Actual source code: shell.c
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 <private/matimpl.h> /*I "petscmat.h" I*/
9: #include <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);
16: PetscScalar vscale,vshift;
17: Vec dshift;
18: Vec left,right;
19: Vec dshift_owned,left_owned,right_owned;
20: Vec left_work,right_work;
21: PetscBool usingscaled;
22: void *ctx;
23: } Mat_Shell;
24: /*
25: The most general expression for the matrix is
27: S = L (a A + B) R
29: where
30: A is the matrix defined by the user's function
31: a is a scalar multiple
32: L is left scaling
33: R is right scaling
34: B is a diagonal shift defined by
35: diag(dshift) if the vector dshift is non-NULL
36: vscale*identity otherwise
38: The following identities apply:
40: Scale by c:
41: c [L (a A + B) R] = L [(a c) A + c B] R
43: Shift by c:
44: [L (a A + B) R] + c = L [a A + (B + c Linv Rinv)] R
46: Diagonal scaling is achieved by simply multiplying with existing L and R vectors
48: In the data structure:
50: vscale=1.0 means no special scaling will be applied
51: dshift=NULL means a constant diagonal shift (fall back to vshift)
52: vshift=0.0 means no constant diagonal shift, note that vshift is only used if dshift is NULL
53: */
55: static PetscErrorCode MatMult_Shell(Mat,Vec,Vec);
56: static PetscErrorCode MatMultTranspose_Shell(Mat,Vec,Vec);
57: static PetscErrorCode MatGetDiagonal_Shell(Mat,Vec);
61: static PetscErrorCode MatShellUseScaledMethods(Mat Y)
62: {
63: Mat_Shell *shell = (Mat_Shell*)Y->data;
66: if (shell->usingscaled) return(0);
67: shell->mult = Y->ops->mult;
68: Y->ops->mult = MatMult_Shell;
69: if (Y->ops->multtranspose) {
70: shell->multtranspose = Y->ops->multtranspose;
71: Y->ops->multtranspose = MatMultTranspose_Shell;
72: }
73: if (Y->ops->getdiagonal) {
74: shell->getdiagonal = Y->ops->getdiagonal;
75: Y->ops->getdiagonal = MatGetDiagonal_Shell;
76: }
77: shell->usingscaled = PETSC_TRUE;
78: return(0);
79: }
83: static PetscErrorCode MatShellPreScaleLeft(Mat A,Vec x,Vec *xx)
84: {
85: Mat_Shell *shell = (Mat_Shell*)A->data;
89: *xx = PETSC_NULL;
90: if (!shell->left) {
91: *xx = x;
92: } else {
93: if (!shell->left_work) {VecDuplicate(shell->left,&shell->left_work);}
94: VecPointwiseMult(shell->left_work,x,shell->left);
95: *xx = shell->left_work;
96: }
97: return(0);
98: }
102: static PetscErrorCode MatShellPreScaleRight(Mat A,Vec x,Vec *xx)
103: {
104: Mat_Shell *shell = (Mat_Shell*)A->data;
108: *xx = PETSC_NULL;
109: if (!shell->right) {
110: *xx = x;
111: } else {
112: if (!shell->right_work) {VecDuplicate(shell->right,&shell->right_work);}
113: VecPointwiseMult(shell->right_work,x,shell->right);
114: *xx = shell->right_work;
115: }
116: return(0);
117: }
121: static PetscErrorCode MatShellPostScaleLeft(Mat A,Vec x)
122: {
123: Mat_Shell *shell = (Mat_Shell*)A->data;
127: if (shell->left) {VecPointwiseMult(x,x,shell->left);}
128: return(0);
129: }
133: static PetscErrorCode MatShellPostScaleRight(Mat A,Vec x)
134: {
135: Mat_Shell *shell = (Mat_Shell*)A->data;
139: if (shell->right) {VecPointwiseMult(x,x,shell->right);}
140: return(0);
141: }
145: static PetscErrorCode MatShellShiftAndScale(Mat A,Vec X,Vec Y)
146: {
147: Mat_Shell *shell = (Mat_Shell*)A->data;
151: if (shell->dshift) { /* get arrays because there is no VecPointwiseMultAdd() */
152: PetscInt i,m;
153: const PetscScalar *x,*d;
154: PetscScalar *y;
155: VecGetLocalSize(X,&m);
156: VecGetArrayRead(shell->dshift,&d);
157: VecGetArrayRead(X,&x);
158: VecGetArray(Y,&y);
159: for (i=0; i<m; i++) y[i] = shell->vscale*y[i] + d[i]*x[i];
160: VecRestoreArrayRead(shell->dshift,&d);
161: VecRestoreArrayRead(X,&x);
162: VecRestoreArray(Y,&y);
163: } else if (PetscAbsScalar(shell->vshift) != 0) {
164: VecAXPBY(Y,shell->vshift,shell->vscale,X);
165: } else if (shell->vscale != 1.0) {
166: VecScale(Y,shell->vscale);
167: }
168: return(0);
169: }
173: /*@C
174: MatShellGetContext - Returns the user-provided context associated with a shell matrix.
