Actual source code: rgbasic.c

  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.
  7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
  8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  9: */
 10: /*
 11:    Basic RG routines
 12: */

 14: #include <slepc/private/rgimpl.h>

 16: PetscFunctionList RGList = NULL;
 17: PetscBool         RGRegisterAllCalled = PETSC_FALSE;
 18: PetscClassId      RG_CLASSID = 0;
 19: static PetscBool  RGPackageInitialized = PETSC_FALSE;

 21: /*@C
 22:    RGFinalizePackage - This function destroys everything in the SLEPc interface
 23:    to the `RG` package. It is called from `SlepcFinalize()`.

 25:    Level: developer

 27: .seealso: [](sec:rg), `SlepcFinalize()`, `BVInitializePackage()`
 28: @*/
 29: PetscErrorCode RGFinalizePackage(void)
 30: {
 31:   PetscFunctionBegin;
 32:   PetscCall(PetscFunctionListDestroy(&RGList));
 33:   RGPackageInitialized = PETSC_FALSE;
 34:   RGRegisterAllCalled  = PETSC_FALSE;
 35:   PetscFunctionReturn(PETSC_SUCCESS);
 36: }

 38: /*@C
 39:    RGInitializePackage - This function initializes everything in the `RG` package.
 40:    It is called from `PetscDLLibraryRegister_slepc()` when using dynamic libraries, and
 41:    on the first call to `RGCreate()` when using shared or static libraries.

 43:    Note:
 44:    This function never needs to be called by SLEPc users.

 46:    Level: developer

 48: .seealso: [](sec:rg), `RG`, `SlepcInitialize()`, `RGFinalizePackage()`
 49: @*/
 50: PetscErrorCode RGInitializePackage(void)
 51: {
 52:   char           logList[256];
 53:   PetscBool      opt,pkg;
 54:   PetscClassId   classids[1];

 56:   PetscFunctionBegin;
 57:   if (RGPackageInitialized) PetscFunctionReturn(PETSC_SUCCESS);
 58:   RGPackageInitialized = PETSC_TRUE;
 59:   /* Register Classes */
 60:   PetscCall(PetscClassIdRegister("Region",&RG_CLASSID));
 61:   /* Register Constructors */
 62:   PetscCall(RGRegisterAll());
 63:   /* Process Info */
 64:   classids[0] = RG_CLASSID;
 65:   PetscCall(PetscInfoProcessClass("rg",1,&classids[0]));
 66:   /* Process summary exclusions */
 67:   PetscCall(PetscOptionsGetString(NULL,NULL,"-log_exclude",logList,sizeof(logList),&opt));
 68:   if (opt) {
 69:     PetscCall(PetscStrInList("rg",logList,',',&pkg));
 70:     if (pkg) PetscCall(PetscLogEventDeactivateClass(RG_CLASSID));
 71:   }
 72:   /* Register package finalizer */
 73:   PetscCall(PetscRegisterFinalize(RGFinalizePackage));
 74:   PetscFunctionReturn(PETSC_SUCCESS);
 75: }

 77: /*@
 78:    RGCreate - Creates an `RG` context.

 80:    Collective

 82:    Input Parameter:
 83: .  comm - MPI communicator

 85:    Output Parameter:
 86: .  newrg - location to put the `RG` context

 88:    Level: beginner

 90: .seealso: [](sec:rg), `RG`, `RGDestroy()`
 91: @*/
 92: PetscErrorCode RGCreate(MPI_Comm comm,RG *newrg)
 93: {
 94:   RG             rg;

 96:   PetscFunctionBegin;
 97:   PetscAssertPointer(newrg,2);
 98:   PetscCall(RGInitializePackage());
 99:   PetscCall(SlepcHeaderCreate(rg,RG_CLASSID,"RG","Region","RG",comm,RGDestroy,RGView));
100:   rg->complement = PETSC_FALSE;
101:   rg->sfactor    = 1.0;
102:   rg->osfactor   = 0.0;
103:   rg->data       = NULL;

105:   *newrg = rg;
106:   PetscFunctionReturn(PETSC_SUCCESS);
107: }

109: /*@
110:    RGSetOptionsPrefix - Sets the prefix used for searching for all
111:    `RG` options in the database.

