xref: /petsc/src/ts/utils/tsconvest.c (revision bcd3bd92eda2d5998e2f14c4bbfb33bd936bdc3e)
1 #include <petscconvest.h> /*I "petscconvest.h" I*/
2 #include <petscts.h>
3 #include <petscdmplex.h>
4 
5 #include <petsc/private/petscconvestimpl.h>
6 
7 static PetscErrorCode PetscConvEstSetTS_Private(PetscConvEst ce, PetscObject solver)
8 {
9   PetscClassId id;
10 
11   PetscFunctionBegin;
12   PetscCall(PetscObjectGetClassId(ce->solver, &id));
13   PetscCheck(id == TS_CLASSID, PetscObjectComm((PetscObject)ce), PETSC_ERR_ARG_WRONG, "Solver was not a TS");
14   PetscCall(TSGetDM((TS)ce->solver, &ce->idm));
15   PetscFunctionReturn(PETSC_SUCCESS);
16 }
17 
18 static PetscErrorCode PetscConvEstInitGuessTS_Private(PetscConvEst ce, PetscInt r, DM dm, Vec u)
19 {
20   PetscFunctionBegin;
21   PetscCall(TSComputeInitialCondition((TS)ce->solver, u));
22   PetscFunctionReturn(PETSC_SUCCESS);
23 }
24 
25 static PetscErrorCode PetscConvEstComputeErrorTS_Private(PetscConvEst ce, PetscInt r, DM dm, Vec u, PetscReal errors[])
26 {
27   TS ts = (TS)ce->solver;
28   PetscErrorCode (*exactError)(TS, Vec, Vec);
29 
30   PetscFunctionBegin;
31   PetscCall(TSGetComputeExactError(ts, &exactError));
32   if (exactError) {
33     Vec      e;
34     PetscInt f;
35 
36     PetscCall(VecDuplicate(u, &e));
37     PetscCall(TSComputeExactError(ts, u, e));
38     PetscCall(VecNorm(e, NORM_2, errors));
39     for (f = 1; f < ce->Nf; ++f) errors[f] = errors[0];
40     PetscCall(VecDestroy(&e));
41   } else {
42     PetscReal t;
43 
44     PetscCall(TSGetSolveTime(ts, &t));
45     PetscCall(DMComputeL2FieldDiff(dm, t, ce->exactSol, ce->ctxs, u, errors));
46   }
47   PetscFunctionReturn(PETSC_SUCCESS);
48 }
49 
50 static PetscErrorCode PetscConvEstGetConvRateTS_Temporal_Private(PetscConvEst ce, PetscReal alpha[])
51 {
52   TS         ts = (TS)ce->solver;
53   Vec        u, u0;
54   PetscReal *dt, *x, *y, slope, intercept;
55   PetscInt   Ns, oNs, Nf = ce->Nf, f, Nr = ce->Nr, r;
56 
57   PetscFunctionBegin;
58   PetscCall(PetscMalloc1(Nr + 1, &dt));
59   PetscCall(TSGetTimeStep(ts, &dt[0]));
60   PetscCall(TSGetMaxSteps(ts, &oNs));
61   PetscCall(TSGetSolution(ts, &u0));
62   PetscCall(PetscObjectReference((PetscObject)u0));
63   Ns = oNs;
64   for (r = 0; r <= Nr; ++r) {
65     if (r > 0) {
66       dt[r] = dt[r - 1] / ce->r;
67       Ns    = PetscCeilReal(Ns * ce->r);
68     }
69     PetscCall(TSSetTime(ts, 0.0));
70     PetscCall(TSSetStepNumber(ts, 0));
71     PetscCall(TSSetTimeStep(ts, dt[r]));
72     PetscCall(TSSetMaxSteps(ts, Ns));
73     PetscCall(TSGetSolution(ts, &u));
74     PetscCall(PetscConvEstComputeInitialGuess(ce, r, NULL, u));
75     PetscCall(TSSolve(ts, NULL));
76     PetscCall(TSGetSolution(ts, &u));
77     PetscCall(PetscLogEventBegin(ce->event, ce, 0, 0, 0));
78     PetscCall(PetscConvEstComputeError(ce, r, ce->idm, u, &ce->errors[r * Nf]));
79     PetscCall(PetscLogEventEnd(ce->event, ce, 0, 0, 0));
80     for (f = 0; f < Nf; ++f) {
81       ce->dofs[r * Nf + f] = 1.0 / dt[r];
82       PetscCall(PetscLogEventSetDof(ce->event, f, ce->dofs[r * Nf + f]));
