Actual source code: shell.c

petsc-3.10.3 2018-12-18
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  2: /*
  3:    This provides a simple shell for Fortran (and C programmers) to
  4:   create a very simple matrix class for use with KSP without coding
  5:   much of anything.
  6: */

  8:  #include <petsc/private/matimpl.h>

 10: struct _MatShellOps {
 11:   /*  3 */ PetscErrorCode (*mult)(Mat,Vec,Vec);
 12:   /*  5 */ PetscErrorCode (*multtranspose)(Mat,Vec,Vec);
 13:   /* 17 */ PetscErrorCode (*getdiagonal)(Mat,Vec);
 14:   /* 43 */ PetscErrorCode (*copy)(Mat,Mat,MatStructure);
 15:   /* 60 */ PetscErrorCode (*destroy)(Mat);
 16: };

 18: typedef struct {
 19:   struct _MatShellOps ops[1];

 21:   PetscScalar vscale,vshift;
 22:   Vec         dshift;
 23:   Vec         left,right;
 24:   Vec         left_work,right_work;
 25:   Vec         left_add_work,right_add_work;
 26:   Mat         axpy;
 27:   PetscScalar axpy_vscale;
 28:   PetscBool   managescalingshifts;                   /* The user will manage the scaling and shifts for the MATSHELL, not the default */
 29:   void        *ctx;
 30: } Mat_Shell;

 32: /*
 33:       xx = diag(left)*x
 34: */
 35: static PetscErrorCode MatShellPreScaleLeft(Mat A,Vec x,Vec *xx)
 36: {
 37:   Mat_Shell      *shell = (Mat_Shell*)A->data;

 41:   *xx = NULL;
 42:   if (!shell->left) {
 43:     *xx = x;
 44:   } else {
 45:     if (!shell->left_work) {VecDuplicate(shell->left,&shell->left_work);}
 46:     VecPointwiseMult(shell->left_work,x,shell->left);
 47:     *xx  = shell->left_work;
 48:   }
 49:   return(0);
 50: }

 52: /*
 53:      xx = diag(right)*x
 54: */
 55: static PetscErrorCode MatShellPreScaleRight(Mat A,Vec x,Vec *xx)
 56: {
 57:   Mat_Shell      *shell = (Mat_Shell*)A->data;

 61:   *xx = NULL;
 62:   if (!shell->right) {
 63:     *xx = x;
 64:   } else {
 65:     if (!shell->right_work) {VecDuplicate(shell->right,&shell->right_work);}
 66:     VecPointwiseMult(shell->right_work,x,shell->right);
 67:     *xx  = shell->right_work;
 68:   }
 69:   return(0);
 70: }

 72: /*
 73:     x = diag(left)*x
 74: */
 75: static PetscErrorCode MatShellPostScaleLeft(Mat A,Vec x)
 76: {
 77:   Mat_Shell      *shell = (Mat_Shell*)A->data;

 81:   if (shell->left) {VecPointwiseMult(x,x,shell->left);}
 82:   return(0);
 83: }

 85: /*
 86:     x = diag(right)*x
 87: */
 88: static PetscErrorCode MatShellPostScaleRight(Mat A,Vec x)
 89: {
 90:   Mat_Shell      *shell = (Mat_Shell*)A->data;

 94:   if (shell->right) {VecPointwiseMult(x,x,shell->right);}
 95:   return(0);
 96: }

 98: /*
 99:          Y = vscale*Y + diag(dshift)*X + vshift*X

101:          On input Y already contains A*x
102: */
103: static PetscErrorCode MatShellShiftAndScale(Mat A,Vec X,Vec Y)
104: {
105:   Mat_Shell      *shell = (Mat_Shell*)A->data;

109:   if (shell->dshift) {          /* get arrays because there is no VecPointwiseMultAdd() */
110:     PetscInt          i,m;
111:     const PetscScalar *x,*d;
112:     PetscScalar       *y;
113:     VecGetLocalSize(X,&m);
114:     VecGetArrayRead(shell->dshift,&d);
115:     VecGetArrayRead(X,&x);
116:     VecGetArray(Y,&y);
117:     for (i=0; i<m; i++) y[i] = shell->vscale*y[i] + d[i]*x[i];
118:     VecRestoreArrayRead(shell->dshift,&d);
119:     VecRestoreArrayRead(X,&x);
120:     VecRestoreArray(Y,&y);
121:   } else {
122:     VecScale(Y,shell->vscale);
123:   }
124:   if (shell->vshift != 0.0) {VecAXPY(Y,shell->vshift,X);} /* if test is for non-square matrices */
125:   return(0);
126: }

128: /*@
129:     MatShellGetContext - Returns the user-provided context associated with a shell matrix.

131:     Not Collective

133:     Input Parameter:
134: .   mat - the matrix, should have been created with MatCreateShell()

136:     Output Parameter:
137: .   ctx - the user provided context

139:     Level: advanced

141:    Fortran Notes:
142:     To use this from Fortran you must write a Fortran interface definition for this
143:     function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.

