Actual source code: snescomposite.c
1: /*
2: Defines a SNES that can consist of a collection of SNESes
3: */
4: #include <petsc/private/snesimpl.h>
5: #include <petscblaslapack.h>
7: const char *const SNESCompositeTypes[] = {"ADDITIVE", "MULTIPLICATIVE", "ADDITIVEOPTIMAL", "SNESCompositeType", "SNES_COMPOSITE", NULL};
9: typedef struct _SNES_CompositeLink *SNES_CompositeLink;
10: struct _SNES_CompositeLink {
11: SNES snes;
12: PetscReal dmp;
13: Vec X;
14: SNES_CompositeLink next;
15: SNES_CompositeLink previous;
16: };
18: typedef struct {
19: SNES_CompositeLink head;
20: PetscInt nsnes;
21: SNESCompositeType type;
22: Vec Xorig;
23: PetscInt innerFailures; /* the number of inner failures we've seen */
25: /* context for ADDITIVEOPTIMAL */
26: Vec *Xes, *Fes; /* solution and residual vectors for the subsolvers */
27: PetscReal *fnorms; /* norms of the solutions */
28: PetscScalar *h; /* the matrix formed as q_ij = (rdot_i, rdot_j) */
29: PetscScalar *g; /* the dotproducts of the previous function with the candidate functions */
30: PetscBLASInt n; /* matrix dimension -- nsnes */
31: PetscBLASInt nrhs; /* the number of right hand sides */
32: PetscBLASInt lda; /* the padded matrix dimension */
33: PetscBLASInt ldb; /* the padded vector dimension */
34: PetscReal *s; /* the singular values */
35: PetscScalar *beta; /* the RHS and combination */
36: PetscReal rcond; /* the exit condition */
37: PetscBLASInt rank; /* the effective rank */
38: PetscScalar *work; /* the work vector */
39: PetscReal *rwork; /* the real work vector used for complex */
40: PetscBLASInt lwork; /* the size of the work vector */
41: PetscBLASInt info; /* the output condition */
43: PetscReal rtol; /* restart tolerance for accepting the combination */
44: PetscReal stol; /* restart tolerance for the combination */
45: } SNES_Composite;
47: static PetscErrorCode SNESCompositeApply_Multiplicative(SNES snes, Vec X, Vec B, Vec F, PetscReal *fnorm)
48: {
49: SNES_Composite *jac = (SNES_Composite *)snes->data;
50: SNES_CompositeLink next = jac->head;
51: Vec FSub;
52: SNESConvergedReason reason;
54: PetscFunctionBegin;
55: PetscCheck(next, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "No composite SNESes supplied via SNESCompositeAddSNES() or -snes_composite_sneses");
56: if (snes->normschedule == SNES_NORM_ALWAYS) PetscCall(SNESSetInitialFunction(next->snes, F));
57: PetscCall(SNESSolve(next->snes, B, X));
58: PetscCall(SNESGetConvergedReason(next->snes, &reason));
59: if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) {
60: jac->innerFailures++;
61: if (jac->innerFailures >= snes->maxFailures) {
62: snes->reason = SNES_DIVERGED_INNER;
63: PetscFunctionReturn(PETSC_SUCCESS);
64: }
65: }
67: while (next->next) {
68: /* only copy the function over in the case where the functions correspond */
69: if (next->snes->npcside == PC_RIGHT && next->snes->normschedule != SNES_NORM_NONE) {
70: PetscCall(SNESGetFunction(next->snes, &FSub, NULL, NULL));
71: next = next->next;
72: PetscCall(SNESSetInitialFunction(next->snes, FSub));
73: } else {
74: next = next->next;
75: }
76: PetscCall(SNESSolve(next->snes, B, X));
77: PetscCall(SNESGetConvergedReason(next->snes, &reason));
78: if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) {
79: jac->innerFailures++;
80: if (jac->innerFailures >= snes->maxFailures) {
81: snes->reason = SNES_DIVERGED_INNER;
82: PetscFunctionReturn(PETSC_SUCCESS);
83: }
84: }
85: }
86: if (next->snes->npcside == PC_RIGHT) {
87: PetscCall(SNESGetFunction(next->snes, &FSub, NULL, NULL));
88: PetscCall(VecCopy(FSub, F));
89: if (fnorm) {
90: if (snes->xl && snes->xu) {
91: PetscCall(SNESVIComputeInactiveSetFnorm(snes, F, X, fnorm));
92: } else {
93: PetscCall(VecNorm(F, NORM_2, fnorm));
94: }
95: SNESCheckFunctionNorm(snes, *fnorm);
96: }
97: } else if (snes->normschedule == SNES_NORM_ALWAYS) {
98: PetscCall(SNESComputeFunction(snes, X, F));
99: if (fnorm) {
100: if (snes->xl && snes->xu) {
101: PetscCall(SNESVIComputeInactiveSetFnorm(snes, F, X, fnorm));
102: } else {
103: PetscCall(VecNorm(F, NORM_2, fnorm));
104: }