83       PetscCall(PetscLogEventSetError(ce->event, f, ce->errors[r * Nf + f]));
84     }
85     /* Monitor */
86     PetscCall(PetscConvEstMonitorDefault(ce, r));
87   }
88   /* Fit convergence rate */
89   if (Nr) {
90     PetscCall(PetscMalloc2(Nr + 1, &x, Nr + 1, &y));
91     for (f = 0; f < Nf; ++f) {
92       for (r = 0; r <= Nr; ++r) {
93         x[r] = PetscLog10Real(dt[r]);
94         y[r] = PetscLog10Real(ce->errors[r * Nf + f]);
95       }
96       PetscCall(PetscLinearRegression(Nr + 1, x, y, &slope, &intercept));
97       /* Since lg err = s lg dt + b */
98       alpha[f] = slope;
99     }
100     PetscCall(PetscFree2(x, y));
101   }
102   /* Reset solver */
103   PetscCall(TSReset(ts));
104   PetscCall(TSSetConvergedReason(ts, TS_CONVERGED_ITERATING));
105   PetscCall(TSSetTime(ts, 0.0));
106   PetscCall(TSSetStepNumber(ts, 0));
107   PetscCall(TSSetTimeStep(ts, dt[0]));
108   PetscCall(TSSetMaxSteps(ts, oNs));
109   PetscCall(TSSetSolution(ts, u0));
110   PetscCall(PetscConvEstComputeInitialGuess(ce, 0, NULL, u0));
111   PetscCall(VecDestroy(&u0));
112   PetscCall(PetscFree(dt));
113   PetscFunctionReturn(PETSC_SUCCESS);
114 }
115 
116 static PetscErrorCode PetscConvEstGetConvRateTS_Spatial_Private(PetscConvEst ce, PetscReal alpha[])
117 {
118   TS          ts = (TS)ce->solver;
119   Vec         uInitial;
120   DM         *dm;
121   PetscObject disc;
122   PetscReal  *x, *y, slope, intercept;
123   PetscInt    Nr = ce->Nr, r, Nf = ce->Nf, f, dim, oldlevel, oldnlev;
124   PetscErrorCode (*ifunc)(DM, PetscReal, Vec, Vec, Vec, void *);
125   PetscErrorCode (*ijac)(DM, PetscReal, Vec, Vec, PetscReal, Mat, Mat, void *);
126   PetscErrorCode (*rhsfunc)(DM, PetscReal, Vec, Vec, void *);
127   void *fctx, *jctx, *rctx;
128   void *ctx;
129 
130   PetscFunctionBegin;
131   PetscCheck(ce->r == 2.0, PetscObjectComm((PetscObject)ce), PETSC_ERR_SUP, "Only refinement factor 2 is currently supported (not %g)", (double)ce->r);
132   PetscCall(DMGetDimension(ce->idm, &dim));
133   PetscCall(DMGetApplicationContext(ce->idm, &ctx));
134   PetscCall(DMPlexSetRefinementUniform(ce->idm, PETSC_TRUE));
135   PetscCall(DMGetRefineLevel(ce->idm, &oldlevel));
136   PetscCall(PetscMalloc1((Nr + 1), &dm));
137   PetscCall(TSGetSolution(ts, &uInitial));
138   PetscCall(PetscObjectReference((PetscObject)uInitial));
139 
140   /* Loop over meshes */
141   dm[0] = ce->idm;
142   for (r = 0; r <= Nr; ++r) {
143     Vec u;
144 #if defined(PETSC_USE_LOG)
145     PetscLogStage stage;
146 #endif
147     char        stageName[PETSC_MAX_PATH_LEN];
148     const char *dmname, *uname;
149 
150     PetscCall(PetscSNPrintf(stageName, PETSC_MAX_PATH_LEN - 1, "ConvEst Refinement Level %" PetscInt_FMT, r));
151 #if defined(PETSC_USE_LOG)
152     PetscCall(PetscLogStageGetId(stageName, &stage));
153     if (stage < 0) PetscCall(PetscLogStageRegister(stageName, &stage));
154 #endif
155     PetscCall(PetscLogStagePush(stage));
156     if (r > 0) {
157       if (!ce->noRefine) {
158         PetscCall(DMRefine(dm[r - 1], MPI_COMM_NULL, &dm[r]));
159         PetscCall(DMSetCoarseDM(dm[r], dm[r - 1]));
