Actual source code: shell.c
petsc-3.6.1 2015-08-06
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> /*I "petscmat.h" I*/
9: #include <petsc/private/vecimpl.h>
11: typedef struct {
12: PetscErrorCode (*destroy)(Mat);
13: PetscErrorCode (*mult)(Mat,Vec,Vec);
14: PetscErrorCode (*multtranspose)(Mat,Vec,Vec);
15: PetscErrorCode (*getdiagonal)(Mat,Vec);
17: PetscScalar vscale,vshift;
18: Vec dshift;
19: Vec left,right;
20: Vec dshift_owned,left_owned,right_owned;
21: Vec left_work,right_work;
22: Vec left_add_work,right_add_work;
23: PetscBool usingscaled;
24: void *ctx;
25: } Mat_Shell;
26: /*
27: The most general expression for the matrix is
29: S = L (a A + B) R
31: where
32: A is the matrix defined by the user's function
33: a is a scalar multiple
34: L is left scaling
35: R is right scaling
36: B is a diagonal shift defined by
37: diag(dshift) if the vector dshift is non-NULL
38: vscale*identity otherwise
40: The following identities apply:
42: Scale by c:
43: c [L (a A + B) R] = L [(a c) A + c B] R
45: Shift by c:
46: [L (a A + B) R] + c = L [a A + (B + c Linv Rinv)] R
48: Diagonal scaling is achieved by simply multiplying with existing L and R vectors
50: In the data structure:
52: vscale=1.0 means no special scaling will be applied
53: dshift=NULL means a constant diagonal shift (fall back to vshift)
54: vshift=0.0 means no constant diagonal shift, note that vshift is only used if dshift is NULL
55: */
57: static PetscErrorCode MatMult_Shell(Mat,Vec,Vec);
58: static PetscErrorCode MatMultTranspose_Shell(Mat,Vec,Vec);
59: static PetscErrorCode MatGetDiagonal_Shell(Mat,Vec);
63: static PetscErrorCode MatShellUseScaledMethods(Mat Y)
64: {
65: Mat_Shell *shell = (Mat_Shell*)Y->data;
68: if (shell->usingscaled) return(0);
69: shell->mult = Y->ops->mult;
70: Y->ops->mult = MatMult_Shell;
71: if (Y->ops->multtranspose) {
72: shell->multtranspose = Y->ops->multtranspose;
73: Y->ops->multtranspose = MatMultTranspose_Shell;
74: }
75: if (Y->ops->getdiagonal) {
76: shell->getdiagonal = Y->ops->getdiagonal;
77: Y->ops->getdiagonal = MatGetDiagonal_Shell;
78: }
79: shell->usingscaled = PETSC_TRUE;
80: return(0);
81: }
85: static PetscErrorCode MatShellPreScaleLeft(Mat A,Vec x,Vec *xx)
86: {
87: Mat_Shell *shell = (Mat_Shell*)A->data;
91: *xx = NULL;
92: if (!shell->left) {
93: *xx = x;
94: } else {
95: if (!shell->left_work) {VecDuplicate(shell->left,&shell->left_work);}
96: VecPointwiseMult(shell->left_work,x,shell->left);
97: *xx = shell->left_work;
98: }
99: return(0);
100: }
104: static PetscErrorCode MatShellPreScaleRight(Mat A,Vec x,Vec *xx)
105: {
106: Mat_Shell *shell = (Mat_Shell*)A->data;
110: *xx = NULL;
111: if (!shell->right) {
112: *xx = x;
113: } else {
114: if (!shell->right_work) {VecDuplicate(shell->right,&shell->right_work);}
115: VecPointwiseMult(shell->right_work,x,shell->right);
116: *xx = shell->right_work;
117: }
118: return(0);
119: }
123: static PetscErrorCode MatShellPostScaleLeft(Mat A,Vec x)
124: {
125: Mat_Shell *shell = (Mat_Shell*)A->data;