105: SNESCheckFunctionNorm(snes, *fnorm);
106: }
107: }
108: PetscFunctionReturn(PETSC_SUCCESS);
109: }
111: static PetscErrorCode SNESCompositeApply_Additive(SNES snes, Vec X, Vec B, Vec F, PetscReal *fnorm)
112: {
113: SNES_Composite *jac = (SNES_Composite *)snes->data;
114: SNES_CompositeLink next = jac->head;
115: Vec Y, Xorig;
116: SNESConvergedReason reason;
118: PetscFunctionBegin;
119: Y = snes->vec_sol_update;
120: if (!jac->Xorig) PetscCall(VecDuplicate(X, &jac->Xorig));
121: Xorig = jac->Xorig;
122: PetscCall(VecCopy(X, Xorig));
123: PetscCheck(next, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "No composite SNESes supplied via SNESCompositeAddSNES() or -snes_composite_sneses");
124: if (snes->normschedule == SNES_NORM_ALWAYS) {
125: PetscCall(SNESSetInitialFunction(next->snes, F));
126: while (next->next) {
127: next = next->next;
128: PetscCall(SNESSetInitialFunction(next->snes, F));
129: }
130: }
131: next = jac->head;
132: PetscCall(VecCopy(Xorig, Y));
133: PetscCall(SNESSolve(next->snes, B, Y));
134: PetscCall(SNESGetConvergedReason(next->snes, &reason));
135: if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) {
136: jac->innerFailures++;
137: if (jac->innerFailures >= snes->maxFailures) {
138: snes->reason = SNES_DIVERGED_INNER;
139: PetscFunctionReturn(PETSC_SUCCESS);
140: }
141: }
142: PetscCall(VecAXPY(Y, -1.0, Xorig));
143: PetscCall(VecAXPY(X, next->dmp, Y));
144: while (next->next) {
145: next = next->next;
146: PetscCall(VecCopy(Xorig, Y));
147: PetscCall(SNESSolve(next->snes, B, Y));
148: PetscCall(SNESGetConvergedReason(next->snes, &reason));
149: if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) {
150: jac->innerFailures++;
151: if (jac->innerFailures >= snes->maxFailures) {
152: snes->reason = SNES_DIVERGED_INNER;
153: PetscFunctionReturn(PETSC_SUCCESS);
154: }
155: }
156: PetscCall(VecAXPY(Y, -1.0, Xorig));
157: PetscCall(VecAXPY(X, next->dmp, Y));
158: }
159: if (snes->normschedule == SNES_NORM_ALWAYS) {
160: PetscCall(SNESComputeFunction(snes, X, F));
161: if (fnorm) {
162: if (snes->xl && snes->xu) {
163: PetscCall(SNESVIComputeInactiveSetFnorm(snes, F, X, fnorm));
164: } else {
165: PetscCall(VecNorm(F, NORM_2, fnorm));
166: }
167: SNESCheckFunctionNorm(snes, *fnorm);
168: }
169: }
170: PetscFunctionReturn(PETSC_SUCCESS);
171: }
173: /* approximately solve the overdetermined system:
175: 2*F(x_i)\cdot F(\x_j)\alpha_i = 0
176: \alpha_i = 1
178: Which minimizes the L2 norm of the linearization of:
179: ||F(\sum_i \alpha_i*x_i)||^2
181: With the constraint that \sum_i\alpha_i = 1
182: Where x_i is the solution from the ith subsolver.
183: */
184: static PetscErrorCode SNESCompositeApply_AdditiveOptimal(SNES snes, Vec X, Vec B, Vec F, PetscReal *fnorm)
185: {
186: SNES_Composite *jac = (SNES_Composite *)snes->data;
187: SNES_CompositeLink next = jac->head;
188: Vec *Xes = jac->Xes, *Fes = jac->Fes;
189: PetscInt i, j;
190: PetscScalar tot, total, ftf;
191: PetscReal min_fnorm;
192: PetscInt min_i;
193: SNESConvergedReason reason;
195: PetscFunctionBegin;
196: PetscCheck(next, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "No composite SNESes supplied via SNESCompositeAddSNES() or -snes_composite_sneses");
198: if (snes->normschedule == SNES_NORM_ALWAYS) {
199: next = jac->head;
200: PetscCall(SNESSetInitialFunction(next->snes, F));
201: while (next->next) {
202: next = next->next;
203: PetscCall(SNESSetInitialFunction(next->snes, F));
204: }
205: }
207: next = jac->head;
208: i = 0;
209: PetscCall(VecCopy(X, Xes[i]));
210: PetscCall(SNESSolve(next->snes, B, Xes[i]));
211: PetscCall(SNESGetConvergedReason(next->snes, &reason));
212: if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) {
213: jac->innerFailures++;
214: if (jac->innerFailures >= snes->maxFailures) {
215: snes->reason = SNES_DIVERGED_INNER;
216: PetscFunctionReturn(PETSC_SUCCESS);
217: }
218: }
219: while (next->next) {
220: i++;
221: next = next->next;
222: PetscCall(VecCopy(X, Xes[i]));
223: PetscCall(SNESSolve(next->snes, B, Xes[i]));
224: PetscCall(SNESGetConvergedReason(next->snes, &reason));
