1: /*
2: Implements the ST class for preconditioned eigenvalue methods.
4: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
5: SLEPc - Scalable Library for Eigenvalue Problem Computations
6: Copyright (c) 2002-2016, Universitat Politecnica de Valencia, Spain
8: This file is part of SLEPc.
10: SLEPc is free software: you can redistribute it and/or modify it under the
11: terms of version 3 of the GNU Lesser General Public License as published by
12: the Free Software Foundation.
14: SLEPc is distributed in the hope that it will be useful, but WITHOUT ANY
15: WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
16: FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
17: more details.
19: You should have received a copy of the GNU Lesser General Public License
20: along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
21: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
22: */
24: #include <slepc/private/stimpl.h> /*I "slepcst.h" I*/
26: typedef struct {
27: PetscBool setmat;
28: } ST_PRECOND;
32: PetscErrorCode STSetFromOptions_Precond(PetscOptionItems *PetscOptionsObject,ST st) 33: {
35: PC pc;
36: PCType pctype;
37: Mat P;
38: PetscBool t0,t1;
39: KSP ksp;
42: STGetKSP(st,&ksp);
43: KSPGetPC(ksp,&pc);
44: PetscObjectGetType((PetscObject)pc,&pctype);
45: STPrecondGetMatForPC(st,&P);
46: if (!pctype && st->A && st->A[0]) {
47: if (P || st->shift_matrix == ST_MATMODE_SHELL) {
48: PCSetType(pc,PCJACOBI);
49: } else {
50: MatHasOperation(st->A[0],MATOP_DUPLICATE,&t0);
51: if (st->nmat>1) {
52: MatHasOperation(st->A[0],MATOP_AXPY,&t1);
53: } else t1 = PETSC_TRUE;
54: PCSetType(pc,(t0 && t1)?PCJACOBI:PCNONE);
55: }
56: }
57: return(0);
58: }
62: PetscErrorCode STSetUp_Precond(ST st) 63: {
64: Mat P;
65: PC pc;
66: PetscBool t0,setmat,destroyP=PETSC_FALSE,builtP;
70: /* if the user did not set the shift, use the target value */
71: if (!st->sigma_set) st->sigma = st->defsigma;
73: /* If either pc is none and no matrix has to be set, or pc is shell , exit */
74: if (!st->ksp) { STGetKSP(st,&st->ksp); }
75: KSPGetPC(st->ksp,&pc);
76: PetscObjectTypeCompare((PetscObject)pc,PCSHELL,&t0);
77: if (t0) return(0);
78: PetscObjectTypeCompare((PetscObject)pc,PCNONE,&t0);
79: STPrecondGetKSPHasMat(st,&setmat);
80: if (t0 && !setmat) return(0);
82: /* Check if a user matrix is set */
83: STPrecondGetMatForPC(st,&P);
85: /* If not, create A - shift*B */
86: if (P) {
87: builtP = PETSC_FALSE;
88: destroyP = PETSC_TRUE;
89: PetscObjectReference((PetscObject)P);
90: } else {
91: builtP = PETSC_TRUE;
93: if (!(PetscAbsScalar(st->sigma) < PETSC_MAX_REAL) && st->nmat>1) {
94: P = st->A[1];
95: destroyP = PETSC_FALSE;
96: } else if (st->sigma == 0.0) {
97: P = st->A[0];
98: destroyP = PETSC_FALSE;
99: } else if (PetscAbsScalar(st->sigma) < PETSC_MAX_REAL && st->shift_matrix != ST_MATMODE_SHELL) {
100: if (st->shift_matrix == ST_MATMODE_INPLACE) {
101: P = st->A[0];
102: destroyP = PETSC_FALSE;
103: } else {
104: MatDuplicate(st->A[0],MAT_COPY_VALUES,&P);
105: destroyP = PETSC_TRUE;
106: }
107: if (st->nmat>1) {
108: MatAXPY(P,-st->sigma,st->A[1],st->str);
109: } else {
110: MatShift(P,-st->sigma);
111: }
112: /* TODO: in case of ST_MATMODE_INPLACE should keep the Hermitian flag of st->A and restore at the end */
113: STMatSetHermitian(st,P);