145: .keywords: matrix, shell, get, context

147: .seealso: MatCreateShell(), MatShellSetOperation(), MatShellSetContext()
148: @*/
149: PetscErrorCode  MatShellGetContext(Mat mat,void *ctx)
150: {
152:   PetscBool      flg;

157:   PetscObjectTypeCompare((PetscObject)mat,MATSHELL,&flg);
158:   if (flg) *(void**)ctx = ((Mat_Shell*)(mat->data))->ctx;
159:   else SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot get context from non-shell matrix");
160:   return(0);
161: }

163: PetscErrorCode MatDestroy_Shell(Mat mat)
164: {
166:   Mat_Shell      *shell = (Mat_Shell*)mat->data;

169:   if (shell->ops->destroy) {
170:     (*shell->ops->destroy)(mat);
171:   }
172:   VecDestroy(&shell->left);
173:   VecDestroy(&shell->right);
174:   VecDestroy(&shell->dshift);
175:   VecDestroy(&shell->left_work);
176:   VecDestroy(&shell->right_work);
177:   VecDestroy(&shell->left_add_work);
178:   VecDestroy(&shell->right_add_work);
179:   MatDestroy(&shell->axpy);
180:   PetscFree(mat->data);
181:   return(0);
182: }

184: PetscErrorCode MatCopy_Shell(Mat A,Mat B,MatStructure str)
185: {
186:   Mat_Shell       *shellA = (Mat_Shell*)A->data,*shellB = (Mat_Shell*)B->data;
187:   PetscErrorCode  ierr;
188:   PetscBool       matflg;

191:   PetscObjectTypeCompare((PetscObject)B,MATSHELL,&matflg);
192:   if (!matflg) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_NOTSAMETYPE,"Output matrix must be a MATSHELL");

194:   PetscMemcpy(B->ops,A->ops,sizeof(struct _MatOps));
195:   PetscMemcpy(shellB->ops,shellA->ops,sizeof(struct _MatShellOps));

197:   if (shellA->ops->copy) {
198:     (*shellA->ops->copy)(A,B,str);
199:   }
200:   shellB->vscale = shellA->vscale;
201:   shellB->vshift = shellA->vshift;
202:   if (shellA->dshift) {
203:     if (!shellB->dshift) {
204:       VecDuplicate(shellA->dshift,&shellB->dshift);
205:     }
206:     VecCopy(shellA->dshift,shellB->dshift);
207:   } else {
208:     VecDestroy(&shellB->dshift);
209:   }
210:   if (shellA->left) {
211:     if (!shellB->left) {
212:       VecDuplicate(shellA->left,&shellB->left);
213:     }
214:     VecCopy(shellA->left,shellB->left);
215:   } else {
216:     VecDestroy(&shellB->left);
217:   }
218:   if (shellA->right) {
219:     if (!shellB->right) {
220:       VecDuplicate(shellA->right,&shellB->right);
221:     }
222:     VecCopy(shellA->right,shellB->right);
223:   } else {
224:     VecDestroy(&shellB->right);
225:   }
226:   MatDestroy(&shellB->axpy);
227:   if (shellA->axpy) {
228:     PetscObjectReference((PetscObject)shellA->axpy);
229:     shellB->axpy        = shellA->axpy;
230:     shellB->axpy_vscale = shellA->axpy_vscale;
231:   }
232:   return(0);
233: }

235: PetscErrorCode MatDuplicate_Shell(Mat mat,MatDuplicateOption op,Mat *M)
236: {
238:   void           *ctx;

241:   MatShellGetContext(mat,&ctx);
242:   MatCreateShell(PetscObjectComm((PetscObject)mat),mat->rmap->n,mat->cmap->n,mat->rmap->N,mat->cmap->N,ctx,M);
243:   MatCopy(mat,*M,SAME_NONZERO_PATTERN);
244:   return(0);
245: }

247: PetscErrorCode MatMult_Shell(Mat A,Vec x,Vec y)
248: {
249:   Mat_Shell        *shell = (Mat_Shell*)A->data;
250:   PetscErrorCode   ierr;
251:   Vec              xx;
252:   PetscObjectState instate,outstate;

255:   MatShellPreScaleRight(A,x,&xx);
256:   PetscObjectStateGet((PetscObject)y, &instate);
257:   if (!shell->ops->mult) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Have not provided a MatMult() for this MATSHELL");
258:   (*shell->ops->mult)(A,xx,y);
259:   PetscObjectStateGet((PetscObject)y, &outstate);
260:   if (instate == outstate) {
261:     /* increase the state of the output vector since the user did not update its state themself as should have been done */
262:     PetscObjectStateIncrease((PetscObject)y);
263:   }
264:   MatShellShiftAndScale(A,xx,y);
265:   MatShellPostScaleLeft(A,y);

267:   if (shell->axpy) {
268:     if (!shell->left_work) {MatCreateVecs(A,&shell->left_work,NULL);}
269:     MatMult(shell->axpy,x,shell->left_work);
270:     VecAXPY(y,shell->axpy_vscale,shell->left_work);
271:   }
272:   return(0);
273: }

275: PetscErrorCode MatMultAdd_Shell(Mat A,Vec x,Vec y,Vec z)
276: {
277:   Mat_Shell      *shell = (Mat_Shell*)A->data;

281:   if (y == z) {
282:     if (!shell->right_add_work) {VecDuplicate(z,&shell->right_add_work);}
283:     MatMult(A,x,shell->right_add_work);
284:     VecAXPY(z,1.0,shell->right_add_work);
285:   } else {
286:     MatMult(A,x,z);
287:     VecAXPY(z,1.0,y);
288:   }
289:   return(0);
290: }

292: PetscErrorCode MatMultTranspose_Shell(Mat A,Vec x,Vec y)
293: {
294:   Mat_Shell        *shell = (Mat_Shell*)A->data;
295:   PetscErrorCode   ierr;
296:   Vec              xx;
297:   PetscObjectState instate,outstate;

