge));
221    if (qh QHULLfinished)
222      qh_fprintf(qh ferr, 8131, "\nQhull has finished constructing the hull.");
223    else if (qh POSTmerging)
224      qh_fprintf(qh ferr, 8132, "\nQhull has started post-merging.");
225    qh_fprintf(qh ferr, 8133, "\n");
226  }
227  if (qh FORCEoutput && (qh QHULLfinished || (!facet && !ridge)))
228    qh_produce_output();
229  else if (exitcode != qh_ERRinput) {
230    if (exitcode != qh_ERRsingular && zzval_(Zsetplane) > qh hull_dim+1) {
231      qh_fprintf(qh ferr, 8134, "\nAt error exit:\n");
232      qh_printsummary(qh ferr);
233      if (qh PRINTstatistics) {
234        qh_collectstatistics();
235        qh_printstatistics(qh ferr, "at error exit");
236        qh_memstatistics(qh ferr);
237      }
238    }
239    if (qh PRINTprecision)
240      qh_printstats(qh ferr, qhstat precision, NULL);
241  }
242  if (!exitcode)
243    exitcode= qh_ERRqhull;
244  else if (exitcode == qh_ERRsingular)
245    qh_printhelp_singular(qh ferr);
246  else if (exitcode == qh_ERRprec && !qh PREmerge)
247    qh_printhelp_degenerate(qh ferr);
248  if (qh NOerrexit) {
249    qh_fprintf(qh ferr, 6187, "qhull error while ending program.  Exit program\n");
250    qh_exit(qh_ERRqhull);
251  }
252  qh ERREXITcalled= False;
253  qh NOerrexit= True;
254  longjmp(qh errexit, exitcode);
255} /* errexit */
256
257
258/*-<a                             href="qh-user.htm#TOC"
259  >-------------------------------</a><a name="errprint">-</a>
260
261  qh_errprint( fp, string, atfacet, otherfacet, atridge, atvertex )
262    prints out the information of facets and ridges to fp
263    also prints neighbors and geomview output
264
265  notes:
266    except for string, any parameter may be NULL
267*/
268void qh_errprint(const char *string, facetT *atfacet, facetT *otherfacet, ridgeT *atridge, vertexT *atvertex) {
269  int i;
270
271  if (atfacet) {
272    qh_fprintf(qh ferr, 8135, "%s FACET:\n", string);
273    qh_printfacet(qh ferr, atfacet);
274  }
275  if (otherfacet) {
276    qh_fprintf(qh ferr, 8136, "%s OTHER FACET:\n", string);
277    qh_printfacet(qh ferr, otherfacet);
278  }
279  if (atridge) {
280    qh_fprintf(qh ferr, 8137, "%s RIDGE:\n", string);
281    qh_printridge(qh ferr, atridge);
282    if (atridge->top && atridge->top != atfacet && atridge->top != otherfacet)
283      qh_printfacet(qh ferr, atridge->top);
284    if (atridge->bottom
285        && atridge->bottom != atfacet && atridge->bottom != otherfacet)
286      qh_printfacet(qh ferr, atridge->bottom);
287    if (!atfacet)
288      atfacet= atridge->top;
289    if (!otherfacet)
290      otherfacet= otherfacet_(atridge, atfacet);
291  }
292  if (atvertex) {
293    qh_fprintf(qh ferr, 8138, "%s VERTEX:\n", string);
294    qh_printvertex(qh ferr, atvertex);
295  }
296  if (qh fout && qh FORCEoutput && atfacet && !qh QHULLfinished && !qh IStracing) {
297    qh_fprintf(qh ferr, 8139, "ERRONEOUS and NEIGHBORING FACETS to output\n");
298    for (i=0; i < qh_PRINTEND; i++)  /* use fout for geomview output */
299      qh_printneighborhood(qh fout, qh PRINTout[i], atfacet, otherfacet,
300                            !qh_ALL);
301  }
302} /* errprint */
303
304
305/*-<a                             href="qh-user.htm#TOC"
306  >-------------------------------</a><a name="printfacetlist">-</a>
307
308  qh_printfacetlist( fp, facetlist, facets, printall )
309    print all fields for a facet list and/or set of facets to fp
310    if !printall,
311      only prints good facets
312
313  notes:
314    also prints all vertices
315*/
316void qh_printfacetlist(facetT *facetlist, setT *facets, boolT printall) {
317  facetT *facet, **facetp;
318
319  qh_printbegin(qh ferr, qh_PRINTfacets, facetlist, facets, printall);
320  FORALLfacet_(facetlist)
321    qh_printafacet(qh ferr, qh_PRINTfacets, facet, printall);
322  FOREACHfacet_(facets)
323    qh_printafacet(qh ferr, qh_PRINTfacets, facet, printall);
324  qh_printend(qh ferr, qh_PRINTfacets, facetlist, facets, printall);
325} /* printfacetlist */
326
327
328/*-<a                             href="qh-io.htm#TOC"
329  >-------------------------------</a><a name="printhelp_degenerate">-</a>
330
331  qh_printhelp_degenerate( fp )
332    prints descriptive message for precision error
333
334  notes:
335    no message if qh_QUICKhelp
336*/
337void qh_printhelp_degenerate(FILE *fp) {
338
339  if (qh MERGEexact || qh PREmerge || qh JOGGLEmax < REALmax/2)
340    qh_fprintf(fp, 9368, "\n\
341A Qhull error has occurred.  Qhull should have corrected the above\n\
342precision error.  Please send the input and all of the output to\n\
343qhull_bug@qhull.org\n");
344  else if (!qh_QUICKhelp) {
345    qh_fprintf(fp, 9369, "\n\
346Precision problems were detected during construction of the convex hull.\n\
347This occurs because convex hull algorithms assume that calculations are\n\
348exact, but floating-point arithmetic has roundoff errors.\n\
349\n\
350To correct for precision problems, do not use 'Q0'.  By default, Qhull\n\
351selects 'C-0' or 'Qx' and merges non-convex facets.  With option 'QJ',\n\
352Qhull joggles the input to prevent precision problems.  See \"Imprecision\n\
353in Qhull\" (qh-impre.htm).\n\
354\n\
355If you use 'Q0', the output may include\n\
356coplanar ridges, concave ridges, and flipped facets.  In 4-d and higher,\n\
357Qhull may produce a ridge with four neighbors or two facets with the same \n\
358vertices.  Qhull reports these events when they occur.  It stops when a\n\
359concave ridge, flipped facet, or duplicate facet occurs.\n");
360#if REALfloat
361    qh_fprintf(fp, 9370, "\
362\n\
363Qhull is currently using single precision arithmetic.  The following\n\
364will probably remove the precision problems:\n\
365  - recompile qhull for realT precision(#define REALfloat 0 in user.h).\n");
366#endif
367    if (qh DELAUNAY && !qh SCALElast && qh MAXabs_coord > 1e4)
368      qh_fprintf(fp, 9371, "\
369\n\
370When computing the Delaunay triangulation of coordinates > 1.0,\n\
371  - use 'Qbb' to scale the last coordinate to [0,m] (max previous coordinate)\n");
372    if (qh DELAUNAY && !qh ATinfinity)
373      qh_fprintf(fp, 9372, "\
374When computing the Delaunay triangulation:\n\
375  - use 'Qz' to add a point at-infinity.  This reduces precision problems.\n");
376
377    qh_fprintf(fp, 9373, "\
378\n\
379If you need triangular output:\n\
380  - use option 'Qt' to triangulate the output\n\
381  - use option 'QJ' to joggle the input points and remove precision errors\n\
382  - use option 'Ft'.  It triangulates non-simplicial facets with added points.\n\
383\n\
384If you must use 'Q0',\n\
385try one or more of the following options.  They can not guarantee an output.\n\
386  - use 'QbB' to scale the input to a cube.\n\
387  - use 'Po' to produce output and prevent partitioning for flipped facets\n\
388  - use 'V0' to set min. distance to visible facet as 0 instead of roundoff\n\
389  - use 'En' to specify a maximum roundoff error less than %2.2g.\n\
390  - options 'Qf', 'Qbb', and 'QR0' may also help\n",
391               qh DISTround);
392    qh_fprintf(fp, 9374, "\
393\n\
394To guarantee simplicial output:\n\
395  - use option 'Qt' to triangulate the output\n\
396  - use option 'QJ' to joggle the input points and remove precision errors\n\
397  - use option 'Ft' to triangulate the output by adding points\n\
398  - use exact arithmetic (see \"Imprecision in Qhull\", qh-impre.htm)\n\
399");
400  }
401} /* printhelp_degenerate */
402
403
404/*-<a                             href="qh-globa.htm#TOC"
405  >-------------------------------</a><a name="printhelp_narrowhull">-</a>
406
407  qh_printhelp_narrowhull( minangle )
408    Warn about a narrow hull
409
410  notes:
411    Alternatively, reduce qh_WARNnarrow in user.h
412
413*/
414void qh_printhelp_narrowhull(FILE *fp, realT minangle) {
415
416    qh_fprintf(fp, 9375, "qhull precision warning: \n\
417The initial hull is narrow (cosine of min. angle is %.16f).\n\
418Is the input lower dimensional (e.g., on a plane in 3-d)?  Qhull may\n\
419produce a wide facet.  Options 'QbB' (scale to unit box) or 'Qbb' (scale\n\
420last coordinate) may remove this warning.  Use 'Pp' to skip this warning.\n\
421See 'Limitations' in qh-impre.htm.\n",
422          -minangle);   /* convert from angle between normals to angle between facets */
423} /* printhelp_narrowhull */
424
425/*-<a                             href="qh-io.htm#TOC"
426  >-------------------------------</a><a name="printhelp_singular">-</a>
427
428  qh_printhelp_singular( fp )