129: if (shell->left) {VecPointwiseMult(x,x,shell->left);}
130: return(0);
131: }
135: static PetscErrorCode MatShellPostScaleRight(Mat A,Vec x)
136: {
137: Mat_Shell *shell = (Mat_Shell*)A->data;
141: if (shell->right) {VecPointwiseMult(x,x,shell->right);}
142: return(0);
143: }
147: static PetscErrorCode MatShellShiftAndScale(Mat A,Vec X,Vec Y)
148: {
149: Mat_Shell *shell = (Mat_Shell*)A->data;
153: if (shell->dshift) { /* get arrays because there is no VecPointwiseMultAdd() */
154: PetscInt i,m;
155: const PetscScalar *x,*d;
156: PetscScalar *y;
157: VecGetLocalSize(X,&m);
158: VecGetArrayRead(shell->dshift,&d);
159: VecGetArrayRead(X,&x);
160: VecGetArray(Y,&y);
161: for (i=0; i<m; i++) y[i] = shell->vscale*y[i] + d[i]*x[i];
162: VecRestoreArrayRead(shell->dshift,&d);
163: VecRestoreArrayRead(X,&x);
164: VecRestoreArray(Y,&y);
165: } else if (PetscAbsScalar(shell->vshift) != 0) {
166: VecAXPBY(Y,shell->vshift,shell->vscale,X);
167: } else if (shell->vscale != 1.0) {
168: VecScale(Y,shell->vscale);
169: }
170: return(0);
171: }
175: /*@
176: MatShellGetContext - Returns the user-provided context associated with a shell matrix.
178: Not Collective
180: Input Parameter:
181: . mat - the matrix, should have been created with MatCreateShell()
183: Output Parameter:
184: . ctx - the user provided context
186: Level: advanced
188: Notes:
189: This routine is intended for use within various shell matrix routines,
190: as set with MatShellSetOperation().
192: .keywords: matrix, shell, get, context
194: .seealso: MatCreateShell(), MatShellSetOperation(), MatShellSetContext()
195: @*/
196: PetscErrorCode MatShellGetContext(Mat mat,void *ctx)
197: {
199: PetscBool flg;
204: PetscObjectTypeCompare((PetscObject)mat,MATSHELL,&flg);
205: if (flg) *(void**)ctx = ((Mat_Shell*)(mat->data))->ctx;
206: else SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot get context from non-shell matrix");
207: return(0);
208: }
212: PetscErrorCode MatDestroy_Shell(Mat mat)
213: {
215: Mat_Shell *shell = (Mat_Shell*)mat->data;
218: if (shell->destroy) {
219: (*shell->destroy)(mat);
220: }
221: VecDestroy(&shell->left_owned);
222: VecDestroy(&shell->right_owned);
223: VecDestroy(&shell->dshift_owned);
224: VecDestroy(&shell->left_work);
225: VecDestroy(&shell->right_work);
226: VecDestroy(&shell->left_add_work);
227: VecDestroy(&shell->right_add_work);
228: PetscFree(mat->data);
229: return(0);
230: }
234: PetscErrorCode MatMult_Shell(Mat A,Vec x,Vec y)
235: {
236: Mat_Shell *shell = (Mat_Shell*)A->data;
238: Vec xx;
241: MatShellPreScaleRight(A,x,&xx);
242: (*shell->mult)(A,xx,y);
243: MatShellShiftAndScale(A,xx,y);
244: MatShellPostScaleLeft(A,y);
245: return(0);
246: }
250: PetscErrorCode MatMultAdd_Shell(Mat A,Vec x,Vec y,Vec z)
251: {
252: Mat_Shell *shell = (Mat_Shell*)A->data;
256: if (y == z) {
257: if (!shell->right_add_work) {VecDuplicate(z,&shell->right_add_work);}
258: MatMult(A,x,shell->right_add_work);
259: VecAXPY(z,1.0,shell->right_add_work);
