Actual source code: mgadapt.c
1: #include <petsc/private/pcmgimpl.h>
2: #include <petscdm.h>
4: static PetscErrorCode xfunc(PetscInt dim, PetscReal time, const PetscReal coords[], PetscInt Nc, PetscScalar *u, void *ctx)
5: {
6: PetscInt k = *((PetscInt *)ctx), c;
8: for (c = 0; c < Nc; ++c) u[c] = PetscPowRealInt(coords[0], k);
9: return 0;
10: }
11: static PetscErrorCode yfunc(PetscInt dim, PetscReal time, const PetscReal coords[], PetscInt Nc, PetscScalar *u, void *ctx)
12: {
13: PetscInt k = *((PetscInt *)ctx), c;
15: for (c = 0; c < Nc; ++c) u[c] = PetscPowRealInt(coords[1], k);
16: return 0;
17: }
18: static PetscErrorCode zfunc(PetscInt dim, PetscReal time, const PetscReal coords[], PetscInt Nc, PetscScalar *u, void *ctx)
19: {
20: PetscInt k = *((PetscInt *)ctx), c;
22: for (c = 0; c < Nc; ++c) u[c] = PetscPowRealInt(coords[2], k);
23: return 0;
24: }
25: static PetscErrorCode xsin(PetscInt dim, PetscReal time, const PetscReal coords[], PetscInt Nc, PetscScalar *u, void *ctx)
26: {
27: PetscInt k = *((PetscInt *)ctx), c;
29: for (c = 0; c < Nc; ++c) u[c] = PetscSinReal(PETSC_PI * (k + 1) * coords[0]);
30: return 0;
31: }
32: static PetscErrorCode ysin(PetscInt dim, PetscReal time, const PetscReal coords[], PetscInt Nc, PetscScalar *u, void *ctx)
33: {
34: PetscInt k = *((PetscInt *)ctx), c;
36: for (c = 0; c < Nc; ++c) u[c] = PetscSinReal(PETSC_PI * (k + 1) * coords[1]);
37: return 0;
38: }
39: static PetscErrorCode zsin(PetscInt dim, PetscReal time, const PetscReal coords[], PetscInt Nc, PetscScalar *u, void *ctx)
40: {
41: PetscInt k = *((PetscInt *)ctx), c;
43: for (c = 0; c < Nc; ++c) u[c] = PetscSinReal(PETSC_PI * (k + 1) * coords[2]);
44: return 0;
45: }
47: PetscErrorCode DMSetBasisFunction_Internal(PetscInt Nf, PetscBool usePoly, PetscInt dir, PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar *, void *))
48: {
49: PetscInt f;
52: for (f = 0; f < Nf; ++f) {
53: if (usePoly) {
54: switch (dir) {
55: case 0:
56: funcs[f] = xfunc;
57: break;
58: case 1:
59: funcs[f] = yfunc;
60: break;
61: case 2:
62: funcs[f] = zfunc;
63: break;
64: default:
65: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "No function for direction %" PetscInt_FMT, dir);
66: }
67: } else {
68: switch (dir) {
69: case 0:
70: funcs[f] = xsin;
71: break;
72: case 1:
73: funcs[f] = ysin;
74: break;
75: case 2:
76: funcs[f] = zsin;
77: break;
78: default:
79: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "No function for direction %" PetscInt_FMT, dir);
80: }
81: }
82: }
83: return 0;
84: }
86: static PetscErrorCode PCMGCreateCoarseSpaceDefault_Private(PC pc, PetscInt level, PCMGCoarseSpaceType cstype, DM dm, KSP ksp, PetscInt Nc, Mat initialGuess, Mat *coarseSpace)
87: {
88: PetscBool poly = cstype == PCMG_ADAPT_POLYNOMIAL ? PETSC_TRUE : PETSC_FALSE;
89: PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar *, void *);
90: void **ctxs;
91: PetscInt dim, d, Nf, f, k, m, M;
92: Vec tmp;
94: Nc = Nc < 0 ? 6 : Nc;
95: DMGetCoordinateDim(dm, &dim);
96: DMGetNumFields(dm, &Nf);
98: PetscMalloc2(Nf, &funcs, Nf, &ctxs);
99: DMGetGlobalVector(dm, &tmp);
100: VecGetSize(tmp, &M);
101: VecGetLocalSize(tmp, &m);
102: MatCreateDense(PetscObjectComm((PetscObject)pc), m, PETSC_DECIDE, M, Nc, NULL, coarseSpace);
103: DMRestoreGlobalVector(dm, &tmp);
104: for (k = 0; k < Nc / dim; ++k) {
105: for (f = 0; f < Nf; ++f) ctxs[f] = &k;
106: for (d = 0; d < dim; ++d) {