160       } else {
161         DM cdm, rcdm;
162 
163         PetscCall(DMClone(dm[r - 1], &dm[r]));
164         PetscCall(DMCopyDisc(dm[r - 1], dm[r]));
165         PetscCall(DMGetCoordinateDM(dm[r - 1], &cdm));
166         PetscCall(DMGetCoordinateDM(dm[r], &rcdm));
167         PetscCall(DMCopyDisc(cdm, rcdm));
168       }
169       PetscCall(DMCopyTransform(ce->idm, dm[r]));
170       PetscCall(PetscObjectGetName((PetscObject)dm[r - 1], &dmname));
171       PetscCall(PetscObjectSetName((PetscObject)dm[r], dmname));
172       for (f = 0; f <= Nf; ++f) {
173         PetscErrorCode (*nspconstr)(DM, PetscInt, PetscInt, MatNullSpace *);
174 
175         PetscCall(DMGetNullSpaceConstructor(dm[r - 1], f, &nspconstr));
176         PetscCall(DMSetNullSpaceConstructor(dm[r], f, nspconstr));
177       }
178     }
179     PetscCall(DMViewFromOptions(dm[r], NULL, "-conv_dm_view"));
180     /* Create solution */
181     PetscCall(DMCreateGlobalVector(dm[r], &u));
182     PetscCall(DMGetField(dm[r], 0, NULL, &disc));
183     PetscCall(PetscObjectGetName(disc, &uname));
184     PetscCall(PetscObjectSetName((PetscObject)u, uname));
185     /* Setup solver */
186     PetscCall(TSReset(ts));
187     PetscCall(TSSetDM(ts, dm[r]));
188     PetscCall(DMTSSetBoundaryLocal(dm[r], DMPlexTSComputeBoundary, ctx));
189     if (r > 0) {
190       PetscCall(DMTSGetIFunctionLocal(dm[r - 1], &ifunc, &fctx));
191       PetscCall(DMTSGetIJacobianLocal(dm[r - 1], &ijac, &jctx));
192       PetscCall(DMTSGetRHSFunctionLocal(dm[r - 1], &rhsfunc, &rctx));
193       if (ifunc) PetscCall(DMTSSetIFunctionLocal(dm[r], ifunc, fctx));
194       if (ijac) PetscCall(DMTSSetIJacobianLocal(dm[r], ijac, jctx));
195       if (rhsfunc) PetscCall(DMTSSetRHSFunctionLocal(dm[r], rhsfunc, rctx));
196     }
197     PetscCall(TSSetTime(ts, 0.0));
198     PetscCall(TSSetStepNumber(ts, 0));
199     PetscCall(TSSetFromOptions(ts));
200     PetscCall(TSSetSolution(ts, u));
201     PetscCall(VecDestroy(&u));
202     /* Create initial guess */
203     PetscCall(TSGetSolution(ts, &u));
204     PetscCall(PetscConvEstComputeInitialGuess(ce, r, dm[r], u));
205     PetscCall(TSSolve(ts, NULL));
206     PetscCall(TSGetSolution(ts, &u));
207     PetscCall(PetscLogEventBegin(ce->event, ce, 0, 0, 0));
208     PetscCall(PetscConvEstComputeError(ce, r, dm[r], u, &ce->errors[r * Nf]));
209     PetscCall(PetscLogEventEnd(ce->event, ce, 0, 0, 0));
210     for (f = 0; f < Nf; ++f) {
211       PetscSection s, fs;
212       PetscInt     lsize;
213 
214       /* Could use DMGetOutputDM() to add in Dirichlet dofs */
215       PetscCall(DMGetLocalSection(dm[r], &s));
216       PetscCall(PetscSectionGetField(s, f, &fs));
217       PetscCall(PetscSectionGetConstrainedStorageSize(fs, &lsize));
218       PetscCall(MPIU_Allreduce(&lsize, &ce->dofs[r * Nf + f], 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)ts)));
219       PetscCall(PetscLogEventSetDof(ce->event, f, ce->dofs[r * Nf + f]));
220       PetscCall(PetscLogEventSetError(ce->event, f, ce->errors[r * Nf + f]));
221     }