300:   MatShellPreScaleLeft(A,x,&xx);
301:   PetscObjectStateGet((PetscObject)y, &instate);
302:   if (!shell->ops->multtranspose) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Have not provided a MatMultTranspose() for this MATSHELL");
303:   (*shell->ops->multtranspose)(A,xx,y);
304:   PetscObjectStateGet((PetscObject)y, &outstate);
305:   if (instate == outstate) {
306:     /* increase the state of the output vector since the user did not update its state themself as should have been done */
307:     PetscObjectStateIncrease((PetscObject)y);
308:   }
309:   MatShellShiftAndScale(A,xx,y);
310:   MatShellPostScaleRight(A,y);
311:   return(0);
312: }

314: PetscErrorCode MatMultTransposeAdd_Shell(Mat A,Vec x,Vec y,Vec z)
315: {
316:   Mat_Shell      *shell = (Mat_Shell*)A->data;

320:   if (y == z) {
321:     if (!shell->left_add_work) {VecDuplicate(z,&shell->left_add_work);}
322:     MatMultTranspose(A,x,shell->left_add_work);
323:     VecAXPY(z,1.0,shell->left_add_work);
324:   } else {
325:     MatMultTranspose(A,x,z);
326:     VecAXPY(z,1.0,y);
327:   }
328:   return(0);
329: }

331: /*
332:           diag(left)(vscale*A + diag(dshift) + vshift I)diag(right)
333: */
334: PetscErrorCode MatGetDiagonal_Shell(Mat A,Vec v)
335: {
336:   Mat_Shell      *shell = (Mat_Shell*)A->data;

340:   if (shell->ops->getdiagonal) {
341:     (*shell->ops->getdiagonal)(A,v);
342:   } else SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Must provide shell matrix with routine to return diagonal using\nMatShellSetOperation(S,MATOP_GET_DIAGONAL,...)");
343:   VecScale(v,shell->vscale);
344:   if (shell->dshift) {
345:     VecAXPY(v,1.0,shell->dshift);
346:   }
347:   VecShift(v,shell->vshift);
348:   if (shell->left)  {VecPointwiseMult(v,v,shell->left);}
349:   if (shell->right) {VecPointwiseMult(v,v,shell->right);}
350:   if (shell->axpy) {
351:     if (!shell->left_work) {VecDuplicate(v,&shell->left_work);}
352:     MatGetDiagonal(shell->axpy,shell->left_work);
353:     VecAXPY(v,shell->axpy_vscale,shell->left_work);
354:   }
355:   return(0);
356: }

358: PetscErrorCode MatShift_Shell(Mat Y,PetscScalar a)
359: {
360:   Mat_Shell      *shell = (Mat_Shell*)Y->data;

364:   if (shell->left || shell->right) {
365:     if (!shell->dshift) {
366:       VecDuplicate(shell->left ? shell->left : shell->right, &shell->dshift);
367:       VecSet(shell->dshift,a);
368:     } else {
369:       if (shell->left)  {VecPointwiseMult(shell->dshift,shell->dshift,shell->left);}
370:       if (shell->right) {VecPointwiseMult(shell->dshift,shell->dshift,shell->right);}
371:       VecShift(shell->dshift,a);
372:     }
373:     if (shell->left)  {VecPointwiseDivide(shell->dshift,shell->dshift,shell->left);}
374:     if (shell->right) {VecPointwiseDivide(shell->dshift,shell->dshift,shell->right);}
375:   } else shell->vshift += a;
376:   return(0);
377: }

379: PetscErrorCode MatDiagonalSet_Shell(Mat A,Vec D,InsertMode ins)
380: {
381:   Mat_Shell      *shell = (Mat_Shell*)A->data;

385:   if (ins == INSERT_VALUES) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE, "Operation not supported with INSERT_VALUES");
386:   if (!shell->dshift) {VecDuplicate(D,&shell->dshift);}
387:   if (shell->left || shell->right) {
388:     if (!shell->right_work) {VecDuplicate(shell->left ? shell->left : shell->right, &shell->right_work);}
389:     if (shell->left && shell->right)  {
390:       VecPointwiseDivide(shell->right_work,D,shell->left);
391:       VecPointwiseDivide(shell->right_work,shell->right_work,shell->right);
392:     } else if (shell->left) {
393:       VecPointwiseDivide(shell->right_work,D,shell->left);
394:     } else {
395:       VecPointwiseDivide(shell->right_work,D,shell->right);
396:     }
397:     if (!shell->dshift) {
398:       VecDuplicate(shell->left ? shell->left : shell->right, &shell->dshift);
399:       VecCopy(shell->dshift,shell->right_work);
400:     } else {
401:       VecAXPY(shell->dshift,1.0,shell->right_work);
402:     }
403:   } else {
404:     VecAXPY(shell->dshift,1.0,D);
405:   }
406:   return(0);
407: }

409: PetscErrorCode MatScale_Shell(Mat Y,PetscScalar a)
410: {
411:   Mat_Shell      *shell = (Mat_Shell*)Y->data;

415:   shell->vscale *= a;
416:   shell->vshift *= a;
417:   if (shell->dshift) {
418:     VecScale(shell->dshift,a);
419:   }
420:   shell->axpy_vscale *= a;
421:   return(0);
422: }

424: static PetscErrorCode MatDiagonalScale_Shell(Mat Y,Vec left,Vec right)
425: {
426:   Mat_Shell      *shell = (Mat_Shell*)Y->data;