176: Not Collective
178: Input Parameter:
179: . mat - the matrix, should have been created with MatCreateShell()
181: Output Parameter:
182: . ctx - the user provided context
184: Level: advanced
186: Notes:
187: This routine is intended for use within various shell matrix routines,
188: as set with MatShellSetOperation().
189:
190: .keywords: matrix, shell, get, context
192: .seealso: MatCreateShell(), MatShellSetOperation(), MatShellSetContext()
193: @*/
194: PetscErrorCode MatShellGetContext(Mat mat,void *ctx)
195: {
197: PetscBool flg;
202: PetscTypeCompare((PetscObject)mat,MATSHELL,&flg);
203: if (flg) *(void**)ctx = ((Mat_Shell*)(mat->data))->ctx;
204: else SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_SUP,"Cannot get context from non-shell matrix");
205: return(0);
206: }
210: PetscErrorCode MatDestroy_Shell(Mat mat)
211: {
213: Mat_Shell *shell = (Mat_Shell*)mat->data;
216: if (shell->destroy) {
217: (*shell->destroy)(mat);
218: }
219: VecDestroy(&shell->left_owned);
220: VecDestroy(&shell->right_owned);
221: VecDestroy(&shell->dshift_owned);
222: VecDestroy(&shell->left_work);
223: VecDestroy(&shell->right_work);
224: PetscFree(mat->data);
225: return(0);
226: }
230: PetscErrorCode MatMult_Shell(Mat A,Vec x,Vec y)
231: {
232: Mat_Shell *shell = (Mat_Shell*)A->data;
234: Vec xx;
237: MatShellPreScaleRight(A,x,&xx);
238: (*shell->mult)(A,xx,y);
239: MatShellShiftAndScale(A,xx,y);
240: MatShellPostScaleLeft(A,y);
241: return(0);
242: }
246: PetscErrorCode MatMultTranspose_Shell(Mat A,Vec x,Vec y)
247: {
248: Mat_Shell *shell = (Mat_Shell*)A->data;
250: Vec xx;
253: MatShellPreScaleLeft(A,x,&xx);
254: (*shell->multtranspose)(A,xx,y);
255: MatShellShiftAndScale(A,xx,y);
256: MatShellPostScaleRight(A,y);
257: return(0);
258: }
262: PetscErrorCode MatGetDiagonal_Shell(Mat A,Vec v)
263: {
264: Mat_Shell *shell = (Mat_Shell*)A->data;
268: (*shell->getdiagonal)(A,v);
269: VecScale(v,shell->vscale);
270: if (shell->dshift) {
271: VecPointwiseMult(v,v,shell->dshift);
272: } else {
273: VecShift(v,shell->vshift);
274: }
275: if (shell->left) {VecPointwiseMult(v,v,shell->left);}
276: if (shell->right) {VecPointwiseMult(v,v,shell->right);}
277: return(0);
278: }
282: PetscErrorCode MatShift_Shell(Mat Y,PetscScalar a)
283: {
284: Mat_Shell *shell = (Mat_Shell*)Y->data;
288: if (shell->left || shell->right || shell->dshift) {
289: if (!shell->dshift) {
290: if (!shell->dshift_owned) {VecDuplicate(shell->left ? shell->left : shell->right, &shell->dshift_owned);}
291: shell->dshift = shell->dshift_owned;
292: VecSet(shell->dshift,shell->vshift+a);
293: } else {VecScale(shell->dshift,a);}
294: if (shell->left) {VecPointwiseDivide(shell->dshift,shell->dshift,shell->left);}
295: if (shell->right) {VecPointwiseDivide(shell->dshift,shell->dshift,shell->right);}
296: } else shell->vshift += a;
297: MatShellUseScaledMethods(Y);
298: return(0);
299: }
303: PetscErrorCode MatScale_Shell(Mat Y,PetscScalar a)
304: {
305: Mat_Shell *shell = (Mat_Shell*)Y->data;