225: if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) {
226: jac->innerFailures++;
227: if (jac->innerFailures >= snes->maxFailures) {
228: snes->reason = SNES_DIVERGED_INNER;
229: PetscFunctionReturn(PETSC_SUCCESS);
230: }
231: }
232: }
234: /* all the solutions are collected; combine optimally */
235: for (i = 0; i < jac->n; i++) {
236: for (j = 0; j < i + 1; j++) PetscCall(VecDotBegin(Fes[i], Fes[j], &jac->h[i + j * jac->n]));
237: PetscCall(VecDotBegin(Fes[i], F, &jac->g[i]));
238: }
240: for (i = 0; i < jac->n; i++) {
241: for (j = 0; j < i + 1; j++) {
242: PetscCall(VecDotEnd(Fes[i], Fes[j], &jac->h[i + j * jac->n]));
243: if (i == j) jac->fnorms[i] = PetscSqrtReal(PetscRealPart(jac->h[i + j * jac->n]));
244: }
245: PetscCall(VecDotEnd(Fes[i], F, &jac->g[i]));
246: }
248: ftf = (*fnorm) * (*fnorm);
250: for (i = 0; i < jac->n; i++) {
251: for (j = i + 1; j < jac->n; j++) jac->h[i + j * jac->n] = jac->h[j + i * jac->n];
252: }
254: for (i = 0; i < jac->n; i++) {
255: for (j = 0; j < jac->n; j++) jac->h[i + j * jac->n] = jac->h[i + j * jac->n] - jac->g[j] - jac->g[i] + ftf;
256: jac->beta[i] = ftf - jac->g[i];
257: }
259: jac->info = 0;
260: jac->rcond = -1.;
261: PetscCall(PetscFPTrapPush(PETSC_FP_TRAP_OFF));
262: #if defined(PETSC_USE_COMPLEX)
263: PetscCallBLAS("LAPACKgelss", LAPACKgelss_(&jac->n, &jac->n, &jac->nrhs, jac->h, &jac->lda, jac->beta, &jac->lda, jac->s, &jac->rcond, &jac->rank, jac->work, &jac->lwork, jac->rwork, &jac->info));
264: #else
265: PetscCallBLAS("LAPACKgelss", LAPACKgelss_(&jac->n, &jac->n, &jac->nrhs, jac->h, &jac->lda, jac->beta, &jac->lda, jac->s, &jac->rcond, &jac->rank, jac->work, &jac->lwork, &jac->info));
266: #endif
267: PetscCall(PetscFPTrapPop());
268: PetscCheck(jac->info >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_LIB, "Bad argument to GELSS");
269: PetscCheck(jac->info <= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_LIB, "SVD failed to converge");
270: tot = 0.;
271: total = 0.;
272: for (i = 0; i < jac->n; i++) {
273: PetscCheck(!snes->errorifnotconverged || !PetscIsInfOrNanScalar(jac->beta[i]), PetscObjectComm((PetscObject)snes), PETSC_ERR_LIB, "SVD generated inconsistent output");
274: PetscCall(PetscInfo(snes, "%" PetscInt_FMT ": %g\n", i, (double)PetscRealPart(jac->beta[i])));
275: tot += jac->beta[i];
276: total += PetscAbsScalar(jac->beta[i]);
277: }
278: PetscCall(VecScale(X, (1. - tot)));
279: PetscCall(VecMAXPY(X, jac->n, jac->beta, Xes));
280: PetscCall(SNESComputeFunction(snes, X, F));
282: if (snes->xl && snes->xu) {
283: PetscCall(SNESVIComputeInactiveSetFnorm(snes, F, X, fnorm));
284: } else {
285: PetscCall(VecNorm(F, NORM_2, fnorm));
286: }
288: /* take the minimum-normed candidate if it beats the combination by a factor of rtol or the combination has stagnated */
289: min_fnorm = jac->fnorms[0];
290: min_i = 0;
291: for (i = 0; i < jac->n; i++) {
292: if (jac->fnorms[i] < min_fnorm) {
293: min_fnorm = jac->fnorms[i];
294: min_i = i;
295: }
296: }
298: /* stagnation or divergence restart to the solution of the solver that failed the least */
299: if (PetscRealPart(total) < jac->stol || min_fnorm * jac->rtol < *fnorm) {
300: PetscCall(VecCopy(jac->Xes[min_i], X));
301: PetscCall(VecCopy(jac->Fes[min_i], F));
302: *fnorm = min_fnorm;
303: }
304: PetscFunctionReturn(PETSC_SUCCESS);
305: }
307: static PetscErrorCode SNESSetUp_Composite(SNES snes)
308: {
309: DM dm;
310: SNES_Composite *jac = (SNES_Composite *)snes->data;
311: SNES_CompositeLink next = jac->head;
312: PetscInt n = 0, i;
313: Vec F;
315: PetscFunctionBegin;
316: PetscCall(SNESGetDM(snes, &dm));
318: if (snes->ops->computevariablebounds) {
319: /* SNESVI only ever calls computevariablebounds once, so calling it once here is justified */
320: if (!snes->xl) PetscCall(VecDuplicate(snes->vec_sol, &snes->xl));
321: if (!snes->xu) PetscCall(VecDuplicate(snes->vec_sol, &snes->xu));
322: PetscUseTypeMethod(snes, computevariablebounds, snes->xl, snes->xu);
323: }
325: while (next) {
326: n++;
327: PetscCall(SNESSetDM(next->snes, dm));
328: PetscCall(SNESSetApplicationContext(next->snes, snes->user));