107: MatDenseGetColumnVecWrite(*coarseSpace, k * dim + d, &tmp);
108: DMSetBasisFunction_Internal(Nf, poly, d, funcs);
109: DMProjectFunction(dm, 0.0, funcs, ctxs, INSERT_ALL_VALUES, tmp);
110: MatDenseRestoreColumnVecWrite(*coarseSpace, k * dim + d, &tmp);
111: }
112: }
113: PetscFree2(funcs, ctxs);
114: return 0;
115: }
117: static PetscErrorCode PCMGCreateCoarseSpace_Polynomial(PC pc, PetscInt level, DM dm, KSP ksp, PetscInt Nc, Mat initialGuess, Mat *coarseSpace)
118: {
119: PCMGCreateCoarseSpaceDefault_Private(pc, level, PCMG_ADAPT_POLYNOMIAL, dm, ksp, Nc, initialGuess, coarseSpace);
120: return 0;
121: }
123: PetscErrorCode PCMGCreateCoarseSpace_Harmonic(PC pc, PetscInt level, DM dm, KSP ksp, PetscInt Nc, Mat initialGuess, Mat *coarseSpace)
124: {
125: PCMGCreateCoarseSpaceDefault_Private(pc, level, PCMG_ADAPT_HARMONIC, dm, ksp, Nc, initialGuess, coarseSpace);
126: return 0;
127: }
129: /*
130: PCMGComputeCoarseSpace_Internal - Compute vectors on level l that must be accurately interpolated.
132: Input Parameters:
133: + pc - The PCMG
134: . l - The level
135: . Nc - The number of vectors requested
136: - cspace - The initial guess for the space, or NULL
138: Output Parameter:
139: . space - The space which must be accurately interpolated.
141: Level: developer
143: Note: This space is normally used to adapt the interpolator. If Nc is negative, an adaptive choice can be made.
145: .seealso: `PCMGAdaptInterpolator_Private()`
146: */
147: PetscErrorCode PCMGComputeCoarseSpace_Internal(PC pc, PetscInt l, PCMGCoarseSpaceType cstype, PetscInt Nc, Mat cspace, Mat *space)
148: {
149: PetscErrorCode (*coarseConstructor)(PC, PetscInt, DM, KSP, PetscInt, Mat, Mat *) = NULL;
150: DM dm;
151: KSP smooth;
153: *space = NULL;
154: switch (cstype) {
155: case PCMG_ADAPT_POLYNOMIAL:
156: coarseConstructor = &PCMGCreateCoarseSpace_Polynomial;
157: break;
158: case PCMG_ADAPT_HARMONIC:
159: coarseConstructor = &PCMGCreateCoarseSpace_Harmonic;
160: break;
161: case PCMG_ADAPT_EIGENVECTOR:
162: Nc = Nc < 0 ? 6 : Nc;
163: if (l > 0) PCMGGetCoarseSpaceConstructor("BAMG_MEV", &coarseConstructor);
164: else PCMGGetCoarseSpaceConstructor("BAMG_EV", &coarseConstructor);
165: break;
166: case PCMG_ADAPT_GENERALIZED_EIGENVECTOR:
167: Nc = Nc < 0 ? 6 : Nc;
168: if (l > 0) PCMGGetCoarseSpaceConstructor("BAMG_MGEV", &coarseConstructor);
169: else PCMGGetCoarseSpaceConstructor("BAMG_GEV", &coarseConstructor);
170: break;
171: case PCMG_ADAPT_GDSW:
172: coarseConstructor = &PCMGGDSWCreateCoarseSpace_Private;
173: break;
174: case PCMG_ADAPT_NONE:
175: break;
176: default:
177: SETERRQ(PetscObjectComm((PetscObject)pc), PETSC_ERR_SUP, "Cannot handle coarse space type %d", cstype);
178: }
179: if (coarseConstructor) {
180: PCMGGetSmoother(pc, l, &smooth);
181: KSPGetDM(smooth, &dm);
182: (*coarseConstructor)(pc, l, dm, smooth, Nc, cspace, space);
183: }
184: return 0;
185: }
187: /*
188: PCMGAdaptInterpolator_Internal - Adapt interpolator from level l-1 to level l
190: Input Parameters:
191: + pc - The PCMG
192: . l - The level l
193: . csmooth - The (coarse) smoother for level l-1
194: . fsmooth - The (fine) smoother for level l
195: . cspace - The (coarse) vectors in the subspace for level l-1
196: - fspace - The (fine) vectors in the subspace for level l
198: Level: developer
200: Note: This routine resets the interpolation and restriction for level l.