260: } else {
261: MatMult(A,x,z);
262: VecAXPY(z,1.0,y);
263: }
264: return(0);
265: }
269: PetscErrorCode MatMultTranspose_Shell(Mat A,Vec x,Vec y)
270: {
271: Mat_Shell *shell = (Mat_Shell*)A->data;
273: Vec xx;
276: MatShellPreScaleLeft(A,x,&xx);
277: (*shell->multtranspose)(A,xx,y);
278: MatShellShiftAndScale(A,xx,y);
279: MatShellPostScaleRight(A,y);
280: return(0);
281: }
285: PetscErrorCode MatMultTransposeAdd_Shell(Mat A,Vec x,Vec y,Vec z)
286: {
287: Mat_Shell *shell = (Mat_Shell*)A->data;
291: if (y == z) {
292: if (!shell->left_add_work) {VecDuplicate(z,&shell->left_add_work);}
293: MatMultTranspose(A,x,shell->left_add_work);
294: VecWAXPY(z,1.0,shell->left_add_work,y);
295: } else {
296: MatMultTranspose(A,x,z);
297: VecAXPY(z,1.0,y);
298: }
299: return(0);
300: }
304: PetscErrorCode MatGetDiagonal_Shell(Mat A,Vec v)
305: {
306: Mat_Shell *shell = (Mat_Shell*)A->data;
310: (*shell->getdiagonal)(A,v);
311: VecScale(v,shell->vscale);
312: if (shell->dshift) {
313: VecPointwiseMult(v,v,shell->dshift);
314: } else {
315: VecShift(v,shell->vshift);
316: }
317: if (shell->left) {VecPointwiseMult(v,v,shell->left);}
318: if (shell->right) {VecPointwiseMult(v,v,shell->right);}
319: return(0);
320: }
324: PetscErrorCode MatShift_Shell(Mat Y,PetscScalar a)
325: {
326: Mat_Shell *shell = (Mat_Shell*)Y->data;
330: if (shell->left || shell->right || shell->dshift) {
331: if (!shell->dshift) {
332: if (!shell->dshift_owned) {VecDuplicate(shell->left ? shell->left : shell->right, &shell->dshift_owned);}
333: shell->dshift = shell->dshift_owned;
334: VecSet(shell->dshift,shell->vshift+a);
335: } else {VecScale(shell->dshift,a);}
336: if (shell->left) {VecPointwiseDivide(shell->dshift,shell->dshift,shell->left);}
337: if (shell->right) {VecPointwiseDivide(shell->dshift,shell->dshift,shell->right);}
338: } else shell->vshift += a;
339: MatShellUseScaledMethods(Y);
340: return(0);
341: }
345: PetscErrorCode MatScale_Shell(Mat Y,PetscScalar a)
346: {
347: Mat_Shell *shell = (Mat_Shell*)Y->data;
351: shell->vscale *= a;
352: if (shell->dshift) {
353: VecScale(shell->dshift,a);
354: } else shell->vshift *= a;
355: MatShellUseScaledMethods(Y);
356: return(0);
357: }
361: static PetscErrorCode MatDiagonalScale_Shell(Mat Y,Vec left,Vec right)
362: {
363: Mat_Shell *shell = (Mat_Shell*)Y->data;
367: if (left) {
368: if (!shell->left_owned) {VecDuplicate(left,&shell->left_owned);}
369: if (shell->left) {
370: VecPointwiseMult(shell->left,shell->left,left);
371: } else {
372: shell->left = shell->left_owned;
373: VecCopy(left,shell->left);
374: }
375: }
376: if (right) {
377: if (!shell->right_owned) {VecDuplicate(right,&shell->right_owned);}
378: if (shell->right) {
379: VecPointwiseMult(shell->right,shell->right,right);
380: } else {
381: shell->right = shell->right_owned;
382: VecCopy(right,shell->right);
383: }
384: }
385: MatShellUseScaledMethods(Y);
386: return(0);
387: }
391: PetscErrorCode MatAssemblyEnd_Shell(Mat Y,MatAssemblyType t)
392: {