113:    Logically Collective

115:    Input Parameters:
116: +  rg     - the region context
117: -  prefix - the prefix string to prepend to all `RG` option requests

119:    Notes:
120:    A hyphen (-) must NOT be given at the beginning of the prefix name.
121:    The first character of all runtime options is AUTOMATICALLY the
122:    hyphen.

124:    Level: advanced

126: .seealso: [](sec:rg), `RGAppendOptionsPrefix()`
127: @*/
128: PetscErrorCode RGSetOptionsPrefix(RG rg,const char prefix[])
129: {
130:   PetscFunctionBegin;
132:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)rg,prefix));
133:   PetscFunctionReturn(PETSC_SUCCESS);
134: }

136: /*@
137:    RGAppendOptionsPrefix - Appends to the prefix used for searching for all
138:    `RG` options in the database.

140:    Logically Collective

142:    Input Parameters:
143: +  rg     - the region context
144: -  prefix - the prefix string to prepend to all `RG` option requests

146:    Notes:
147:    A hyphen (-) must NOT be given at the beginning of the prefix name.
148:    The first character of all runtime options is AUTOMATICALLY the hyphen.

150:    Level: advanced

152: .seealso: [](sec:rg), `RGSetOptionsPrefix()`
153: @*/
154: PetscErrorCode RGAppendOptionsPrefix(RG rg,const char prefix[])
155: {
156:   PetscFunctionBegin;
158:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)rg,prefix));
159:   PetscFunctionReturn(PETSC_SUCCESS);
160: }

162: /*@
163:    RGGetOptionsPrefix - Gets the prefix used for searching for all
164:    `RG` options in the database.

166:    Not Collective

168:    Input Parameter:
169: .  rg - the region context

171:    Output Parameter:
172: .  prefix - pointer to the prefix string used is returned

174:    Level: advanced

176: .seealso: [](sec:rg), `RGSetOptionsPrefix()`, `RGAppendOptionsPrefix()`
177: @*/
178: PetscErrorCode RGGetOptionsPrefix(RG rg,const char *prefix[])
179: {
180:   PetscFunctionBegin;
182:   PetscAssertPointer(prefix,2);
183:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)rg,prefix));
184:   PetscFunctionReturn(PETSC_SUCCESS);
185: }

187: /*@
188:    RGSetType - Selects the type for the `RG` object.

190:    Logically Collective

192:    Input Parameters:
193: +  rg   - the region context
194: -  type - a known type

196:    Options Database Key:
197: .  -rg_type <type> - Sets `RG` type

199:    Level: beginner

201: .seealso: [](sec:rg), `RGGetType()`
202: @*/
203: PetscErrorCode RGSetType(RG rg,RGType type)
204: {
205:   PetscErrorCode (*r)(RG);
206:   PetscBool      match;

208:   PetscFunctionBegin;
210:   PetscAssertPointer(type,2);

212:   PetscCall(PetscObjectTypeCompare((PetscObject)rg,type,&match));
213:   if (match) PetscFunctionReturn(PETSC_SUCCESS);

215:   PetscCall(PetscFunctionListFind(RGList,type,&r));
216:   PetscCheck(r,PetscObjectComm((PetscObject)rg),PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested RG type %s",type);

218:   PetscTryTypeMethod(rg,destroy);
219:   PetscCall(PetscMemzero(rg->ops,sizeof(struct _RGOps)));

221:   PetscCall(PetscObjectChangeTypeName((PetscObject)rg,type));
222:   PetscCall((*r)(rg));
223:   PetscFunctionReturn(PETSC_SUCCESS);
224: }

226: /*@
227:    RGGetType - Gets the `RG` type name (as a string) from the `RG` context.

229:    Not Collective

231:    Input Parameter:
232: .  rg - the region context

234:    Output Parameter:
235: .  type - name of the region

237:    Level: beginner

239: .seealso: [](sec:rg), `RGSetType()`
240: @*/
241: PetscErrorCode RGGetType(RG rg,RGType *type)
242: {
243:   PetscFunctionBegin;
245:   PetscAssertPointer(type,2);
246:   *type = ((PetscObject)rg)->type_name;
247:   PetscFunctionReturn(PETSC_SUCCESS);
248: }

250: /*@
251:    RGSetFromOptions - Sets `RG` options from the options database.