222     /* Monitor */
223     PetscCall(PetscConvEstMonitorDefault(ce, r));
224     if (!r) {
225       /* PCReset() does not wipe out the level structure */
226       SNES snes;
227       KSP  ksp;
228       PC   pc;
229 
230       PetscCall(TSGetSNES(ts, &snes));
231       PetscCall(SNESGetKSP(snes, &ksp));
232       PetscCall(KSPGetPC(ksp, &pc));
233       PetscCall(PCMGGetLevels(pc, &oldnlev));
234     }
235     /* Cleanup */
236     PetscCall(PetscLogStagePop());
237   }
238   PetscCall(DMTSGetIFunctionLocal(dm[r - 1], &ifunc, &fctx));
239   PetscCall(DMTSGetIJacobianLocal(dm[r - 1], &ijac, &jctx));
240   PetscCall(DMTSGetRHSFunctionLocal(dm[r - 1], &rhsfunc, &rctx));
241   for (r = 1; r <= Nr; ++r) PetscCall(DMDestroy(&dm[r]));
242   /* Fit convergence rate */
243   PetscCall(PetscMalloc2(Nr + 1, &x, Nr + 1, &y));
244   for (f = 0; f < Nf; ++f) {
245     for (r = 0; r <= Nr; ++r) {
246       x[r] = PetscLog10Real(ce->dofs[r * Nf + f]);
247       y[r] = PetscLog10Real(ce->errors[r * Nf + f]);
248     }
249     PetscCall(PetscLinearRegression(Nr + 1, x, y, &slope, &intercept));
250     /* Since h^{-dim} = N, lg err = s lg N + b = -s dim lg h + b */
251     alpha[f] = -slope * dim;
252   }
253   PetscCall(PetscFree2(x, y));
254   PetscCall(PetscFree(dm));
255   /* Restore solver */
256   PetscCall(TSReset(ts));
257   {
258     /* PCReset() does not wipe out the level structure */
259     SNES snes;
260     KSP  ksp;
261     PC   pc;
262 
263     PetscCall(TSGetSNES(ts, &snes));
264     PetscCall(SNESGetKSP(snes, &ksp));
265     PetscCall(KSPGetPC(ksp, &pc));
266     PetscCall(PCMGSetLevels(pc, oldnlev, NULL));
267     PetscCall(DMSetRefineLevel(ce->idm, oldlevel)); /* The damn DMCoarsen() calls in PCMG can reset this */
268   }
269   PetscCall(TSSetDM(ts, ce->idm));
270   PetscCall(DMTSSetBoundaryLocal(ce->idm, DMPlexTSComputeBoundary, ctx));
271   if (ifunc) PetscCall(DMTSSetIFunctionLocal(ce->idm, ifunc, fctx));
272   if (ijac) PetscCall(DMTSSetIJacobianLocal(ce->idm, ijac, jctx));
273   if (rhsfunc) PetscCall(DMTSSetRHSFunctionLocal(ce->idm, rhsfunc, rctx));
274   PetscCall(TSSetConvergedReason(ts, TS_CONVERGED_ITERATING));
275   PetscCall(TSSetTime(ts, 0.0));
276   PetscCall(TSSetStepNumber(ts, 0));
277   PetscCall(TSSetFromOptions(ts));
278   PetscCall(TSSetSolution(ts, uInitial));
279   PetscCall(PetscConvEstComputeInitialGuess(ce, 0, NULL, uInitial));
280   PetscCall(VecDestroy(&uInitial));
281   PetscFunctionReturn(PETSC_SUCCESS);
282 }
283 
284 PetscErrorCode PetscConvEstUseTS(PetscConvEst ce, PetscBool checkTemporal)
285 {
286   PetscFunctionBegin;
287   PetscValidHeaderSpecific(ce, PETSC_OBJECT_CLASSID, 1);
288   ce->ops->setsolver    = PetscConvEstSetTS_Private;
289   ce->ops->initguess    = PetscConvEstInitGuessTS_Private;
290   ce->ops->computeerror = PetscConvEstComputeErrorTS_Private;
291   if (checkTemporal) {
292     ce->ops->getconvrate = PetscConvEstGetConvRateTS_Temporal_Private;
293   } else {
294     ce->ops->getconvrate = PetscConvEstGetConvRateTS_Spatial_Private;
295   }
296   PetscFunctionReturn(PETSC_SUCCESS);
297 }
298