393: Mat_Shell *shell = (Mat_Shell*)Y->data;
396: if (t == MAT_FINAL_ASSEMBLY) {
397: shell->vshift = 0.0;
398: shell->vscale = 1.0;
399: shell->dshift = NULL;
400: shell->left = NULL;
401: shell->right = NULL;
402: if (shell->mult) {
403: Y->ops->mult = shell->mult;
404: shell->mult = NULL;
405: }
406: if (shell->multtranspose) {
407: Y->ops->multtranspose = shell->multtranspose;
408: shell->multtranspose = NULL;
409: }
410: if (shell->getdiagonal) {
411: Y->ops->getdiagonal = shell->getdiagonal;
412: shell->getdiagonal = NULL;
413: }
414: shell->usingscaled = PETSC_FALSE;
415: }
416: return(0);
417: }
419: extern PetscErrorCode MatConvert_Shell(Mat, MatType,MatReuse,Mat*);
421: static struct _MatOps MatOps_Values = {0,
422: 0,
423: 0,
424: 0,
425: /* 4*/ 0,
426: 0,
427: 0,
428: 0,
429: 0,
430: 0,
431: /*10*/ 0,
432: 0,
433: 0,
434: 0,
435: 0,
436: /*15*/ 0,
437: 0,
438: 0,
439: MatDiagonalScale_Shell,
440: 0,
441: /*20*/ 0,
442: MatAssemblyEnd_Shell,
443: 0,
444: 0,
445: /*24*/ 0,
446: 0,
447: 0,
448: 0,
449: 0,
450: /*29*/ 0,
451: 0,
452: 0,
453: 0,
454: 0,
455: /*34*/ 0,
456: 0,
457: 0,
458: 0,
459: 0,
460: /*39*/ 0,
461: 0,
462: 0,
463: 0,
464: 0,
465: /*44*/ 0,
466: MatScale_Shell,
467: MatShift_Shell,
468: 0,
469: 0,
470: /*49*/ 0,
471: 0,
472: 0,
473: 0,
474: 0,
475: /*54*/ 0,
476: 0,
477: 0,
478: 0,
479: 0,
480: /*59*/ 0,
481: MatDestroy_Shell,
482: 0,
483: 0,
484: 0,
485: /*64*/ 0,
486: 0,
487: 0,
488: 0,
489: 0,
490: /*69*/ 0,
491: 0,
492: MatConvert_Shell,
493: 0,
494: 0,
495: /*74*/ 0,
496: 0,
497: 0,
498: 0,
499: 0,
500: /*79*/ 0,
501: 0,
502: 0,
503: 0,
504: 0,
505: /*84*/ 0,
506: 0,
507: 0,
508: 0,
509: 0,
510: /*89*/ 0,
511: 0,
512: 0,
513: 0,
514: 0,
515: /*94*/ 0,
516: 0,
517: 0,
518: 0,
519: 0,
520: /*99*/ 0,
521: 0,
522: 0,
523: 0,
524: 0,
525: /*104*/ 0,
526: 0,
527: 0,
528: 0,
529: 0,
530: /*109*/ 0,
531: 0,
532: 0,
533: 0,
534: 0,
535: /*114*/ 0,
536: 0,
537: 0,
538: 0,
539: 0,
540: /*119*/ 0,
541: 0,
542: 0,
543: 0,
544: 0,
545: /*124*/ 0,
546: 0,
547: 0,
548: 0,
549: 0,
550: /*129*/ 0,
551: 0,
552: 0,
553: 0,
554: 0,
555: /*134*/ 0,
556: 0,
557: 0,
558: 0,
559: 0,
560: /*139*/ 0,
561: 0,
562: 0
563: };
565: /*MC
566: MATSHELL - MATSHELL = "shell" - A matrix type to be used to define your own matrix type -- perhaps matrix free.
568: Level: advanced
570: .seealso: MatCreateShell
571: M*/
575: PETSC_EXTERN PetscErrorCode MatCreate_Shell(Mat A)
576: {
577: Mat_Shell *b;
581: PetscMemcpy(A->ops,&MatOps_Values,sizeof(struct _MatOps));
583: PetscNewLog(A,&b);
584: A->data = (void*)b;
586: PetscLayoutSetUp(A->rmap);
587: PetscLayoutSetUp(A->cmap);
589: b->ctx = 0;
590: b->vshift = 0.0;
591: b->vscale = 1.0;
592: b->mult = 0;
593: b->multtranspose = 0;
594: b->getdiagonal = 0;
595: A->assembled = PETSC_TRUE;
596: A->preallocated = PETSC_FALSE;
598: PetscObjectChangeTypeName((PetscObject)A,MATSHELL);
599: return(0);
600: }
604: /*@C
605: MatCreateShell - Creates a new matrix class for use with a user-defined
606: private data storage format.