253:    Collective

255:    Input Parameter:
256: .  rg - the region context

258:    Note:
259:    To see all options, run your program with the `-help` option.

261:    Level: beginner

263: .seealso: [](sec:rg), `RGSetOptionsPrefix()`
264: @*/
265: PetscErrorCode RGSetFromOptions(RG rg)
266: {
267:   char           type[256];
268:   PetscBool      flg;
269:   PetscReal      sfactor;

271:   PetscFunctionBegin;
273:   PetscCall(RGRegisterAll());
274:   PetscObjectOptionsBegin((PetscObject)rg);
275:     PetscCall(PetscOptionsFList("-rg_type","Region type","RGSetType",RGList,(char*)(((PetscObject)rg)->type_name?((PetscObject)rg)->type_name:RGINTERVAL),type,sizeof(type),&flg));
276:     if (flg) PetscCall(RGSetType(rg,type));
277:     else if (!((PetscObject)rg)->type_name) PetscCall(RGSetType(rg,RGINTERVAL));

279:     PetscCall(PetscOptionsBool("-rg_complement","Whether region is complemented or not","RGSetComplement",rg->complement,&rg->complement,NULL));

281:     PetscCall(PetscOptionsReal("-rg_scale","Scaling factor","RGSetScale",1.0,&sfactor,&flg));
282:     if (flg) PetscCall(RGSetScale(rg,sfactor));

284:     PetscTryTypeMethod(rg,setfromoptions,PetscOptionsObject);
285:     PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)rg,PetscOptionsObject));
286:   PetscOptionsEnd();
287:   PetscFunctionReturn(PETSC_SUCCESS);
288: }

290: /*@
291:    RGView - Prints the `RG` data structure.

293:    Collective

295:    Input Parameters:
296: +  rg - the region context
297: -  viewer - optional visualization context

299:    Notes:
300:    The available visualization contexts include
301: +     `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
302: -     `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard output where only the
303:          first process opens the file; all other processes send their data to the
304:          first one to print

306:    The user can open an alternative visualization context with `PetscViewerASCIIOpen()`
307:    to output to a specified file.

309:    Use `RGViewFromOptions()` to allow the user to select many different `PetscViewerType`
310:    and formats from the options database.

312:    Level: beginner

314: .seealso: [](sec:rg), `RGCreate()`, `RGViewFromOptions()`
315: @*/
316: PetscErrorCode RGView(RG rg,PetscViewer viewer)
317: {
318:   PetscBool      isdraw,isascii;

320:   PetscFunctionBegin;
322:   if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)rg),&viewer));
324:   PetscCheckSameComm(rg,1,viewer,2);
325:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw));
326:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii));
327:   if (isascii) {
328:     PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)rg,viewer));
329:     PetscCall(PetscViewerASCIIPushTab(viewer));
330:     PetscTryTypeMethod(rg,view,viewer);
331:     PetscCall(PetscViewerASCIIPopTab(viewer));
332:     if (rg->complement) PetscCall(PetscViewerASCIIPrintf(viewer,"  selected region is the complement of the specified one\n"));
333:     if (rg->sfactor!=1.0) PetscCall(PetscViewerASCIIPrintf(viewer,"  scaling factor = %g\n",(double)rg->sfactor));
334:   } else if (isdraw) PetscTryTypeMethod(rg,view,viewer);
335:   PetscFunctionReturn(PETSC_SUCCESS);
336: }

338: /*@
339:    RGViewFromOptions - View (print) an `RG` object based on values in the options database.

341:    Collective

343:    Input Parameters:
344: +  rg   - the region context
345: .  obj  - optional object that provides the options prefix used to query the options database
346: -  name - command line option

348:    Level: intermediate

350: .seealso: [](sec:rg), `RGView()`, `RGCreate()`, `PetscObjectViewFromOptions()`
351: @*/
352: PetscErrorCode RGViewFromOptions(RG rg,PetscObject obj,const char name[])
353: {
354:   PetscFunctionBegin;
356:   PetscCall(PetscObjectViewFromOptions((PetscObject)rg,obj,name));
357:   PetscFunctionReturn(PETSC_SUCCESS);
358: }

360: /*@
361:    RGIsTrivial - Whether it is the trivial region (whole complex plane).