329: if (snes->xl && snes->xu) {
330: if (snes->ops->computevariablebounds) {
331: PetscCall(SNESVISetComputeVariableBounds(next->snes, snes->ops->computevariablebounds));
332: } else {
333: PetscCall(SNESVISetVariableBounds(next->snes, snes->xl, snes->xu));
334: }
335: }
337: next = next->next;
338: }
339: jac->nsnes = n;
340: PetscCall(SNESGetFunction(snes, &F, NULL, NULL));
341: if (jac->type == SNES_COMPOSITE_ADDITIVEOPTIMAL) {
342: PetscCall(VecDuplicateVecs(F, jac->nsnes, &jac->Xes));
343: PetscCall(PetscMalloc1(n, &jac->Fes));
344: PetscCall(PetscMalloc1(n, &jac->fnorms));
345: next = jac->head;
346: i = 0;
347: while (next) {
348: PetscCall(SNESGetFunction(next->snes, &F, NULL, NULL));
349: jac->Fes[i] = F;
350: PetscCall(PetscObjectReference((PetscObject)F));
351: next = next->next;
352: i++;
353: }
354: /* allocate the subspace direct solve area */
355: jac->nrhs = 1;
356: jac->lda = jac->nsnes;
357: jac->ldb = jac->nsnes;
358: jac->n = jac->nsnes;
360: PetscCall(PetscMalloc1(jac->n * jac->n, &jac->h));
361: PetscCall(PetscMalloc1(jac->n, &jac->beta));
362: PetscCall(PetscMalloc1(jac->n, &jac->s));
363: PetscCall(PetscMalloc1(jac->n, &jac->g));
364: jac->lwork = 12 * jac->n;
365: #if defined(PETSC_USE_COMPLEX)
366: PetscCall(PetscMalloc1(jac->lwork, &jac->rwork));
367: #endif
368: PetscCall(PetscMalloc1(jac->lwork, &jac->work));
369: }
371: PetscFunctionReturn(PETSC_SUCCESS);
372: }
374: static PetscErrorCode SNESReset_Composite(SNES snes)
375: {
376: SNES_Composite *jac = (SNES_Composite *)snes->data;
377: SNES_CompositeLink next = jac->head;
379: PetscFunctionBegin;
380: while (next) {
381: PetscCall(SNESReset(next->snes));
382: next = next->next;
383: }
384: PetscCall(VecDestroy(&jac->Xorig));
385: if (jac->Xes) PetscCall(VecDestroyVecs(jac->nsnes, &jac->Xes));
386: if (jac->Fes) PetscCall(VecDestroyVecs(jac->nsnes, &jac->Fes));
387: PetscCall(PetscFree(jac->fnorms));
388: PetscCall(PetscFree(jac->h));
389: PetscCall(PetscFree(jac->s));
390: PetscCall(PetscFree(jac->g));
391: PetscCall(PetscFree(jac->beta));
392: PetscCall(PetscFree(jac->work));
393: PetscCall(PetscFree(jac->rwork));
394: PetscFunctionReturn(PETSC_SUCCESS);
395: }
397: static PetscErrorCode SNESDestroy_Composite(SNES snes)
398: {
399: SNES_Composite *jac = (SNES_Composite *)snes->data;
400: SNES_CompositeLink next = jac->head, next_tmp;
402: PetscFunctionBegin;
403: PetscCall(SNESReset_Composite(snes));
404: while (next) {
405: PetscCall(SNESDestroy(&next->snes));
406: next_tmp = next;
407: next = next->next;
408: PetscCall(PetscFree(next_tmp));
409: }
410: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESCompositeSetType_C", NULL));
411: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESCompositeAddSNES_C", NULL));
412: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESCompositeGetSNES_C", NULL));
413: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESCompositeSetDamping_C", NULL));
414: PetscCall(PetscFree(snes->data));
415: PetscFunctionReturn(PETSC_SUCCESS);
416: }
418: static PetscErrorCode SNESSetFromOptions_Composite(SNES snes, PetscOptionItems *PetscOptionsObject)
419: {
420: SNES_Composite *jac = (SNES_Composite *)snes->data;
421: PetscInt nmax = 8, i;
422: SNES_CompositeLink next;
423: char *sneses[8];
424: PetscReal dmps[8];
425: PetscBool flg;
427: PetscFunctionBegin;
428: PetscOptionsHeadBegin(PetscOptionsObject, "Composite preconditioner options");
429: PetscCall(PetscOptionsEnum("-snes_composite_type", "Type of composition", "SNESCompositeSetType", SNESCompositeTypes, (PetscEnum)jac->type, (PetscEnum *)&jac->type, &flg));
430: if (flg) PetscCall(SNESCompositeSetType(snes, jac->type));
431: PetscCall(PetscOptionsStringArray("-snes_composite_sneses", "List of composite solvers", "SNESCompositeAddSNES", sneses, &nmax, &flg));
432: if (flg) {
433: for (i = 0; i < nmax; i++) {
434: PetscCall(SNESCompositeAddSNES(snes, sneses[i]));
435: PetscCall(PetscFree(sneses[i])); /* deallocate string sneses[i], which is allocated in PetscOptionsStringArray() */
436: }
437: }