309: shell->vscale *= a;
310: if (shell->dshift) {VecScale(shell->dshift,a);}
311: else shell->vshift *= a;
312: MatShellUseScaledMethods(Y);
313: return(0);
314: }
318: static PetscErrorCode MatDiagonalScale_Shell(Mat Y,Vec left,Vec right)
319: {
320: Mat_Shell *shell = (Mat_Shell*)Y->data;
324: if (left) {
325: if (!shell->left_owned) {VecDuplicate(left,&shell->left_owned);}
326: if (shell->left) {VecPointwiseMult(shell->left,shell->left,left);}
327: else {
328: shell->left = shell->left_owned;
329: VecCopy(left,shell->left);
330: }
331: }
332: if (right) {
333: if (!shell->right_owned) {VecDuplicate(right,&shell->right_owned);}
334: if (shell->right) {VecPointwiseMult(shell->right,shell->right,right);}
335: else {
336: shell->right = shell->right_owned;
337: VecCopy(right,shell->right);
338: }
339: }
340: MatShellUseScaledMethods(Y);
341: return(0);
342: }
346: PetscErrorCode MatAssemblyEnd_Shell(Mat Y,MatAssemblyType t)
347: {
348: Mat_Shell *shell = (Mat_Shell*)Y->data;
351: if (t == MAT_FINAL_ASSEMBLY) {
352: shell->vshift = 0.0;
353: shell->vscale = 1.0;
354: shell->dshift = PETSC_NULL;
355: shell->left = PETSC_NULL;
356: shell->right = PETSC_NULL;
357: if (shell->mult) {
358: Y->ops->mult = shell->mult;
359: shell->mult = PETSC_NULL;
360: }
361: if (shell->multtranspose) {
362: Y->ops->multtranspose = shell->multtranspose;
363: shell->multtranspose = PETSC_NULL;
364: }
365: if (shell->getdiagonal) {
366: Y->ops->getdiagonal = shell->getdiagonal;
367: shell->getdiagonal = PETSC_NULL;
368: }
369: shell->usingscaled = PETSC_FALSE;
370: }
371: return(0);
372: }
378: PetscErrorCode MatSetBlockSize_Shell(Mat A,PetscInt bs)
379: {
383: PetscLayoutSetBlockSize(A->rmap,bs);
384: PetscLayoutSetBlockSize(A->cmap,bs);
385: return(0);
386: }
388: static struct _MatOps MatOps_Values = {0,
389: 0,
390: 0,
391: 0,
392: /* 4*/ 0,
393: 0,
394: 0,
395: 0,
396: 0,
397: 0,
398: /*10*/ 0,
399: 0,
400: 0,
401: 0,
402: 0,
403: /*15*/ 0,
404: 0,
405: 0,
406: MatDiagonalScale_Shell,
407: 0,
408: /*20*/ 0,
409: MatAssemblyEnd_Shell,
410: 0,
411: 0,
412: /*24*/ 0,
413: 0,
414: 0,
415: 0,
416: 0,
417: /*29*/ 0,
418: 0,
419: 0,
420: 0,
421: 0,
422: /*34*/ 0,
423: 0,
424: 0,
425: 0,
426: 0,
427: /*39*/ 0,
428: 0,
429: 0,
430: 0,
431: 0,
432: /*44*/ 0,
433: MatScale_Shell,
434: MatShift_Shell,
435: 0,
436: 0,
437: /*49*/ MatSetBlockSize_Shell,
438: 0,
439: 0,
440: 0,
441: 0,
442: /*54*/ 0,
443: 0,
444: 0,
445: 0,
446: 0,
447: /*59*/ 0,
448: MatDestroy_Shell,
449: 0,
450: 0,
451: 0,
452: /*64*/ 0,
453: 0,
454: 0,
455: 0,
456: 0,
457: /*69*/ 0,
458: 0,
459: MatConvert_Shell,
460: 0,
461: 0,
462: /*74*/ 0,
463: 0,
464: 0,
465: 0,
466: 0,
467: /*79*/ 0,
468: 0,
469: 0,
470: 0,
471: 0,
472: /*84*/ 0,
473: 0,
474: 0,
475: 0,
476: 0,
477: /*89*/ 0,
478: 0,
479: 0,
480: 0,
481: 0,
482: /*94*/ 0,
483: 0,
484: 0,
485: 0};
487: /*MC
488: MATSHELL - MATSHELL = "shell" - A matrix type to be used to define your own matrix type -- perhaps matrix free.