430:   if (shell->axpy) SETERRQ(PetscObjectComm((PetscObject)Y),PETSC_ERR_SUP,"Cannot diagonal scale MATSHELL after MatAXPY operation");
431:   if (left) {
432:     if (!shell->left) {
433:       VecDuplicate(left,&shell->left);
434:       VecCopy(left,shell->left);
435:     } else {
436:       VecPointwiseMult(shell->left,shell->left,left);
437:     }
438:   }
439:   if (right) {
440:     if (!shell->right) {
441:       VecDuplicate(right,&shell->right);
442:       VecCopy(right,shell->right);
443:     } else {
444:       VecPointwiseMult(shell->right,shell->right,right);
445:     }
446:   }
447:   return(0);
448: }

450: PetscErrorCode MatAssemblyEnd_Shell(Mat Y,MatAssemblyType t)
451: {
452:   Mat_Shell      *shell = (Mat_Shell*)Y->data;

456:   if (t == MAT_FINAL_ASSEMBLY) {
457:     shell->vshift = 0.0;
458:     shell->vscale = 1.0;
459:     VecDestroy(&shell->dshift);
460:     VecDestroy(&shell->left);
461:     VecDestroy(&shell->right);
462:     MatDestroy(&shell->axpy);
463:   }
464:   return(0);
465: }

467: PETSC_INTERN PetscErrorCode MatConvert_Shell(Mat, MatType,MatReuse,Mat*);

469: static PetscErrorCode MatMissingDiagonal_Shell(Mat A,PetscBool  *missing,PetscInt *d)
470: {
472:   *missing = PETSC_FALSE;
473:   return(0);
474: }

476: PetscErrorCode MatAXPY_Shell(Mat Y,PetscScalar a,Mat X,MatStructure str)
477: {
478:   Mat_Shell      *shell = (Mat_Shell*)Y->data;

482:   PetscObjectReference((PetscObject)X);
483:   MatDestroy(&shell->axpy);
484:   shell->axpy        = X;
485:   shell->axpy_vscale = a;
486:   return(0);
487: }

489: static struct _MatOps MatOps_Values = {0,
490:                                        0,
491:                                        0,
492:                                        0,
493:                                 /* 4*/ MatMultAdd_Shell,
494:                                        0,
495:                                        MatMultTransposeAdd_Shell,
496:                                        0,
497:                                        0,
498:                                        0,
499:                                 /*10*/ 0,
500:                                        0,
501:                                        0,
502:                                        0,
503:                                        0,
504:                                 /*15*/ 0,
505:                                        0,
506:                                        0,
507:                                        MatDiagonalScale_Shell,
508:                                        0,
509:                                 /*20*/ 0,
510:                                        MatAssemblyEnd_Shell,
511:                                        0,
512:                                        0,
513:                                 /*24*/ 0,
514:                                        0,
515:                                        0,
516:                                        0,
517:                                        0,
518:                                 /*29*/ 0,
519:                                        0,
520:                                        0,
521:                                        0,
522:                                        0,
523:                                 /*34*/ MatDuplicate_Shell,
524:                                        0,
525:                                        0,
526:                                        0,
527:                                        0,
528:                                 /*39*/ MatAXPY_Shell,
529:                                        0,
530:                                        0,
531:                                        0,
532:                                        MatCopy_Shell,
533:                                 /*44*/ 0,
534:                                        MatScale_Shell,
535:                                        MatShift_Shell,
536:                                        MatDiagonalSet_Shell,
537:                                        0,
538:                                 /*49*/ 0,
539:                                        0,
540:                                        0,
541:                                        0,
542:                                        0,
543:                                 /*54*/ 0,
544:                                        0,
545:                                        0,
546:                                        0,
547:                                        0,
548:                                 /*59*/ 0,
549:                                        MatDestroy_Shell,
550:                                        0,
551:                                        0,
552:                                        0,
553:                                 /*64*/ 0,
554:                                        0,
555:                                        0,
556:                                        0,
557:                                        0,
558:                                 /*69*/ 0,
559:                                        0,
560:                                        MatConvert_Shell,
561:                                        0,
562:                                        0,
563:                                 /*74*/ 0,
564:                                        0,
565:                                        0,
566:                                        0,
567:                                        0,
568:                                 /*79*/ 0,
569:                                        0,
570:                                        0,
571:                                        0,
572:                                        0,
573:                                 /*84*/ 0,
574:                                        0,
575:                                        0,
576:                                        0,
577:                                        0,
578:                                 /*89*/ 0,
579:                                        0,
580:                                        0,
581:                                        0,
582:                                        0,
583:                                 /*94*/ 0,
584:                                        0,
585:                                        0,
586:                                        0,
587:                                        0,
588:                                 /*99*/ 0,
589:                                        0,
590:                                        0,
591:                                        0,
592:                                        0,
593:                                /*104*/ 0,
594:                                        0,
595:                                        0,
596:                                        0,
597:                                        0,
598:                                /*109*/ 0,
599:                                        0,
600:                                        0,
601:                                        0,
602:                                        MatMissingDiagonal_Shell,
603:                                /*114*/ 0,
604:                                        0,
605:                                        0,
606:                                        0,
607:                                        0,
608:                                /*119*/ 0,
609:                                        0,
610:                                        0,
611:                                        0,
612:                                        0,
613:                                /*124*/ 0,
614:                                        0,
615:                                        0,
616:                                        0,
617:                                        0,
618:                                /*129*/ 0,
619:                                        0,
620:                                        0,
621:                                        0,
622:                                        0,
623:                                /*134*/ 0,
624:                                        0,
625:                                        0,
626:                                        0,
627:                                        0,
628:                                /*139*/ 0,
629:                                        0,
630:                                        0
631: };

633: /*MC
634:    MATSHELL - MATSHELL = "shell" - A matrix type to be used to define your own matrix type -- perhaps matrix free.

