Actual source code: nasm.c
1: #include <petsc/private/snesimpl.h>
2: #include <petscdm.h>
4: typedef struct {
5: PetscInt n; /* local subdomains */
6: SNES *subsnes; /* nonlinear solvers for each subdomain */
7: Vec *x; /* solution vectors */
8: Vec *xl; /* solution local vectors */
9: Vec *y; /* step vectors */
10: Vec *b; /* rhs vectors */
11: Vec weight; /* weighting for adding updates on overlaps, in global space */
12: VecScatter *oscatter; /* scatter from global space to the subdomain global space */
13: VecScatter *oscatter_copy; /* copy of the above */
14: VecScatter *iscatter; /* scatter from global space to the nonoverlapping subdomain space */
15: VecScatter *gscatter; /* scatter from global space to the subdomain local space */
16: PCASMType type; /* ASM type */
17: PetscBool usesdm; /* use the DM for setting up the subproblems */
18: PetscBool finaljacobian; /* compute the jacobian of the converged solution */
19: PetscReal damping; /* damping parameter for updates from the blocks */
20: PetscBool weight_set; /* use a weight in the overlap updates */
22: /* logging events */
23: PetscLogEvent eventrestrictinterp;
24: PetscLogEvent eventsubsolve;
26: PetscInt fjtype; /* type of computed jacobian */
27: Vec xinit; /* initial solution in case the final jacobian type is computed as first */
28: } SNES_NASM;
30: const char *const SNESNASMTypes[] = {"NONE", "RESTRICT", "INTERPOLATE", "BASIC", "PCASMType", "PC_ASM_", NULL};
31: const char *const SNESNASMFJTypes[] = {"FINALOUTER", "FINALINNER", "INITIAL"};
33: static PetscErrorCode SNESReset_NASM(SNES snes)
34: {
35: SNES_NASM *nasm = (SNES_NASM *)snes->data;
36: PetscInt i;
38: PetscFunctionBegin;
39: for (i = 0; i < nasm->n; i++) {
40: if (nasm->xl) PetscCall(VecDestroy(&nasm->xl[i]));
41: if (nasm->x) PetscCall(VecDestroy(&nasm->x[i]));
42: if (nasm->y) PetscCall(VecDestroy(&nasm->y[i]));
43: if (nasm->b) PetscCall(VecDestroy(&nasm->b[i]));
45: if (nasm->subsnes) PetscCall(SNESDestroy(&nasm->subsnes[i]));
46: if (nasm->oscatter) PetscCall(VecScatterDestroy(&nasm->oscatter[i]));
47: if (nasm->oscatter_copy) PetscCall(VecScatterDestroy(&nasm->oscatter_copy[i]));
48: if (nasm->iscatter) PetscCall(VecScatterDestroy(&nasm->iscatter[i]));
49: if (nasm->gscatter) PetscCall(VecScatterDestroy(&nasm->gscatter[i]));
50: }
52: PetscCall(PetscFree(nasm->x));
53: PetscCall(PetscFree(nasm->xl));
54: PetscCall(PetscFree(nasm->y));
55: PetscCall(PetscFree(nasm->b));
57: if (nasm->xinit) PetscCall(VecDestroy(&nasm->xinit));
59: PetscCall(PetscFree(nasm->subsnes));
60: PetscCall(PetscFree(nasm->oscatter));
61: PetscCall(PetscFree(nasm->oscatter_copy));
62: PetscCall(PetscFree(nasm->iscatter));
63: PetscCall(PetscFree(nasm->gscatter));
65: if (nasm->weight_set) PetscCall(VecDestroy(&nasm->weight));
67: nasm->eventrestrictinterp = 0;
68: nasm->eventsubsolve = 0;
69: PetscFunctionReturn(PETSC_SUCCESS);
70: }
72: static PetscErrorCode SNESDestroy_NASM(SNES snes)
73: {
74: PetscFunctionBegin;
75: PetscCall(SNESReset_NASM(snes));
76: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetType_C", NULL));
77: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetType_C", NULL));
78: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetSubdomains_C", NULL));
79: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetSubdomains_C", NULL));