429    prints descriptive message for singular input
430*/
431void qh_printhelp_singular(FILE *fp) {
432  facetT *facet;
433  vertexT *vertex, **vertexp;
434  realT min, max, *coord, dist;
435  int i,k;
436
437  qh_fprintf(fp, 9376, "\n\
438The input to qhull appears to be less than %d dimensional, or a\n\
439computation has overflowed.\n\n\
440Qhull could not construct a clearly convex simplex from points:\n",
441           qh hull_dim);
442  qh_printvertexlist(fp, "", qh facet_list, NULL, qh_ALL);
443  if (!qh_QUICKhelp)
444    qh_fprintf(fp, 9377, "\n\
445The center point is coplanar with a facet, or a vertex is coplanar\n\
446with a neighboring facet.  The maximum round off error for\n\
447computing distances is %2.2g.  The center point, facets and distances\n\
448to the center point are as follows:\n\n", qh DISTround);
449  qh_printpointid(fp, "center point", qh hull_dim, qh interior_point, -1);
450  qh_fprintf(fp, 9378, "\n");
451  FORALLfacets {
452    qh_fprintf(fp, 9379, "facet");
453    FOREACHvertex_(facet->vertices)
454      qh_fprintf(fp, 9380, " p%d", qh_pointid(vertex->point));
455    zinc_(Zdistio);
456    qh_distplane(qh interior_point, facet, &dist);
457    qh_fprintf(fp, 9381, " distance= %4.2g\n", dist);
458  }
459  if (!qh_QUICKhelp) {
460    if (qh HALFspace)
461      qh_fprintf(fp, 9382, "\n\
462These points are the dual of the given halfspaces.  They indicate that\n\
463the intersection is degenerate.\n");
464    qh_fprintf(fp, 9383,"\n\
465These points either have a maximum or minimum x-coordinate, or\n\
466they maximize the determinant for k coordinates.  Trial points\n\
467are first selected from points that maximize a coordinate.\n");
468    if (qh hull_dim >= qh_INITIALmax)
469      qh_fprintf(fp, 9384, "\n\
470Because of the high dimension, the min x-coordinate and max-coordinate\n\
471points are used if the determinant is non-zero.  Option 'Qs' will\n\
472do a better, though much slower, job.  Instead of 'Qs', you can change\n\
473the points by randomly rotating the input with 'QR0'.\n");
474  }
475  qh_fprintf(fp, 9385, "\nThe min and max coordinates for each dimension are:\n");
476  for (k=0; k < qh hull_dim; k++) {
477    min= REALmax;
478    max= -REALmin;
479    for (i=qh num_points, coord= qh first_point+k; i--; coord += qh hull_dim) {
480      maximize_(max, *coord);
481      minimize_(min, *coord);
482    }
483    qh_fprintf(fp, 9386, "  %d:  %8.4g  %8.4g  difference= %4.4g\n", k, min, max, max-min);
484  }
485  if (!qh_QUICKhelp) {
486    qh_fprintf(fp, 9387, "\n\
487If the input should be full dimensional, you have several options that\n\
488may determine an initial simplex:\n\
489  - use 'QJ'  to joggle the input and make it full dimensional\n\
490  - use 'QbB' to scale the points to the unit cube\n\
491  - use 'QR0' to randomly rotate the input for different maximum points\n\
492  - use 'Qs'  to search all points for the initial simplex\n\
493  - use 'En'  to specify a maximum roundoff error less than %2.2g.\n\
494  - trace execution with 'T3' to see the determinant for each point.\n",
495                     qh DISTround);
496#if REALfloat
497    qh_fprintf(fp, 9388, "\
498  - recompile qhull for realT precision(#define REALfloat 0 in libqhull.h).\n");
499#endif
500    qh_fprintf(fp, 9389, "\n\
501If the input is lower dimensional:\n\
502  - use 'QJ' to joggle the input and make it full dimensional\n\
503  - use 'Qbk:0Bk:0' to delete coordinate k from the input.  You should\n\
504    pick the coordinate with the least range.  The hull will have the\n\
505    correct topology.\n\
506  - determine the flat containing the points, rotate the points\n\
507    into a coordinate plane, and delete the other coordinates.\n\
508  - add one or more points to make the input full dimensional.\n\
509");
510  }
511} /* printhelp_singular */
512
513/*-<a                             href="qh-globa.htm#TOC"
514  >-------------------------------</a><a name="user_memsizes">-</a>
515
516  qh_user_memsizes()
517    allocate up to 10 additional, quick allocation sizes
518
519  notes:
520    increase maximum number of allocations in qh_initqhull_mem()
521*/
522void qh_user_memsizes(void) {
523
524  /* qh_memsize(size); */
525} /* user_memsizes */
526
527
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