636:   Level: advanced

638: .seealso: MatCreateShell()
639: M*/

641: PETSC_EXTERN PetscErrorCode MatCreate_Shell(Mat A)
642: {
643:   Mat_Shell      *b;

647:   PetscMemcpy(A->ops,&MatOps_Values,sizeof(struct _MatOps));

649:   PetscNewLog(A,&b);
650:   A->data = (void*)b;

652:   PetscLayoutSetUp(A->rmap);
653:   PetscLayoutSetUp(A->cmap);

655:   b->ctx                 = 0;
656:   b->vshift              = 0.0;
657:   b->vscale              = 1.0;
658:   b->managescalingshifts = PETSC_TRUE;
659:   A->assembled           = PETSC_TRUE;
660:   A->preallocated        = PETSC_FALSE;

662:   PetscObjectChangeTypeName((PetscObject)A,MATSHELL);
663:   return(0);
664: }

666: /*@C
667:    MatCreateShell - Creates a new matrix class for use with a user-defined
668:    private data storage format.

670:   Collective on MPI_Comm

672:    Input Parameters:
673: +  comm - MPI communicator
674: .  m - number of local rows (must be given)
675: .  n - number of local columns (must be given)
676: .  M - number of global rows (may be PETSC_DETERMINE)
677: .  N - number of global columns (may be PETSC_DETERMINE)
678: -  ctx - pointer to data needed by the shell matrix routines

680:    Output Parameter:
681: .  A - the matrix

683:    Level: advanced

685:   Usage:
686: $    extern int mult(Mat,Vec,Vec);
687: $    MatCreateShell(comm,m,n,M,N,ctx,&mat);
688: $    MatShellSetOperation(mat,MATOP_MULT,(void(*)(void))mult);
689: $    [ Use matrix for operations that have been set ]
690: $    MatDestroy(mat);

692:    Notes:
693:    The shell matrix type is intended to provide a simple class to use
694:    with KSP (such as, for use with matrix-free methods). You should not
695:    use the shell type if you plan to define a complete matrix class.

697:    Fortran Notes:
698:     To use this from Fortran with a ctx you must write an interface definition for this
699:     function and for MatShellGetContext() that tells Fortran the Fortran derived data type you are passing
700:     in as the ctx argument.

702:    PETSc requires that matrices and vectors being used for certain
703:    operations are partitioned accordingly.  For example, when
704:    creating a shell matrix, A, that supports parallel matrix-vector
705:    products using MatMult(A,x,y) the user should set the number
706:    of local matrix rows to be the number of local elements of the
707:    corresponding result vector, y. Note that this is information is
708:    required for use of the matrix interface routines, even though
709:    the shell matrix may not actually be physically partitioned.
710:    For example,

712: $
713: $     Vec x, y
714: $     extern int mult(Mat,Vec,Vec);
715: $     Mat A
716: $
717: $     VecCreateMPI(comm,PETSC_DECIDE,M,&y);
718: $     VecCreateMPI(comm,PETSC_DECIDE,N,&x);
719: $     VecGetLocalSize(y,&m);
720: $     VecGetLocalSize(x,&n);
721: $     MatCreateShell(comm,m,n,M,N,ctx,&A);
722: $     MatShellSetOperation(mat,MATOP_MULT,(void(*)(void))mult);
723: $     MatMult(A,x,y);
724: $     MatDestroy(A);
725: $     VecDestroy(y); VecDestroy(x);
726: $


729:    MATSHELL handles MatShift(), MatDiagonalSet(), MatDiagonalScale(), MatAXPY(), and MatScale() internally so these
730:    operations cannot be overwritten unless MatShellSetManageScalingShifts() is called.


733:     For rectangular matrices do all the scalings and shifts make sense?

735:     Developers Notes:
736:     Regarding shifting and scaling. The general form is

738:           diag(left)(vscale*A + diag(dshift) + vshift I)diag(right)

740:       The order you apply the operations is important. For example if you have a dshift then
741:       apply a MatScale(s) you get s*vscale*A + s*diag(shift). But if you first scale and then shift
742:       you get s*vscale*A + diag(shift)

744:           A is the user provided function.

746: .keywords: matrix, shell, create

748: .seealso: MatShellSetOperation(), MatHasOperation(), MatShellGetContext(), MatShellSetContext(), MATSHELL, MatShellSetManageScalingShifts()
749: @*/
750: PetscErrorCode  MatCreateShell(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,void *ctx,Mat *A)
751: {

755:   MatCreate(comm,A);
756:   MatSetSizes(*A,m,n,M,N);
757:   MatSetType(*A,MATSHELL);
758:   MatShellSetContext(*A,ctx);
759:   MatSetUp(*A);
760:   return(0);
761: }

763: /*@
764:     MatShellSetContext - sets the context for a shell matrix

766:    Logically Collective on Mat

768:     Input Parameters:
769: +   mat - the shell matrix
770: -   ctx - the context

772:    Level: advanced

774:    Fortran Notes:
775:     To use this from Fortran you must write a Fortran interface definition for this
776:     function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.