438: PetscCall(PetscOptionsRealArray("-snes_composite_damping", "Damping of the additive composite solvers", "SNESCompositeSetDamping", dmps, &nmax, &flg));
439: if (flg) {
440: for (i = 0; i < nmax; i++) PetscCall(SNESCompositeSetDamping(snes, i, dmps[i]));
441: }
442: PetscCall(PetscOptionsReal("-snes_composite_stol", "Step tolerance for restart on the additive composite solvers", "", jac->stol, &jac->stol, NULL));
443: PetscCall(PetscOptionsReal("-snes_composite_rtol", "Residual tolerance for the additive composite solvers", "", jac->rtol, &jac->rtol, NULL));
444: PetscOptionsHeadEnd();
446: next = jac->head;
447: while (next) {
448: PetscCall(SNESSetFromOptions(next->snes));
449: next = next->next;
450: }
451: PetscFunctionReturn(PETSC_SUCCESS);
452: }
454: static PetscErrorCode SNESView_Composite(SNES snes, PetscViewer viewer)
455: {
456: SNES_Composite *jac = (SNES_Composite *)snes->data;
457: SNES_CompositeLink next = jac->head;
458: PetscBool iascii;
460: PetscFunctionBegin;
461: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
462: if (iascii) {
463: PetscCall(PetscViewerASCIIPrintf(viewer, " type - %s\n", SNESCompositeTypes[jac->type]));
464: PetscCall(PetscViewerASCIIPrintf(viewer, " SNESes on composite preconditioner follow\n"));
465: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------------------------------\n"));
466: }
467: if (iascii) PetscCall(PetscViewerASCIIPushTab(viewer));
468: while (next) {
469: PetscCall(SNESView(next->snes, viewer));
470: next = next->next;
471: }
472: if (iascii) {
473: PetscCall(PetscViewerASCIIPopTab(viewer));
474: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------------------------------\n"));
475: }
476: PetscFunctionReturn(PETSC_SUCCESS);
477: }
479: static PetscErrorCode SNESCompositeSetType_Composite(SNES snes, SNESCompositeType type)
480: {
481: SNES_Composite *jac = (SNES_Composite *)snes->data;
483: PetscFunctionBegin;
484: jac->type = type;
485: PetscFunctionReturn(PETSC_SUCCESS);
486: }
488: static PetscErrorCode SNESCompositeAddSNES_Composite(SNES snes, SNESType type)
489: {
490: SNES_Composite *jac;
491: SNES_CompositeLink next, ilink;
492: PetscInt cnt = 0;
493: const char *prefix;
494: char newprefix[20];
495: DM dm;
497: PetscFunctionBegin;
498: PetscCall(PetscNew(&ilink));
499: ilink->next = NULL;
500: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &ilink->snes));
501: PetscCall(SNESGetDM(snes, &dm));
502: PetscCall(SNESSetDM(ilink->snes, dm));
503: PetscCall(SNESSetTolerances(ilink->snes, snes->abstol, snes->rtol, snes->stol, 1, snes->max_funcs));
504: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)ilink->snes));
505: jac = (SNES_Composite *)snes->data;
506: next = jac->head;
507: if (!next) {
508: jac->head = ilink;
509: ilink->previous = NULL;
510: } else {
511: cnt++;
512: while (next->next) {
513: next = next->next;
514: cnt++;
515: }
516: next->next = ilink;
517: ilink->previous = next;
518: }
519: PetscCall(SNESGetOptionsPrefix(snes, &prefix));
520: PetscCall(SNESSetOptionsPrefix(ilink->snes, prefix));
521: PetscCall(PetscSNPrintf(newprefix, sizeof(newprefix), "sub_%d_", (int)cnt));
522: PetscCall(SNESAppendOptionsPrefix(ilink->snes, newprefix));
523: PetscCall(PetscObjectIncrementTabLevel((PetscObject)ilink->snes, (PetscObject)snes, 1));
524: PetscCall(SNESSetType(ilink->snes, type));
525: PetscCall(SNESSetNormSchedule(ilink->snes, SNES_NORM_FINAL_ONLY));
527: ilink->dmp = 1.0;
528: jac->nsnes++;
529: PetscFunctionReturn(PETSC_SUCCESS);
530: }
532: static PetscErrorCode SNESCompositeGetSNES_Composite(SNES snes, PetscInt n, SNES *subsnes)
533: {
534: SNES_Composite *jac;
535: SNES_CompositeLink next;
536: PetscInt i;
538: PetscFunctionBegin;
539: jac = (SNES_Composite *)snes->data;
540: next = jac->head;
541: for (i = 0; i < n; i++) {
542: PetscCheck(next->next, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "Not enough SNESes in composite preconditioner");
543: next = next->next;
544: }
545: *subsnes = next->snes;
546: PetscFunctionReturn(PETSC_SUCCESS);
547: }
549: /*@C
550: SNESCompositeSetType - Sets the type of composite preconditioner.