114: } else builtP = PETSC_FALSE;
115: }
117: /* If P was not possible to obtain, set pc to PCNONE */
118: if (!P) {
119: PCSetType(pc,PCNONE);
121: /* If some matrix has to be set to ksp, a shell matrix is created */
122: if (setmat) {
123: STMatShellCreate(st,-st->sigma,0,NULL,NULL,&P);
124: STMatSetHermitian(st,P);
125: destroyP = PETSC_TRUE;
126: }
127: }
129: KSPSetOperators(st->ksp,setmat?P:NULL,P);
131: if (destroyP) {
132: MatDestroy(&P);
133: } else if (st->shift_matrix == ST_MATMODE_INPLACE && builtP) {
134: if (st->sigma != 0.0 && PetscAbsScalar(st->sigma) < PETSC_MAX_REAL) {
135: if (st->nmat>1) {
136: MatAXPY(st->A[0],st->sigma,st->A[1],st->str);
137: } else {
138: MatShift(st->A[0],st->sigma);
139: }
140: }
141: }
142: return(0);
143: }
147: PetscErrorCode STSetShift_Precond(ST st,PetscScalar newshift)148: {
152: /* Nothing to be done if STSetUp has not been called yet */
153: if (!st->state) return(0);
154: st->sigma = newshift;
155: if (st->shift_matrix != ST_MATMODE_SHELL) {
156: STSetUp_Precond(st);
157: }
158: return(0);
159: }
163: static PetscErrorCode STPrecondGetMatForPC_Precond(ST st,Mat *mat)164: {
166: PC pc;
167: PetscBool flag;
170: if (!st->ksp) { STGetKSP(st,&st->ksp); }
171: KSPGetPC(st->ksp,&pc);
172: PCGetOperatorsSet(pc,NULL,&flag);
173: if (flag) {
174: PCGetOperators(pc,NULL,mat);
175: } else *mat = NULL;
176: return(0);
177: }
181: /*@
182: STPrecondGetMatForPC - Returns the matrix previously set by STPrecondSetMatForPC().
184: Not Collective, but the Mat is shared by all processors that share the ST186: Input Parameter:
187: . st - the spectral transformation context
189: Output Parameter:
190: . mat - the matrix that will be used in constructing the preconditioner or
191: NULL if no matrix was set by STPrecondSetMatForPC().
193: Level: advanced
195: .seealso: STPrecondSetMatForPC()
196: @*/
197: PetscErrorCode STPrecondGetMatForPC(ST st,Mat *mat)198: {
204: PetscUseMethod(st,"STPrecondGetMatForPC_C",(ST,Mat*),(st,mat));
205: return(0);
206: }
210: static PetscErrorCode STPrecondSetMatForPC_Precond(ST st,Mat mat)211: {
212: PC pc;
213: Mat A;
214: PetscBool flag;
218: if (!st->ksp) { STGetKSP(st,&st->ksp); }
219: KSPGetPC(st->ksp,&pc);
220: /* Yes, all these lines are needed to safely set mat as the preconditioner
221: matrix in pc */
222: PCGetOperatorsSet(pc,&flag,NULL);
223: if (flag) {
224: PCGetOperators(pc,&A,NULL);
225: PetscObjectReference((PetscObject)A);
226: } else A = NULL;
227: PetscObjectReference((PetscObject)mat);
228: PCSetOperators(pc,A,mat);
229: MatDestroy(&A);
230: MatDestroy(&mat);
231: STPrecondSetKSPHasMat(st,PETSC_TRUE);
232: return(0);
233: }
237: /*@
238: STPrecondSetMatForPC - Sets the matrix that must be used to build the preconditioner.
240: Logically Collective on ST and Mat
242: Input Parameter:
243: + st - the spectral transformation context
244: - mat - the matrix that will be used in constructing the preconditioner
246: Level: advanced
248: Notes:
249: This matrix will be passed to the KSP object (via KSPSetOperators) as
250: the matrix to be used when constructing the preconditioner.
251: If no matrix is set or mat is set to NULL, A - sigma*B will
252: be used to build the preconditioner, being sigma the value set by STSetShift().