490: Level: advanced
492: .seealso: MatCreateShell
493: M*/
498: PetscErrorCode MatCreate_Shell(Mat A)
499: {
500: Mat_Shell *b;
504: PetscMemcpy(A->ops,&MatOps_Values,sizeof(struct _MatOps));
506: PetscNewLog(A,Mat_Shell,&b);
507: A->data = (void*)b;
509: PetscLayoutSetBlockSize(A->rmap,1);
510: PetscLayoutSetBlockSize(A->cmap,1);
511: PetscLayoutSetUp(A->rmap);
512: PetscLayoutSetUp(A->cmap);
514: b->ctx = 0;
515: b->vshift = 0.0;
516: b->vscale = 1.0;
517: b->mult = 0;
518: b->multtranspose = 0;
519: b->getdiagonal = 0;
520: A->assembled = PETSC_TRUE;
521: A->preallocated = PETSC_FALSE;
522: PetscObjectChangeTypeName((PetscObject)A,MATSHELL);
523: return(0);
524: }
529: /*@C
530: MatCreateShell - Creates a new matrix class for use with a user-defined
531: private data storage format.
533: Collective on MPI_Comm
535: Input Parameters:
536: + comm - MPI communicator
537: . m - number of local rows (must be given)
538: . n - number of local columns (must be given)
539: . M - number of global rows (may be PETSC_DETERMINE)
540: . N - number of global columns (may be PETSC_DETERMINE)
541: - ctx - pointer to data needed by the shell matrix routines
543: Output Parameter:
544: . A - the matrix
546: Level: advanced
548: Usage:
550: $ MatCreateShell(comm,m,n,M,N,ctx,&mat);
551: $ MatShellSetOperation(mat,MATOP_MULT,(void(*)(void))mult);
552: $ [ Use matrix for operations that have been set ]
553: $ MatDestroy(mat);
555: Notes:
556: The shell matrix type is intended to provide a simple class to use
557: with KSP (such as, for use with matrix-free methods). You should not
558: use the shell type if you plan to define a complete matrix class.
560: Fortran Notes: The context can only be an integer or a PetscObject
561: unfortunately it cannot be a Fortran array or derived type.
563: PETSc requires that matrices and vectors being used for certain
564: operations are partitioned accordingly. For example, when
565: creating a shell matrix, A, that supports parallel matrix-vector
566: products using MatMult(A,x,y) the user should set the number
567: of local matrix rows to be the number of local elements of the
568: corresponding result vector, y. Note that this is information is
569: required for use of the matrix interface routines, even though
570: the shell matrix may not actually be physically partitioned.
571: For example,
573: $
574: $ Vec x, y
576: $ Mat A
577: $
578: $ VecCreateMPI(comm,PETSC_DECIDE,M,&y);
579: $ VecCreateMPI(comm,PETSC_DECIDE,N,&x);
580: $ VecGetLocalSize(y,&m);
581: $ VecGetLocalSize(x,&n);
582: $ MatCreateShell(comm,m,n,M,N,ctx,&A);
583: $ MatShellSetOperation(mat,MATOP_MULT,(void(*)(void))mult);
584: $ MatMult(A,x,y);
585: $ MatDestroy(A);
586: $ VecDestroy(y); VecDestroy(x);
587: $
589: .keywords: matrix, shell, create
591: .seealso: MatShellSetOperation(), MatHasOperation(), MatShellGetContext(), MatShellSetContext()
592: @*/
593: PetscErrorCode MatCreateShell(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,void *ctx,Mat *A)
594: {
598: MatCreate(comm,A);
599: MatSetSizes(*A,m,n,M,N);
600:
601: MatSetType(*A,MATSHELL);
602: MatShellSetContext(*A,ctx);
603: return(0);
604: }
608: /*@
609: MatShellSetContext - sets the context for a shell matrix
611: Logically Collective on Mat
613: Input Parameters:
614: + mat - the shell matrix
615: - ctx - the context
617: Level: advanced
619: Fortran Notes: The context can only be an integer or a PetscObject
620: unfortunately it cannot be a Fortran array or derived type.