552: Logically Collective
554: Input Parameters:
555: + snes - the preconditioner context
556: - type - `SNES_COMPOSITE_ADDITIVE` (default), `SNES_COMPOSITE_MULTIPLICATIVE`, or `SNES_COMPOSITE_ADDITIVEOPTIMAL`
558: Options Database Key:
559: . -snes_composite_type <type: one of multiplicative, additive, additiveoptimal> - Sets composite preconditioner type
561: Level: developer
563: .seealso: [](ch_snes), `SNES_COMPOSITE_ADDITIVE`, `SNES_COMPOSITE_MULTIPLICATIVE`, `SNESCompositeType`, `SNESCOMPOSITE`, `SNES_COMPOSITE_ADDITIVEOPTIMAL`,
564: `PCCompositeType`
565: @*/
566: PetscErrorCode SNESCompositeSetType(SNES snes, SNESCompositeType type)
567: {
568: PetscFunctionBegin;
571: PetscTryMethod(snes, "SNESCompositeSetType_C", (SNES, SNESCompositeType), (snes, type));
572: PetscFunctionReturn(PETSC_SUCCESS);
573: }
575: /*@C
576: SNESCompositeAddSNES - Adds another `SNES` to the `SNESCOMPOSITE`
578: Collective
580: Input Parameters:
581: + snes - the `SNES` context of type `SNESCOMPOSITE`
582: - type - the `SNESType` of the new solver
584: Level: developer
586: .seealso: [](ch_snes), `SNES`, `SNESCOMPOSITE`, `SNESCompositeGetSNES()`
587: @*/
588: PetscErrorCode SNESCompositeAddSNES(SNES snes, SNESType type)
589: {
590: PetscFunctionBegin;
592: PetscTryMethod(snes, "SNESCompositeAddSNES_C", (SNES, SNESType), (snes, type));
593: PetscFunctionReturn(PETSC_SUCCESS);
594: }
596: /*@
597: SNESCompositeGetSNES - Gets one of the `SNES` objects in the `SNES` of `SNESType` `SNESCOMPOSITE`
599: Not Collective
601: Input Parameters:
602: + snes - the `SNES` context
603: - n - the number of the composed `SNES` requested
605: Output Parameter:
606: . subsnes - the `SNES` requested
608: Level: developer
610: .seealso: [](ch_snes), `SNES`, `SNESCOMPOSITE`, `SNESCompositeAddSNES()`, `SNESCompositeGetNumber()`
611: @*/
612: PetscErrorCode SNESCompositeGetSNES(SNES snes, PetscInt n, SNES *subsnes)
613: {
614: PetscFunctionBegin;
616: PetscAssertPointer(subsnes, 3);
617: PetscUseMethod(snes, "SNESCompositeGetSNES_C", (SNES, PetscInt, SNES *), (snes, n, subsnes));
618: PetscFunctionReturn(PETSC_SUCCESS);
619: }
621: /*@
622: SNESCompositeGetNumber - Get the number of subsolvers in the `SNESCOMPOSITE`
624: Logically Collective
626: Input Parameter:
627: . snes - the `SNES` context
629: Output Parameter:
630: . n - the number of subsolvers
632: Level: developer
634: .seealso: [](ch_snes), `SNES`, `SNESCOMPOSITE`, `SNESCompositeAddSNES()`, `SNESCompositeGetSNES()`
635: @*/
636: PetscErrorCode SNESCompositeGetNumber(SNES snes, PetscInt *n)
637: {
638: SNES_Composite *jac;
639: SNES_CompositeLink next;
641: PetscFunctionBegin;
642: jac = (SNES_Composite *)snes->data;
643: next = jac->head;
645: *n = 0;
646: while (next) {
647: *n = *n + 1;
648: next = next->next;
649: }
650: PetscFunctionReturn(PETSC_SUCCESS);
651: }
653: static PetscErrorCode SNESCompositeSetDamping_Composite(SNES snes, PetscInt n, PetscReal dmp)
654: {
655: SNES_Composite *jac;
656: SNES_CompositeLink next;
657: PetscInt i;
659: PetscFunctionBegin;
660: jac = (SNES_Composite *)snes->data;
661: next = jac->head;
662: for (i = 0; i < n; i++) {
663: PetscCheck(next->next, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "Not enough SNESes in composite preconditioner");
664: next = next->next;
665: }
666: next->dmp = dmp;
667: PetscFunctionReturn(PETSC_SUCCESS);
668: }
670: /*@
671: SNESCompositeSetDamping - Sets the damping of a subsolver when using `SNES_COMPOSITE_ADDITIVE` with a `SNES` of `SNESType` `SNESCOMPOSITE`
673: Not Collective