363:    Not Collective

365:    Input Parameter:
366: .  rg - the region context

368:    Output Parameter:
369: .  trivial - true if the region is equal to the whole complex plane, e.g.,
370:              an interval region with all four endpoints unbounded or an
371:              ellipse with infinite radius.

373:    Level: beginner

375: .seealso: [](sec:rg), `RGCheckInside()`
376: @*/
377: PetscErrorCode RGIsTrivial(RG rg,PetscBool *trivial)
378: {
379:   PetscFunctionBegin;
382:   PetscAssertPointer(trivial,2);
383:   *trivial = PETSC_FALSE;
384:   PetscTryTypeMethod(rg,istrivial,trivial);
385:   PetscFunctionReturn(PETSC_SUCCESS);
386: }

388: /*@
389:    RGCheckInside - Determines if a set of given points are inside the region or not.

391:    Not Collective

393:    Input Parameters:
394: +  rg - the region context
395: .  n  - number of points to check
396: .  ar - array of real parts
397: -  ai - array of imaginary parts

399:    Output Parameter:
400: .  inside - array of results (1=inside, 0=on the contour, -1=outside)

402:    Notes:
403:    The point `a` is expressed as a couple of `PetscScalar` variables `ar`, `ai`.
404:    If built with complex scalars, the point is supposed to be stored in `ar`,
405:    otherwise `ar`, `ai` contain the real and imaginary parts, respectively.

407:    If a scaling factor was set, the points are scaled before checking.

409:    Level: intermediate

411: .seealso: [](sec:rg), `RGSetScale()`, `RGSetComplement()`
412: @*/
413: PetscErrorCode RGCheckInside(RG rg,PetscInt n,PetscScalar ar[],PetscScalar ai[],PetscInt inside[])
414: {
415:   PetscReal      px,py;
416:   PetscInt       i;

418:   PetscFunctionBegin;
421:   PetscAssertPointer(ar,3);
422: #if !defined(PETSC_USE_COMPLEX)
423:   PetscAssertPointer(ai,4);
424: #endif
425:   PetscAssertPointer(inside,5);

427:   for (i=0;i<n;i++) {
428: #if defined(PETSC_USE_COMPLEX)
429:     px = PetscRealPart(ar[i]);
430:     py = PetscImaginaryPart(ar[i]);
431: #else
432:     px = ar[i];
433:     py = ai[i];
434: #endif
435:     if (PetscUnlikely(rg->sfactor != 1.0)) {
436:       px /= rg->sfactor;
437:       py /= rg->sfactor;
438:     }
439:     PetscUseTypeMethod(rg,checkinside,px,py,inside+i);
440:     if (PetscUnlikely(rg->complement)) inside[i] = -inside[i];
441:   }
442:   PetscFunctionReturn(PETSC_SUCCESS);
443: }

445: /*@
446:    RGIsAxisymmetric - Determines if the region is symmetric with respect
447:    to the real or imaginary axis.

449:    Not Collective

451:    Input Parameters:
452: +  rg       - the region context
453: -  vertical - `PETSC_TRUE` if symmetry must be checked against the vertical axis

455:    Output Parameter:
456: .  symm - `PETSC_TRUE` if the region is axisymmetric

458:    Note:
459:    If the vertical argument is true, symmetry is checked with respect to
460:    the vertical axis, otherwise with respect to the horizontal axis.

462:    Level: intermediate

464: .seealso: [](sec:rg), `RGCanUseConjugates()`
465: @*/
466: PetscErrorCode RGIsAxisymmetric(RG rg,PetscBool vertical,PetscBool *symm)
467: {
468:   PetscFunctionBegin;
471:   PetscAssertPointer(symm,3);
472:   *symm = PETSC_FALSE;
473:   PetscTryTypeMethod(rg,isaxisymmetric,vertical,symm);
474:   PetscFunctionReturn(PETSC_SUCCESS);
475: }

477: /*@
478:    RGCanUseConjugates - Used in contour integral methods to determine whether
479:    half of integration points can be avoided (use their conjugates).

481:    Not Collective

483:    Input Parameters:
484: +  rg       - the region context
485: -  realmats - `PETSC_TRUE` if the problem matrices are real

487:    Output Parameter:
488: .  useconj  - whether it is possible to use conjugates

490:    Notes:
491:    If some integration points are the conjugates of other points, then the
492:    associated computational cost can be saved. This depends on the problem
493:    matrices being real and also the region being symmetric with respect to
494:    the horizontal axis. The result is false if using real arithmetic or
495:    in the case of a flat region (height equal to zero).