778: .seealso: MatCreateShell(), MatShellGetContext(), MatShellGetOperation()
779: @*/
780: PetscErrorCode  MatShellSetContext(Mat mat,void *ctx)
781: {
782:   Mat_Shell      *shell = (Mat_Shell*)mat->data;
784:   PetscBool      flg;

788:   PetscObjectTypeCompare((PetscObject)mat,MATSHELL,&flg);
789:   if (flg) {
790:     shell->ctx = ctx;
791:   } else SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot attach context to non-shell matrix");
792:   return(0);
793: }

795: /*@
796:     MatShellSetManageScalingShifts - Allows the user to control the scaling and shift operations of the MATSHELL. Must be called immediately
797:           after MatCreateShell()

799:    Logically Collective on Mat

801:     Input Parameter:
802: .   mat - the shell matrix

804:   Level: advanced

806: .seealso: MatCreateShell(), MatShellGetContext(), MatShellGetOperation(), MatShellSetContext(), MatShellSetOperation()
807: @*/
808: PetscErrorCode MatShellSetManageScalingShifts(Mat A)
809: {
811:   Mat_Shell      *shell;
812:   PetscBool      flg;

816:   PetscObjectTypeCompare((PetscObject)A,MATSHELL,&flg);
817:   if (!flg) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"Can only use with MATSHELL matrices");
818:   shell = (Mat_Shell*)A->data;
819:   shell->managescalingshifts = PETSC_FALSE;
820:   A->ops->diagonalset   = NULL;
821:   A->ops->diagonalscale = NULL;
822:   A->ops->scale         = NULL;
823:   A->ops->shift         = NULL;
824:   A->ops->axpy          = NULL;
825:   return(0);
826: }

828: /*@C
829:     MatShellTestMult - Compares the multiply routine provided to the MATSHELL with differencing on a given function.

831:    Logically Collective on Mat

833:     Input Parameters:
834: +   mat - the shell matrix
835: .   f - the function
836: .   base - differences are computed around this vector, see MatMFFDSetBase(), for Jacobians this is the point at which the Jacobian is being evaluated
837: -   ctx - an optional context for the function

839:    Output Parameter:
840: .   flg - PETSC_TRUE if the multiply is likely correct

842:    Options Database:
843: .   -mat_shell_test_mult_view - print if any differences are detected between the products and print the difference

845:    Level: advanced

847:    Fortran Notes:
848:     Not supported from Fortran

850: .seealso: MatCreateShell(), MatShellGetContext(), MatShellGetOperation(), MatShellTestMultTranspose()
851: @*/
852: PetscErrorCode  MatShellTestMult(Mat mat,PetscErrorCode (*f)(void*,Vec,Vec),Vec base,void *ctx,PetscBool *flg)
853: {
855:   PetscInt       m,n;
856:   Mat            mf,Dmf,Dmat,Ddiff;
857:   PetscReal      Diffnorm,Dmfnorm;
858:   PetscBool      v = PETSC_FALSE, flag = PETSC_TRUE;

862:   PetscOptionsHasName(NULL,((PetscObject)mat)->prefix,"-mat_shell_test_mult_view",&v);
863:   MatGetLocalSize(mat,&m,&n);
864:   MatCreateMFFD(PetscObjectComm((PetscObject)mat),m,n,PETSC_DECIDE,PETSC_DECIDE,&mf);
865:   MatMFFDSetFunction(mf,f,ctx);
866:   MatMFFDSetBase(mf,base,NULL);

868:   MatComputeExplicitOperator(mf,&Dmf);
869:   MatComputeExplicitOperator(mat,&Dmat);

871:   MatDuplicate(Dmat,MAT_COPY_VALUES,&Ddiff);
872:   MatAXPY(Ddiff,-1.0,Dmf,DIFFERENT_NONZERO_PATTERN);
873:   MatNorm(Ddiff,NORM_FROBENIUS,&Diffnorm);
874:   MatNorm(Dmf,NORM_FROBENIUS,&Dmfnorm);
875:   if (Diffnorm/Dmfnorm > 10*PETSC_SQRT_MACHINE_EPSILON) {
876:     flag = PETSC_FALSE;
877:     if (v) {
878:       PetscPrintf(PetscObjectComm((PetscObject)mat),"MATSHELL and matrix free multiple appear to produce different results.\n Norm Ratio %g Difference results followed by finite difference one\n",(double)(Diffnorm/Dmfnorm));
879:       MatViewFromOptions(Ddiff,(PetscObject)mat,"-mat_shell_test_mult_view");
880:       MatViewFromOptions(Dmf,(PetscObject)mat,"-mat_shell_test_mult_view");
881:       MatViewFromOptions(Dmat,(PetscObject)mat,"-mat_shell_test_mult_view");
882:     }
883:   } else if (v) {
884:     PetscPrintf(PetscObjectComm((PetscObject)mat),"MATSHELL and matrix free multiple appear to produce the same results\n");
885:   }
886:   if (flg) *flg = flag;
887:   MatDestroy(&Ddiff);
888:   MatDestroy(&mf);
889:   MatDestroy(&Dmf);
890:   MatDestroy(&Dmat);
891:   return(0);
892: }

894: /*@C
895:     MatShellTestMultTranpose - Compares the multiply transpose routine provided to the MATSHELL with differencing on a given function.

897:    Logically Collective on Mat

899:     Input Parameters:
900: +   mat - the shell matrix
901: .   f - the function
902: .   base - differences are computed around this vector, see MatMFFDSetBase(), for Jacobians this is the point at which the Jacobian is being evaluated
903: -   ctx - an optional context for the function

905:    Output Parameter:
906: .   flg - PETSC_TRUE if the multiply is likely correct

908:    Options Database:
909: .   -mat_shell_test_mult_view - print if any differences are detected between the products and print the difference

911:    Level: advanced

913:    Fortran Notes:
914:     Not supported from Fortran

916: .seealso: MatCreateShell(), MatShellGetContext(), MatShellGetOperation(), MatShellTestMult()
917: @*/
918: PetscErrorCode  MatShellTestMultTranspose(Mat mat,PetscErrorCode (*f)(void*,Vec,Vec),Vec base,void *ctx,PetscBool *flg)
919: {
921:   Vec            x,y,z;
922:   PetscInt       m,n,M,N;
923:   Mat            mf,Dmf,Dmat,Ddiff;
924:   PetscReal      Diffnorm,Dmfnorm;
925:   PetscBool      v = PETSC_FALSE, flag = PETSC_TRUE;