675: Input Parameters:
676: + snes - the `SNES` context
677: . n - the number of the sub-`SNES` object requested
678: - dmp - the damping
680: Level: intermediate
682: .seealso: [](ch_snes), `SNES`, `SNESCOMPOSITE`, `SNESCompositeAddSNES()`, `SNESCompositeGetSNES()`,
683: `SNES_COMPOSITE_ADDITIVE`, `SNES_COMPOSITE_MULTIPLICATIVE`, `SNESCompositeType`, `SNESCompositeSetType()`
684: @*/
685: PetscErrorCode SNESCompositeSetDamping(SNES snes, PetscInt n, PetscReal dmp)
686: {
687: PetscFunctionBegin;
689: PetscUseMethod(snes, "SNESCompositeSetDamping_C", (SNES, PetscInt, PetscReal), (snes, n, dmp));
690: PetscFunctionReturn(PETSC_SUCCESS);
691: }
693: static PetscErrorCode SNESSolve_Composite(SNES snes)
694: {
695: Vec F, X, B, Y;
696: PetscInt i;
697: PetscReal fnorm = 0.0, xnorm = 0.0, snorm = 0.0;
698: SNESNormSchedule normtype;
699: SNES_Composite *comp = (SNES_Composite *)snes->data;
701: PetscFunctionBegin;
702: X = snes->vec_sol;
703: F = snes->vec_func;
704: B = snes->vec_rhs;
705: Y = snes->vec_sol_update;
707: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
708: snes->iter = 0;
709: snes->norm = 0.;
710: comp->innerFailures = 0;
711: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
712: snes->reason = SNES_CONVERGED_ITERATING;
713: PetscCall(SNESGetNormSchedule(snes, &normtype));
714: if (normtype == SNES_NORM_ALWAYS || normtype == SNES_NORM_INITIAL_ONLY || normtype == SNES_NORM_INITIAL_FINAL_ONLY) {
715: if (!snes->vec_func_init_set) {
716: PetscCall(SNESComputeFunction(snes, X, F));
717: } else snes->vec_func_init_set = PETSC_FALSE;
719: if (snes->xl && snes->xu) {
720: PetscCall(SNESVIComputeInactiveSetFnorm(snes, F, X, &fnorm));
721: } else {
722: PetscCall(VecNorm(F, NORM_2, &fnorm)); /* fnorm <- ||F|| */
723: }
724: SNESCheckFunctionNorm(snes, fnorm);
725: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
726: snes->iter = 0;
727: snes->norm = fnorm;
728: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
729: PetscCall(SNESLogConvergenceHistory(snes, snes->norm, 0));
731: /* test convergence */
732: PetscCall(SNESConverged(snes, 0, 0.0, 0.0, fnorm));
733: PetscCall(SNESMonitor(snes, 0, snes->norm));
734: if (snes->reason) PetscFunctionReturn(PETSC_SUCCESS);
735: } else {
736: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
737: PetscCall(SNESLogConvergenceHistory(snes, snes->norm, 0));
738: PetscCall(SNESMonitor(snes, 0, snes->norm));
739: }
741: for (i = 0; i < snes->max_its; i++) {
742: /* Call general purpose update function */
743: PetscTryTypeMethod(snes, update, snes->iter);
745: /* Copy the state before modification by application of the composite solver;
746: we will subtract the new state after application */
747: PetscCall(VecCopy(X, Y));
749: if (comp->type == SNES_COMPOSITE_ADDITIVE) {
750: PetscCall(SNESCompositeApply_Additive(snes, X, B, F, &fnorm));
751: } else if (comp->type == SNES_COMPOSITE_MULTIPLICATIVE) {
752: PetscCall(SNESCompositeApply_Multiplicative(snes, X, B, F, &fnorm));
753: } else if (comp->type == SNES_COMPOSITE_ADDITIVEOPTIMAL) {
754: PetscCall(SNESCompositeApply_AdditiveOptimal(snes, X, B, F, &fnorm));
755: } else SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "Unsupported SNESComposite type");
756: if (snes->reason < 0) break;
758: /* Compute the solution update for convergence testing */
759: PetscCall(VecAYPX(Y, -1.0, X));
761: if ((i == snes->max_its - 1) && (normtype == SNES_NORM_INITIAL_FINAL_ONLY || normtype == SNES_NORM_FINAL_ONLY)) {
762: PetscCall(SNESComputeFunction(snes, X, F));
764: if (snes->xl && snes->xu) {