497:    Level: developer

499: .seealso: [](sec:rg), `RGIsAxisymmetric()`
500: @*/
501: PetscErrorCode RGCanUseConjugates(RG rg,PetscBool realmats,PetscBool *useconj)
502: {
503: #if defined(PETSC_USE_COMPLEX)
504:   PetscReal      c,d;
505:   PetscBool      isaxisymm;
506: #endif

508:   PetscFunctionBegin;
511:   PetscAssertPointer(useconj,3);
512:   *useconj = PETSC_FALSE;
513: #if defined(PETSC_USE_COMPLEX)
514:   if (realmats) {
515:     PetscCall(RGIsAxisymmetric(rg,PETSC_FALSE,&isaxisymm));
516:     if (isaxisymm) {
517:       PetscCall(RGComputeBoundingBox(rg,NULL,NULL,&c,&d));
518:       if (c!=d) *useconj = PETSC_TRUE;
519:     }
520:   }
521: #endif
522:   PetscFunctionReturn(PETSC_SUCCESS);
523: }

525: /*@
526:    RGComputeContour - Computes the coordinates of several points lying on the
527:    contour of the region.

529:    Not Collective

531:    Input Parameters:
532: +  rg - the region context
533: -  n  - number of points to compute

535:    Output Parameters:
536: +  cr - location to store real parts
537: -  ci - location to store imaginary parts

539:    Note:
540:    In real scalars, either `cr` or `ci` can be `NULL` (but not both). In complex
541:    scalars, the coordinates are stored in `cr`, which cannot be `NULL` (`ci` is
542:    not referenced).

544:    Level: intermediate

546: .seealso: [](sec:rg), `RGComputeBoundingBox()`, `RGSetScale()`
547: @*/
548: PetscErrorCode RGComputeContour(RG rg,PetscInt n,PetscScalar cr[],PetscScalar ci[])
549: {
550:   PetscInt       i;

552:   PetscFunctionBegin;
555: #if defined(PETSC_USE_COMPLEX)
556:   PetscAssertPointer(cr,3);
557: #else
558:   PetscCheck(cr || ci,PetscObjectComm((PetscObject)rg),PETSC_ERR_SUP,"cr and ci cannot be NULL simultaneously");
559: #endif
560:   PetscCheck(!rg->complement,PetscObjectComm((PetscObject)rg),PETSC_ERR_SUP,"Cannot compute contour of region with complement flag set");
561:   PetscUseTypeMethod(rg,computecontour,n,cr,ci);
562:   for (i=0;i<n;i++) {
563:     if (cr) cr[i] *= rg->sfactor;
564:     if (ci) ci[i] *= rg->sfactor;
565:   }
566:   PetscFunctionReturn(PETSC_SUCCESS);
567: }

569: /*@
570:    RGComputeBoundingBox - Determines the endpoints of a rectangle in the complex plane that
571:    contains the region.

573:    Not Collective

575:    Input Parameter:
576: .  rg - the region context

578:    Output Parameters:
579: +  a - left endpoint of the bounding box in the real axis
580: .  b - right endpoint of the bounding box in the real axis
581: .  c - bottom endpoint of the bounding box in the imaginary axis
582: -  d - top endpoint of the bounding box in the imaginary axis

584:    Note:
585:    The bounding box is defined as $[a,b]\times[c,d]$. In regions that are not bounded (e.g., an
586:    open interval) or with the complement flag set, it makes no sense to compute a bounding
587:    box, so the return values are infinite.