254: .seealso: STPrecondSetMatForPC(), STSetShift()
255: @*/
256: PetscErrorCode STPrecondSetMatForPC(ST st,Mat mat)257: {
264: PetscTryMethod(st,"STPrecondSetMatForPC_C",(ST,Mat),(st,mat));
265: return(0);
266: }
270: static PetscErrorCode STPrecondSetKSPHasMat_Precond(ST st,PetscBool setmat)271: {
272: ST_PRECOND *data = (ST_PRECOND*)st->data;
275: data->setmat = setmat;
276: return(0);
277: }
281: /*@
282: STPrecondSetKSPHasMat - Sets a flag indicating that during STSetUp the coefficient
283: matrix of the KSP linear system (A) must be set to be the same matrix as the
284: preconditioner (P).
286: Collective on ST288: Input Parameter:
289: + st - the spectral transformation context
290: - setmat - the flag
292: Notes:
293: In most cases, the preconditioner matrix is used only in the PC object, but
294: in external solvers this matrix must be provided also as the A-matrix in
295: the KSP object.
297: Level: developer
299: .seealso: STPrecondGetKSPHasMat(), STSetShift()
300: @*/
301: PetscErrorCode STPrecondSetKSPHasMat(ST st,PetscBool setmat)302: {
308: PetscTryMethod(st,"STPrecondSetKSPHasMat_C",(ST,PetscBool),(st,setmat));
309: return(0);
310: }
314: static PetscErrorCode STPrecondGetKSPHasMat_Precond(ST st,PetscBool *setmat)315: {
316: ST_PRECOND *data = (ST_PRECOND*)st->data;
319: *setmat = data->setmat;
320: return(0);
321: }
325: /*@
326: STPrecondGetKSPHasMat - Returns the flag indicating if the coefficient
327: matrix of the KSP linear system (A) is set to be the same matrix as the
328: preconditioner (P).
330: Not Collective
332: Input Parameter:
333: . st - the spectral transformation context
335: Output Parameter:
336: . setmat - the flag
338: Level: developer
340: .seealso: STPrecondSetKSPHasMat(), STSetShift()
341: @*/
342: PetscErrorCode STPrecondGetKSPHasMat(ST st,PetscBool *setmat)343: {
349: PetscUseMethod(st,"STPrecondGetKSPHasMat_C",(ST,PetscBool*),(st,setmat));
350: return(0);
351: }
355: PetscErrorCode STDestroy_Precond(ST st)356: {
360: PetscFree(st->data);
361: PetscObjectComposeFunction((PetscObject)st,"STPrecondGetMatForPC_C",NULL);
362: PetscObjectComposeFunction((PetscObject)st,"STPrecondSetMatForPC_C",NULL);
363: PetscObjectComposeFunction((PetscObject)st,"STPrecondGetKSPHasMat_C",NULL);
364: PetscObjectComposeFunction((PetscObject)st,"STPrecondSetKSPHasMat_C",NULL);
365: return(0);
366: }
370: PETSC_EXTERN PetscErrorCode STCreate_Precond(ST st)371: {
373: ST_PRECOND *ctx;
376: PetscNewLog(st,&ctx);
377: st->data = (void*)ctx;
379: st->ops->getbilinearform = STGetBilinearForm_Default;
380: st->ops->setup = STSetUp_Precond;
381: st->ops->setshift = STSetShift_Precond;
382: st->ops->destroy = STDestroy_Precond;
383: st->ops->setfromoptions = STSetFromOptions_Precond;
385: PetscObjectComposeFunction((PetscObject)st,"STPrecondGetMatForPC_C",STPrecondGetMatForPC_Precond);
386: PetscObjectComposeFunction((PetscObject)st,"STPrecondSetMatForPC_C",STPrecondSetMatForPC_Precond);
387: PetscObjectComposeFunction((PetscObject)st,"STPrecondGetKSPHasMat_C",STPrecondGetKSPHasMat_Precond);
388: PetscObjectComposeFunction((PetscObject)st,"STPrecondSetKSPHasMat_C",STPrecondSetKSPHasMat_Precond);
390: STPrecondSetKSPHasMat_Precond(st,PETSC_TRUE);
391: return(0);
392: }