608: Collective on MPI_Comm
610: Input Parameters:
611: + comm - MPI communicator
612: . m - number of local rows (must be given)
613: . n - number of local columns (must be given)
614: . M - number of global rows (may be PETSC_DETERMINE)
615: . N - number of global columns (may be PETSC_DETERMINE)
616: - ctx - pointer to data needed by the shell matrix routines
618: Output Parameter:
619: . A - the matrix
621: Level: advanced
623: Usage:
624: $ extern int mult(Mat,Vec,Vec);
625: $ MatCreateShell(comm,m,n,M,N,ctx,&mat);
626: $ MatShellSetOperation(mat,MATOP_MULT,(void(*)(void))mult);
627: $ [ Use matrix for operations that have been set ]
628: $ MatDestroy(mat);
630: Notes:
631: The shell matrix type is intended to provide a simple class to use
632: with KSP (such as, for use with matrix-free methods). You should not
633: use the shell type if you plan to define a complete matrix class.
635: Fortran Notes: The context can only be an integer or a PetscObject
636: unfortunately it cannot be a Fortran array or derived type.
638: PETSc requires that matrices and vectors being used for certain
639: operations are partitioned accordingly. For example, when
640: creating a shell matrix, A, that supports parallel matrix-vector
641: products using MatMult(A,x,y) the user should set the number
642: of local matrix rows to be the number of local elements of the
643: corresponding result vector, y. Note that this is information is
644: required for use of the matrix interface routines, even though
645: the shell matrix may not actually be physically partitioned.
646: For example,
648: $
649: $ Vec x, y
650: $ extern int mult(Mat,Vec,Vec);
651: $ Mat A
652: $
653: $ VecCreateMPI(comm,PETSC_DECIDE,M,&y);
654: $ VecCreateMPI(comm,PETSC_DECIDE,N,&x);
655: $ VecGetLocalSize(y,&m);
656: $ VecGetLocalSize(x,&n);
657: $ MatCreateShell(comm,m,n,M,N,ctx,&A);
658: $ MatShellSetOperation(mat,MATOP_MULT,(void(*)(void))mult);
659: $ MatMult(A,x,y);
660: $ MatDestroy(A);
661: $ VecDestroy(y); VecDestroy(x);
662: $
664: .keywords: matrix, shell, create
666: .seealso: MatShellSetOperation(), MatHasOperation(), MatShellGetContext(), MatShellSetContext()
667: @*/
668: PetscErrorCode MatCreateShell(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,void *ctx,Mat *A)
669: {
673: MatCreate(comm,A);
674: MatSetSizes(*A,m,n,M,N);
675: MatSetType(*A,MATSHELL);
676: MatShellSetContext(*A,ctx);
677: MatSetUp(*A);
678: return(0);
679: }
683: /*@
684: MatShellSetContext - sets the context for a shell matrix
686: Logically Collective on Mat
688: Input Parameters:
689: + mat - the shell matrix
690: - ctx - the context
692: Level: advanced
694: Fortran Notes: The context can only be an integer or a PetscObject
695: unfortunately it cannot be a Fortran array or derived type.
697: .seealso: MatCreateShell(), MatShellGetContext(), MatShellGetOperation()
698: @*/
699: PetscErrorCode MatShellSetContext(Mat mat,void *ctx)
700: {
701: Mat_Shell *shell = (Mat_Shell*)mat->data;
703: PetscBool flg;
707: PetscObjectTypeCompare((PetscObject)mat,MATSHELL,&flg);
708: if (flg) {
709: shell->ctx = ctx;
710: } else SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot attach context to non-shell matrix");
711: return(0);
712: }
716: /*@C
717: MatShellSetOperation - Allows user to set a matrix operation for
718: a shell matrix.
720: Logically Collective on Mat
722: Input Parameters:
723: + mat - the shell matrix
724: . op - the name of the operation
725: - f - the function that provides the operation.
727: Level: advanced
729: Usage:
730: $ extern PetscErrorCode usermult(Mat,Vec,Vec);
731: $ MatCreateShell(comm,m,n,M,N,ctx,&A);
732: $ MatShellSetOperation(A,MATOP_MULT,(void(*)(void))usermult);
734: Notes:
735: See the file include/petscmat.h for a complete list of matrix
736: operations, which all have the form MATOP_<OPERATION>, where
737: <OPERATION> is the name (in all capital letters) of the
738: user interface routine (e.g., MatMult() -> MATOP_MULT).