589:    Level: intermediate

591: .seealso: [](sec:rg), `RGComputeContour()`, `RGSetScale()`, `RGSetComplement()`
592: @*/
593: PetscErrorCode RGComputeBoundingBox(RG rg,PetscReal *a,PetscReal *b,PetscReal *c,PetscReal *d)
594: {
595:   PetscFunctionBegin;

599:   if (rg->complement) {  /* cannot compute bounding box */
600:     if (a) *a = -PETSC_MAX_REAL;
601:     if (b) *b =  PETSC_MAX_REAL;
602:     if (c) *c = -PETSC_MAX_REAL;
603:     if (d) *d =  PETSC_MAX_REAL;
604:   } else {
605:     PetscUseTypeMethod(rg,computebbox,a,b,c,d);
606:     if (a && *a!=-PETSC_MAX_REAL) *a *= rg->sfactor;
607:     if (b && *b!= PETSC_MAX_REAL) *b *= rg->sfactor;
608:     if (c && *c!=-PETSC_MAX_REAL) *c *= rg->sfactor;
609:     if (d && *d!= PETSC_MAX_REAL) *d *= rg->sfactor;
610:   }
611:   PetscFunctionReturn(PETSC_SUCCESS);
612: }

614: /*@
615:    RGComputeQuadrature - Computes the values of the parameters used in a
616:    quadrature rule for a contour integral around the boundary of the region.

618:    Not Collective

620:    Input Parameters:
621: +  rg   - the region context
622: .  quad - the type of quadrature
623: -  n    - number of quadrature points to compute

625:    Output Parameters:
626: +  z  - quadrature points
627: .  zn - normalized quadrature points
628: -  w  - quadrature weights

630:    Notes:
631:    In complex scalars, the values returned in `z` are often the same as those
632:    computed by `RGComputeContour()`, but this is not the case in real scalars
633:    where all output arguments are real.

635:    The computed values change for different quadrature rules.

637:    Level: advanced

639: .seealso: [](sec:rg), `RGComputeContour()`
640: @*/
641: PetscErrorCode RGComputeQuadrature(RG rg,RGQuadRule quad,PetscInt n,PetscScalar z[],PetscScalar zn[],PetscScalar w[])
642: {
643:   PetscFunctionBegin;
646:   PetscAssertPointer(z,4);
647:   PetscAssertPointer(zn,5);
648:   PetscAssertPointer(w,6);

650:   PetscCall(RGComputeContour(rg,n,z,NULL));
651:   PetscUseTypeMethod(rg,computequadrature,quad,n,z,zn,w);
652:   PetscFunctionReturn(PETSC_SUCCESS);
653: }

655: /*@
656:    RGSetComplement - Sets a flag to indicate that the region is the complement
657:    of the specified one.

659:    Logically Collective

661:    Input Parameters:
662: +  rg  - the region context
663: -  flg - the boolean flag

665:    Options Database Key:
666: .  -rg_complement <bool> - Activate/deactivate complementing of the region

668:    Level: intermediate

670: .seealso: [](sec:rg), `RGGetComplement()`
671: @*/
672: PetscErrorCode RGSetComplement(RG rg,PetscBool flg)
673: {
674:   PetscFunctionBegin;
677:   rg->complement = flg;
678:   PetscFunctionReturn(PETSC_SUCCESS);
679: }

681: /*@
682:    RGGetComplement - Gets a flag that indicates whether the region
683:    is complemented or not.

685:    Not Collective

687:    Input Parameter:
688: .  rg - the region context

690:    Output Parameter:
691: .  flg - the flag

693:    Level: intermediate

695: .seealso: [](sec:rg), `RGSetComplement()`
696: @*/
697: PetscErrorCode RGGetComplement(RG rg,PetscBool *flg)
698: {
699:   PetscFunctionBegin;
701:   PetscAssertPointer(flg,2);
702:   *flg = rg->complement;
703:   PetscFunctionReturn(PETSC_SUCCESS);
704: }

706: /*@
707:    RGSetScale - Sets the scaling factor to be used when checking that a
708:    point is inside the region and when computing the contour.

710:    Logically Collective

712:    Input Parameters:
713: +  rg      - the region context
714: -  sfactor - the scaling factor

716:    Options Database Key:
717: .  -rg_scale <real> - Sets the scaling factor

719:    Level: intermediate

721: .seealso: [](sec:rg), `RGGetScale()`, `RGCheckInside()`, `RGComputeContour()`
722: @*/
723: PetscErrorCode RGSetScale(RG rg,PetscReal sfactor)
724: {
725:   PetscFunctionBegin;
728:   if (sfactor == (PetscReal)PETSC_DEFAULT || sfactor == (PetscReal)PETSC_DECIDE) sfactor = 1.0;
729:   PetscCheck(sfactor>0.0,PetscObjectComm((PetscObject)rg),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of scaling factor. Must be > 0");
730:   rg->sfactor = sfactor;
731:   PetscFunctionReturn(PETSC_SUCCESS);
732: }

734: /*@
735:    RGGetScale - Gets the scaling factor.