929:   PetscOptionsHasName(NULL,((PetscObject)mat)->prefix,"-mat_shell_test_mult_transpose_view",&v);
930:   MatCreateVecs(mat,&x,&y);
931:   VecDuplicate(y,&z);
932:   MatGetLocalSize(mat,&m,&n);
933:   MatGetSize(mat,&M,&N);
934:   MatCreateMFFD(PetscObjectComm((PetscObject)mat),m,n,M,N,&mf);
935:   MatMFFDSetFunction(mf,f,ctx);
936:   MatMFFDSetBase(mf,base,NULL);
937:   MatComputeExplicitOperator(mf,&Dmf);
938:   MatTranspose(Dmf,MAT_INPLACE_MATRIX,&Dmf);
939:   MatComputeExplicitOperatorTranspose(mat,&Dmat);

941:   MatDuplicate(Dmat,MAT_COPY_VALUES,&Ddiff);
942:   MatAXPY(Ddiff,-1.0,Dmf,DIFFERENT_NONZERO_PATTERN);
943:   MatNorm(Ddiff,NORM_FROBENIUS,&Diffnorm);
944:   MatNorm(Dmf,NORM_FROBENIUS,&Dmfnorm);
945:   if (Diffnorm/Dmfnorm > 10*PETSC_SQRT_MACHINE_EPSILON) {
946:     flag = PETSC_FALSE;
947:     if (v) {
948:       PetscPrintf(PetscObjectComm((PetscObject)mat),"MATSHELL and matrix free multiple appear to produce different results.\n Norm Ratio %g Difference results followed by finite difference one\n",(double)(Diffnorm/Dmfnorm));
949:       MatViewFromOptions(Ddiff,(PetscObject)mat,"-mat_shell_test_mult_transpose_view");
950:       MatViewFromOptions(Dmf,(PetscObject)mat,"-mat_shell_test_mult_transpose_view");
951:       MatViewFromOptions(Dmat,(PetscObject)mat,"-mat_shell_test_mult_transpose_view");
952:     }
953:   } else if (v) {
954:     PetscPrintf(PetscObjectComm((PetscObject)mat),"MATSHELL transpose and matrix free multiple appear to produce the same results\n");
955:   }
956:   if (flg) *flg = flag;
957:   MatDestroy(&mf);
958:   MatDestroy(&Dmat);
959:   MatDestroy(&Ddiff);
960:   MatDestroy(&Dmf);
961:   VecDestroy(&x);
962:   VecDestroy(&y);
963:   VecDestroy(&z);
964:   return(0);
965: }

967: /*@C
968:     MatShellSetOperation - Allows user to set a matrix operation for a shell matrix.

970:    Logically Collective on Mat

972:     Input Parameters:
973: +   mat - the shell matrix
974: .   op - the name of the operation
975: -   f - the function that provides the operation.

977:    Level: advanced

979:     Usage:
980: $      extern PetscErrorCode usermult(Mat,Vec,Vec);
981: $      MatCreateShell(comm,m,n,M,N,ctx,&A);
982: $      MatShellSetOperation(A,MATOP_MULT,(void(*)(void))usermult);

984:     Notes:
985:     See the file include/petscmat.h for a complete list of matrix
986:     operations, which all have the form MATOP_<OPERATION>, where
987:     <OPERATION> is the name (in all capital letters) of the
988:     user interface routine (e.g., MatMult() -> MATOP_MULT).

990:     All user-provided functions (except for MATOP_DESTROY) should have the same calling
991:     sequence as the usual matrix interface routines, since they
992:     are intended to be accessed via the usual matrix interface
993:     routines, e.g.,
994: $       MatMult(Mat,Vec,Vec) -> usermult(Mat,Vec,Vec)

996:     In particular each function MUST return an error code of 0 on success and
997:     nonzero on failure.

999:     Within each user-defined routine, the user should call
1000:     MatShellGetContext() to obtain the user-defined context that was
1001:     set by MatCreateShell().

1003:     Fortran Notes:
1004:     For MatCreateVecs() the user code should check if the input left or right matrix is -1 and in that case not
1005:        generate a matrix. See src/mat/examples/tests/ex120f.F

1007:     Use MatSetOperation() to set an operation for any matrix type

1009: .keywords: matrix, shell, set, operation

1011: .seealso: MatCreateShell(), MatShellGetContext(), MatShellGetOperation(), MatShellSetContext(), MatSetOperation(), MatShellSetManageScalingShifts()
1012: @*/
1013: PetscErrorCode MatShellSetOperation(Mat mat,MatOperation op,void (*f)(void))
1014: {
1015:   PetscBool      flg;
1016:   Mat_Shell      *shell;

1021:   PetscObjectTypeCompare((PetscObject)mat,MATSHELL,&flg);
1022:   if (!flg) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Can only use with MATSHELL matrices");
1023:   shell = (Mat_Shell*)mat->data;