765: PetscCall(VecNormBegin(X, NORM_2, &xnorm));
766: PetscCall(VecNormBegin(Y, NORM_2, &snorm));
767: PetscCall(SNESVIComputeInactiveSetFnorm(snes, F, X, &fnorm));
768: PetscCall(VecNormEnd(X, NORM_2, &xnorm));
769: PetscCall(VecNormEnd(Y, NORM_2, &snorm));
770: } else {
771: PetscCall(VecNormBegin(F, NORM_2, &fnorm));
772: PetscCall(VecNormBegin(X, NORM_2, &xnorm));
773: PetscCall(VecNormBegin(Y, NORM_2, &snorm));
775: PetscCall(VecNormEnd(F, NORM_2, &fnorm));
776: PetscCall(VecNormEnd(X, NORM_2, &xnorm));
777: PetscCall(VecNormEnd(Y, NORM_2, &snorm));
778: }
779: SNESCheckFunctionNorm(snes, fnorm);
780: } else if (normtype == SNES_NORM_ALWAYS) {
781: PetscCall(VecNormBegin(X, NORM_2, &xnorm));
782: PetscCall(VecNormBegin(Y, NORM_2, &snorm));
783: PetscCall(VecNormEnd(X, NORM_2, &xnorm));
784: PetscCall(VecNormEnd(Y, NORM_2, &snorm));
785: }
786: /* Monitor convergence */
787: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
788: snes->iter = i + 1;
789: snes->norm = fnorm;
790: snes->xnorm = xnorm;
791: snes->ynorm = snorm;
792: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
793: PetscCall(SNESLogConvergenceHistory(snes, snes->norm, 0));
794: /* Test for convergence */
795: PetscCall(SNESConverged(snes, snes->iter, xnorm, snorm, fnorm));
796: PetscCall(SNESMonitor(snes, snes->iter, snes->norm));
797: if (snes->reason) break;
798: }
799: PetscFunctionReturn(PETSC_SUCCESS);
800: }
802: /*MC
803: SNESCOMPOSITE - Builds a nonlinear solver/preconditioner by composing together several `SNES` nonlinear solvers {cite}`bruneknepleysmithtu15`
805: Options Database Keys:
806: + -snes_composite_type <type: one of multiplicative, additive, additiveoptimal> - Sets composite preconditioner type
807: - -snes_composite_sneses - <snes0,snes1,...> list of `SNES` to compose
809: Level: intermediate
811: .seealso: [](ch_snes), `SNES`, `SNESCOMPOSITE`, `SNESCompositeAddSNES()`, `SNESCompositeGetSNES()`,
812: `SNES_COMPOSITE_ADDITIVE`, `SNES_COMPOSITE_ADDITIVEOPTIMAL`, `SNES_COMPOSITE_MULTIPLICATIVE`, `SNESCompositeType`,
813: `SNESCompositeSetType()`, `SNESCompositeSetDamping()`, `SNESCompositeGetNumber()`, `PCCompositeType`
814: M*/
816: PETSC_EXTERN PetscErrorCode SNESCreate_Composite(SNES snes)
817: {
818: SNES_Composite *jac;
820: PetscFunctionBegin;
821: PetscCall(PetscNew(&jac));
823: snes->ops->solve = SNESSolve_Composite;
824: snes->ops->setup = SNESSetUp_Composite;
825: snes->ops->reset = SNESReset_Composite;
826: snes->ops->destroy = SNESDestroy_Composite;
827: snes->ops->setfromoptions = SNESSetFromOptions_Composite;
828: snes->ops->view = SNESView_Composite;
830: snes->usesksp = PETSC_FALSE;
832: snes->alwayscomputesfinalresidual = PETSC_FALSE;
834: snes->data = (void *)jac;
835: jac->type = SNES_COMPOSITE_ADDITIVEOPTIMAL;
836: jac->Fes = NULL;
837: jac->Xes = NULL;
838: jac->fnorms = NULL;
839: jac->nsnes = 0;
840: jac->head = NULL;
841: jac->stol = 0.1;
842: jac->rtol = 1.1;
844: jac->h = NULL;
845: jac->s = NULL;
846: jac->beta = NULL;
847: jac->work = NULL;
848: jac->rwork = NULL;
850: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESCompositeSetType_C", SNESCompositeSetType_Composite));
851: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESCompositeAddSNES_C", SNESCompositeAddSNES_Composite));
852: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESCompositeGetSNES_C", SNESCompositeGetSNES_Composite));
853: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESCompositeSetDamping_C", SNESCompositeSetDamping_Composite));
854: PetscFunctionReturn(PETSC_SUCCESS);
855: }