737:    Not Collective

739:    Input Parameter:
740: .  rg - the region context

742:    Output Parameter:
743: .  sfactor - the scaling factor

745:    Level: intermediate

747: .seealso: [](sec:rg), `RGSetScale()`
748: @*/
749: PetscErrorCode RGGetScale(RG rg,PetscReal *sfactor)
750: {
751:   PetscFunctionBegin;
753:   PetscAssertPointer(sfactor,2);
754:   *sfactor = rg->sfactor;
755:   PetscFunctionReturn(PETSC_SUCCESS);
756: }

758: /*@
759:    RGPushScale - Sets an additional scaling factor, that will multiply the
760:    user-defined scaling factor.

762:    Logically Collective

764:    Input Parameters:
765: +  rg      - the region context
766: -  sfactor - the scaling factor

768:    Notes:
769:    The current implementation does not allow pushing several scaling factors.

771:    This is intended for internal use, for instance in polynomial eigensolvers
772:    that use parameter scaling.

774:    Level: developer

776: .seealso: [](sec:rg), `RGPopScale()`, `RGSetScale()`
777: @*/
778: PetscErrorCode RGPushScale(RG rg,PetscReal sfactor)
779: {
780:   PetscFunctionBegin;
783:   PetscCheck(sfactor>0.0,PetscObjectComm((PetscObject)rg),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of scaling factor. Must be > 0");
784:   PetscCheck(!rg->osfactor,PetscObjectComm((PetscObject)rg),PETSC_ERR_SUP,"Current implementation does not allow pushing several scaling factors");
785:   rg->osfactor = rg->sfactor;
786:   rg->sfactor *= sfactor;
787:   PetscFunctionReturn(PETSC_SUCCESS);
788: }

790: /*@
791:    RGPopScale - Pops the scaling factor set with `RGPushScale()`.

793:    Logically Collective

795:    Input Parameter:
796: .  rg - the region context

798:    Level: developer

800: .seealso: [](sec:rg), `RGPushScale()`
801: @*/
802: PetscErrorCode RGPopScale(RG rg)
803: {
804:   PetscFunctionBegin;
806:   PetscCheck(rg->osfactor,PetscObjectComm((PetscObject)rg),PETSC_ERR_ORDER,"Must call RGPushScale first");
807:   rg->sfactor  = rg->osfactor;
808:   rg->osfactor = 0.0;
809:   PetscFunctionReturn(PETSC_SUCCESS);
810: }

812: /*@
813:    RGDestroy - Destroys `RG` context that was created with `RGCreate()`.

815:    Collective

817:    Input Parameter:
818: .  rg - the region context

820:    Level: beginner

822: .seealso: [](sec:rg), `RGCreate()`
823: @*/
824: PetscErrorCode RGDestroy(RG *rg)
825: {
826:   PetscFunctionBegin;
827:   if (!*rg) PetscFunctionReturn(PETSC_SUCCESS);
829:   if (--((PetscObject)*rg)->refct > 0) { *rg = NULL; PetscFunctionReturn(PETSC_SUCCESS); }
830:   PetscTryTypeMethod(*rg,destroy);
831:   PetscCall(PetscHeaderDestroy(rg));
832:   PetscFunctionReturn(PETSC_SUCCESS);
833: }

835: /*@C
836:    RGRegister - Adds a region to the `RG` package.

838:    Not Collective

840:    Input Parameters:
841: +  name - name of a new user-defined RG
842: -  function - routine to create context

844:    Note:
845:    `RGRegister()` may be called multiple times to add several user-defined regions.

847:    Level: advanced

849: .seealso: [](sec:rg), `RGRegisterAll()`
850: @*/
851: PetscErrorCode RGRegister(const char *name,PetscErrorCode (*function)(RG))
852: {
853:   PetscFunctionBegin;
854:   PetscCall(RGInitializePackage());
855:   PetscCall(PetscFunctionListAdd(&RGList,name,function));
856:   PetscFunctionReturn(PETSC_SUCCESS);
857: }