202: .seealso: `PCMGComputeCoarseSpace_Private()`
203: */
204: PetscErrorCode PCMGAdaptInterpolator_Internal(PC pc, PetscInt l, KSP csmooth, KSP fsmooth, Mat cspace, Mat fspace)
205: {
206: PC_MG *mg = (PC_MG *)pc->data;
207: DM dm, cdm;
208: Mat Interp, InterpAdapt;
210: /* There is no interpolator for the coarse level */
211: if (!l) return 0;
212: KSPGetDM(csmooth, &cdm);
213: KSPGetDM(fsmooth, &dm);
214: PCMGGetInterpolation(pc, l, &Interp);
215: if (Interp == fspace && !cspace) return 0;
216: DMAdaptInterpolator(cdm, dm, Interp, fsmooth, fspace, cspace, &InterpAdapt, pc);
217: if (mg->mespMonitor) DMCheckInterpolator(dm, InterpAdapt, cspace, fspace, 0.5 /* PETSC_SMALL */);
218: PCMGSetInterpolation(pc, l, InterpAdapt);
219: PCMGSetRestriction(pc, l, InterpAdapt); /* MATT: Remove????? */
220: MatDestroy(&InterpAdapt);
221: return 0;
222: }
224: /*
225: PCMGRecomputeLevelOperators_Internal - Recomputes Galerkin coarse operator when interpolation is adapted
227: Note: This routine recomputes the Galerkin triple product for the operator on level l.
228: */
229: PetscErrorCode PCMGRecomputeLevelOperators_Internal(PC pc, PetscInt l)
230: {
231: Mat fA, fB; /* The system and preconditioning operators on level l+1 */
232: Mat A, B; /* The system and preconditioning operators on level l */
233: Mat Interp, Restrc; /* The interpolation operator from level l to l+1, and restriction operator from level l+1 to l */
234: KSP smooth, fsmooth; /* The smoothers on levels l and l+1 */
235: PCMGGalerkinType galerkin; /* The Galerkin projection flag */
236: MatReuse reuse = MAT_REUSE_MATRIX; /* The matrices are always assumed to be present already */
237: PetscBool doA = PETSC_FALSE; /* Updates the system operator */
238: PetscBool doB = PETSC_FALSE; /* Updates the preconditioning operator (A == B, then update B) */
239: PetscInt n; /* The number of multigrid levels */
241: PCMGGetGalerkin(pc, &galerkin);
242: if (galerkin >= PC_MG_GALERKIN_NONE) return 0;
243: PCMGGetLevels(pc, &n);
244: /* Do not recompute operator for the finest grid */
245: if (l == n - 1) return 0;
246: PCMGGetSmoother(pc, l, &smooth);
247: KSPGetOperators(smooth, &A, &B);
248: PCMGGetSmoother(pc, l + 1, &fsmooth);
249: KSPGetOperators(fsmooth, &fA, &fB);
250: PCMGGetInterpolation(pc, l + 1, &Interp);
251: PCMGGetRestriction(pc, l + 1, &Restrc);
252: if ((galerkin == PC_MG_GALERKIN_PMAT) || (galerkin == PC_MG_GALERKIN_BOTH)) doB = PETSC_TRUE;
253: if ((galerkin == PC_MG_GALERKIN_MAT) || ((galerkin == PC_MG_GALERKIN_BOTH) && (fA != fB))) doA = PETSC_TRUE;
254: if (doA) MatGalerkin(Restrc, fA, Interp, reuse, 1.0, &A);
255: if (doB) MatGalerkin(Restrc, fB, Interp, reuse, 1.0, &B);
256: return 0;
257: }