1025:   switch (op) {
1026:   case MATOP_DESTROY:
1027:     shell->ops->destroy = (PetscErrorCode (*)(Mat))f;
1028:     break;
1029:   case MATOP_VIEW:
1030:     if (!mat->ops->viewnative) {
1031:       mat->ops->viewnative = mat->ops->view;
1032:     }
1033:     mat->ops->view = (PetscErrorCode (*)(Mat,PetscViewer))f;
1034:     break;
1035:   case MATOP_COPY:
1036:     shell->ops->copy = (PetscErrorCode (*)(Mat,Mat,MatStructure))f;
1037:     break;
1038:   case MATOP_DIAGONAL_SET:
1039:   case MATOP_DIAGONAL_SCALE:
1040:   case MATOP_SHIFT:
1041:   case MATOP_SCALE:
1042:   case MATOP_AXPY:
1043:     if (shell->managescalingshifts) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"MATSHELL is managing scalings and shifts, see MatShellSetManageScalingShifts()");
1044:     (((void(**)(void))mat->ops)[op]) = f;
1045:     break;
1046:   case MATOP_GET_DIAGONAL:
1047:     if (shell->managescalingshifts) {
1048:       shell->ops->getdiagonal = (PetscErrorCode (*)(Mat,Vec))f;
1049:       mat->ops->getdiagonal   = MatGetDiagonal_Shell;
1050:     } else {
1051:       shell->ops->getdiagonal = NULL;
1052:       mat->ops->getdiagonal   = (PetscErrorCode (*)(Mat,Vec))f;
1053:     }
1054:     break;
1055:   case MATOP_MULT:
1056:     if (shell->managescalingshifts) {
1057:       shell->ops->mult = (PetscErrorCode (*)(Mat,Vec,Vec))f;
1058:       mat->ops->mult   = MatMult_Shell;
1059:     } else {
1060:       shell->ops->mult = NULL;
1061:       mat->ops->mult   = (PetscErrorCode (*)(Mat,Vec,Vec))f;
1062:     }
1063:     break;
1064:   case MATOP_MULT_TRANSPOSE:
1065:     if (shell->managescalingshifts) {
1066:       shell->ops->multtranspose = (PetscErrorCode (*)(Mat,Vec,Vec))f;
1067:       mat->ops->multtranspose   = MatMultTranspose_Shell;
1068:     } else {
1069:       shell->ops->multtranspose = NULL;
1070:       mat->ops->multtranspose   = (PetscErrorCode (*)(Mat,Vec,Vec))f;
1071:     }
1072:     break;
1073:   default:
1074:     (((void(**)(void))mat->ops)[op]) = f;
1075:     break;
1076:   }
1077:   return(0);
1078: }

1080: /*@C
1081:     MatShellGetOperation - Gets a matrix function for a shell matrix.

1083:     Not Collective

1085:     Input Parameters:
1086: +   mat - the shell matrix
1087: -   op - the name of the operation

1089:     Output Parameter:
1090: .   f - the function that provides the operation.

1092:     Level: advanced

1094:     Notes:
1095:     See the file include/petscmat.h for a complete list of matrix
1096:     operations, which all have the form MATOP_<OPERATION>, where
1097:     <OPERATION> is the name (in all capital letters) of the
1098:     user interface routine (e.g., MatMult() -> MATOP_MULT).

1100:     All user-provided functions have the same calling
1101:     sequence as the usual matrix interface routines, since they
1102:     are intended to be accessed via the usual matrix interface
1103:     routines, e.g.,
1104: $       MatMult(Mat,Vec,Vec) -> usermult(Mat,Vec,Vec)

1106:     Within each user-defined routine, the user should call
1107:     MatShellGetContext() to obtain the user-defined context that was
1108:     set by MatCreateShell().

1110: .keywords: matrix, shell, set, operation

1112: .seealso: MatCreateShell(), MatShellGetContext(), MatShellSetOperation(), MatShellSetContext()
1113: @*/
1114: PetscErrorCode MatShellGetOperation(Mat mat,MatOperation op,void(**f)(void))
1115: {
1116:   PetscBool      flg;
1117:   Mat_Shell      *shell;

1122:   PetscObjectTypeCompare((PetscObject)mat,MATSHELL,&flg);
1123:   if (!flg) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Can only use with MATSHELL matrices");
1124:   shell = (Mat_Shell*)mat->data;

1126:   switch (op) {
1127:   case MATOP_DESTROY:
1128:     *f = (void (*)(void))shell->ops->destroy;
1129:     break;
1130:   case MATOP_VIEW:
1131:     *f = (void (*)(void))mat->ops->view;
1132:     break;
1133:   case MATOP_COPY:
1134:     *f = (void (*)(void))shell->ops->copy;
1135:     break;
1136:   case MATOP_DIAGONAL_SET:
1137:   case MATOP_DIAGONAL_SCALE:
1138:   case MATOP_SHIFT:
1139:   case MATOP_SCALE:
1140:   case MATOP_AXPY:
1141:     *f = (((void (**)(void))mat->ops)[op]);
1142:     break;
1143:   case MATOP_GET_DIAGONAL:
1144:     if (shell->ops->getdiagonal)
1145:       *f = (void (*)(void))shell->ops->getdiagonal;
1146:     else
1147:       *f = (((void (**)(void))mat->ops)[op]);
1148:     break;
1149:   case MATOP_MULT:
1150:     if (shell->ops->mult)
1151:       *f = (void (*)(void))shell->ops->mult;
1152:     else
1153:       *f = (((void (**)(void))mat->ops)[op]);
1154:     break;
1155:   case MATOP_MULT_TRANSPOSE:
1156:     if (shell->ops->multtranspose)
1157:       *f = (void (*)(void))shell->ops->multtranspose;
1158:     else
1159:       *f = (((void (**)(void))mat->ops)[op]);
1160:     break;
1161:   default:
1162:     *f = (((void (**)(void))mat->ops)[op]);
1163:   }
1164:   return(0);
1165: }