622: .seealso: MatCreateShell(), MatShellGetContext(), MatShellGetOperation()
623: @*/
624: PetscErrorCode MatShellSetContext(Mat mat,void *ctx)
625: {
626: Mat_Shell *shell = (Mat_Shell*)mat->data;
628: PetscBool flg;
632: PetscTypeCompare((PetscObject)mat,MATSHELL,&flg);
633: if (flg) {
634: shell->ctx = ctx;
635: } else SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_SUP,"Cannot attach context to non-shell matrix");
636: return(0);
637: }
641: /*@C
642: MatShellSetOperation - Allows user to set a matrix operation for
643: a shell matrix.
645: Logically Collective on Mat
647: Input Parameters:
648: + mat - the shell matrix
649: . op - the name of the operation
650: - f - the function that provides the operation.
652: Level: advanced
654: Usage:
656: $ MatCreateShell(comm,m,n,M,N,ctx,&A);
657: $ MatShellSetOperation(A,MATOP_MULT,(void(*)(void))usermult);
659: Notes:
660: See the file include/petscmat.h for a complete list of matrix
661: operations, which all have the form MATOP_<OPERATION>, where
662: <OPERATION> is the name (in all capital letters) of the
663: user interface routine (e.g., MatMult() -> MATOP_MULT).
665: All user-provided functions should have the same calling
666: sequence as the usual matrix interface routines, since they
667: are intended to be accessed via the usual matrix interface
668: routines, e.g.,
669: $ MatMult(Mat,Vec,Vec) -> usermult(Mat,Vec,Vec)
671: In particular each function MUST return an error code of 0 on success and
672: nonzero on failure.
674: Within each user-defined routine, the user should call
675: MatShellGetContext() to obtain the user-defined context that was
676: set by MatCreateShell().
678: Fortran Notes: For MatGetVecs() the user code should check if the input left or right matrix is -1 and in that case not
679: generate a matrix. See src/mat/examples/tests/ex120f.F
681: .keywords: matrix, shell, set, operation
683: .seealso: MatCreateShell(), MatShellGetContext(), MatShellGetOperation(), MatShellSetContext()
684: @*/
685: PetscErrorCode MatShellSetOperation(Mat mat,MatOperation op,void (*f)(void))
686: {
688: PetscBool flg;
692: if (op == MATOP_DESTROY) {
693: PetscTypeCompare((PetscObject)mat,MATSHELL,&flg);
694: if (flg) {
695: Mat_Shell *shell = (Mat_Shell*)mat->data;
696: shell->destroy = (PetscErrorCode (*)(Mat)) f;
697: } else mat->ops->destroy = (PetscErrorCode (*)(Mat)) f;
698: }
699: else if (op == MATOP_VIEW) mat->ops->view = (PetscErrorCode (*)(Mat,PetscViewer)) f;
700: else (((void(**)(void))mat->ops)[op]) = f;
702: return(0);
703: }
707: /*@C
708: MatShellGetOperation - Gets a matrix function for a shell matrix.
710: Not Collective
712: Input Parameters:
713: + mat - the shell matrix
714: - op - the name of the operation
716: Output Parameter:
717: . f - the function that provides the operation.
719: Level: advanced
721: Notes:
722: See the file include/petscmat.h for a complete list of matrix
723: operations, which all have the form MATOP_<OPERATION>, where
724: <OPERATION> is the name (in all capital letters) of the
725: user interface routine (e.g., MatMult() -> MATOP_MULT).
727: All user-provided functions have the same calling
728: sequence as the usual matrix interface routines, since they
729: are intended to be accessed via the usual matrix interface
730: routines, e.g.,
731: $ MatMult(Mat,Vec,Vec) -> usermult(Mat,Vec,Vec)
733: Within each user-defined routine, the user should call
734: MatShellGetContext() to obtain the user-defined context that was
735: set by MatCreateShell().
737: .keywords: matrix, shell, set, operation
739: .seealso: MatCreateShell(), MatShellGetContext(), MatShellSetOperation(), MatShellSetContext()
740: @*/
741: PetscErrorCode MatShellGetOperation(Mat mat,MatOperation op,void(**f)(void))
742: {
744: PetscBool flg;
748: if (op == MATOP_DESTROY) {
749: PetscTypeCompare((PetscObject)mat,MATSHELL,&flg);
750: if (flg) {
751: Mat_Shell *shell = (Mat_Shell*)mat->data;
752: *f = (void(*)(void))shell->destroy;
753: } else {
754: *f = (void(*)(void))mat->ops->destroy;
755: }
756: } else if (op == MATOP_VIEW) {
757: *f = (void(*)(void))mat->ops->view;
758: } else {
759: *f = (((void(**)(void))mat->ops)[op]);
760: }
762: return(0);
763: }