740: All user-provided functions (execept for MATOP_DESTROY) should have the same calling
741: sequence as the usual matrix interface routines, since they
742: are intended to be accessed via the usual matrix interface
743: routines, e.g.,
744: $ MatMult(Mat,Vec,Vec) -> usermult(Mat,Vec,Vec)
746: In particular each function MUST return an error code of 0 on success and
747: nonzero on failure.
749: Within each user-defined routine, the user should call
750: MatShellGetContext() to obtain the user-defined context that was
751: set by MatCreateShell().
753: Fortran Notes: For MatCreateVecs() the user code should check if the input left or right matrix is -1 and in that case not
754: generate a matrix. See src/mat/examples/tests/ex120f.F
756: .keywords: matrix, shell, set, operation
758: .seealso: MatCreateShell(), MatShellGetContext(), MatShellGetOperation(), MatShellSetContext()
759: @*/
760: PetscErrorCode MatShellSetOperation(Mat mat,MatOperation op,void (*f)(void))
761: {
763: PetscBool flg;
767: switch (op) {
768: case MATOP_DESTROY:
769: PetscObjectTypeCompare((PetscObject)mat,MATSHELL,&flg);
770: if (flg) {
771: Mat_Shell *shell = (Mat_Shell*)mat->data;
772: shell->destroy = (PetscErrorCode (*)(Mat))f;
773: } else mat->ops->destroy = (PetscErrorCode (*)(Mat))f;
774: break;
775: case MATOP_VIEW:
776: mat->ops->view = (PetscErrorCode (*)(Mat,PetscViewer))f;
777: break;
778: case MATOP_MULT:
779: mat->ops->mult = (PetscErrorCode (*)(Mat,Vec,Vec))f;
780: if (!mat->ops->multadd) mat->ops->multadd = MatMultAdd_Shell;
781: break;
782: case MATOP_MULT_TRANSPOSE:
783: mat->ops->multtranspose = (PetscErrorCode (*)(Mat,Vec,Vec))f;
784: if (!mat->ops->multtransposeadd) mat->ops->multtransposeadd = MatMultTransposeAdd_Shell;
785: break;
786: default:
787: (((void(**)(void))mat->ops)[op]) = f;
788: }
789: return(0);
790: }
794: /*@C
795: MatShellGetOperation - Gets a matrix function for a shell matrix.
797: Not Collective
799: Input Parameters:
800: + mat - the shell matrix
801: - op - the name of the operation
803: Output Parameter:
804: . f - the function that provides the operation.
806: Level: advanced
808: Notes:
809: See the file include/petscmat.h for a complete list of matrix
810: operations, which all have the form MATOP_<OPERATION>, where
811: <OPERATION> is the name (in all capital letters) of the
812: user interface routine (e.g., MatMult() -> MATOP_MULT).
814: All user-provided functions have the same calling
815: sequence as the usual matrix interface routines, since they
816: are intended to be accessed via the usual matrix interface
817: routines, e.g.,
818: $ MatMult(Mat,Vec,Vec) -> usermult(Mat,Vec,Vec)
820: Within each user-defined routine, the user should call
821: MatShellGetContext() to obtain the user-defined context that was
822: set by MatCreateShell().
824: .keywords: matrix, shell, set, operation
826: .seealso: MatCreateShell(), MatShellGetContext(), MatShellSetOperation(), MatShellSetContext()
827: @*/
828: PetscErrorCode MatShellGetOperation(Mat mat,MatOperation op,void(**f)(void))
829: {
831: PetscBool flg;
835: if (op == MATOP_DESTROY) {
836: PetscObjectTypeCompare((PetscObject)mat,MATSHELL,&flg);
837: if (flg) {
838: Mat_Shell *shell = (Mat_Shell*)mat->data;
839: *f = (void (*)(void))shell->destroy;
840: } else {
841: *f = (void (*)(void))mat->ops->destroy;
842: }
843: } else if (op == MATOP_VIEW) {
844: *f = (void (*)(void))mat->ops->view;
845: } else {
846: *f = (((void (**)(void))mat->ops)[op]);
847: }
848: return(0);
849: }