80: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetDamping_C", NULL));
81: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetDamping_C", NULL));
82: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetSubdomainVecs_C", NULL));
83: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetComputeFinalJacobian_C", NULL));
84: PetscCall(PetscFree(snes->data));
85: PetscFunctionReturn(PETSC_SUCCESS);
86: }
88: static PetscErrorCode DMGlobalToLocalSubDomainDirichletHook_Private(DM dm, Vec g, InsertMode mode, Vec l, void *ctx)
89: {
90: Vec bcs = (Vec)ctx;
92: PetscFunctionBegin;
93: PetscCall(VecCopy(bcs, l));
94: PetscFunctionReturn(PETSC_SUCCESS);
95: }
97: static PetscErrorCode SNESSetUp_NASM(SNES snes)
98: {
99: SNES_NASM *nasm = (SNES_NASM *)snes->data;
100: DM dm, subdm;
101: DM *subdms;
102: PetscInt i;
103: const char *optionsprefix;
104: Vec F;
105: PetscMPIInt size;
106: KSP ksp;
107: PC pc;
109: PetscFunctionBegin;
110: if (!nasm->subsnes) {
111: PetscCall(SNESGetDM(snes, &dm));
112: if (dm) {
113: nasm->usesdm = PETSC_TRUE;
114: PetscCall(DMCreateDomainDecomposition(dm, &nasm->n, NULL, NULL, NULL, &subdms));
115: PetscCheck(subdms, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "DM has no default decomposition defined. Set subsolves manually with SNESNASMSetSubdomains().");
116: PetscCall(DMCreateDomainDecompositionScatters(dm, nasm->n, subdms, &nasm->iscatter, &nasm->oscatter, &nasm->gscatter));
117: PetscCall(PetscMalloc1(nasm->n, &nasm->oscatter_copy));
118: for (i = 0; i < nasm->n; i++) PetscCall(VecScatterCopy(nasm->oscatter[i], &nasm->oscatter_copy[i]));
120: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
121: PetscCall(PetscMalloc1(nasm->n, &nasm->subsnes));
122: for (i = 0; i < nasm->n; i++) {
123: PetscCall(SNESCreate(PETSC_COMM_SELF, &nasm->subsnes[i]));
124: PetscCall(PetscObjectIncrementTabLevel((PetscObject)nasm->subsnes[i], (PetscObject)snes, 1));
125: PetscCall(SNESAppendOptionsPrefix(nasm->subsnes[i], optionsprefix));
126: PetscCall(SNESAppendOptionsPrefix(nasm->subsnes[i], "sub_"));
127: PetscCall(SNESSetDM(nasm->subsnes[i], subdms[i]));
128: PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)nasm->subsnes[i]), &size));
129: if (size == 1) {
130: PetscCall(SNESGetKSP(nasm->subsnes[i], &ksp));
131: PetscCall(KSPGetPC(ksp, &pc));
132: PetscCall(KSPSetType(ksp, KSPPREONLY));
133: PetscCall(PCSetType(pc, PCLU));
134: }
135: PetscCall(SNESSetFromOptions(nasm->subsnes[i]));
136: PetscCall(DMDestroy(&subdms[i]));
137: }
138: PetscCall(PetscFree(subdms));
139: } else SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "Cannot construct local problems automatically without a DM!");
140: } else SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "Must set subproblems manually if there is no DM!");
141: /* allocate the global vectors */
142: if (!nasm->x) PetscCall(PetscCalloc1(nasm->n, &nasm->x));
143: if (!nasm->xl) PetscCall(PetscCalloc1(nasm->n, &nasm->xl));
144: if (!nasm->y) PetscCall(PetscCalloc1(nasm->n, &nasm->y));
145: if (!nasm->b) PetscCall(PetscCalloc1(nasm->n, &nasm->b));
147: for (i = 0; i < nasm->n; i++) {
148: PetscCall(SNESGetFunction(nasm->subsnes[i], &F, NULL, NULL));
149: if (!nasm->x[i]) PetscCall(VecDuplicate(F, &nasm->x[i]));
150: if (!nasm->y[i]) PetscCall(VecDuplicate(F, &nasm->y[i]));
151: if (!nasm->b[i]) PetscCall(VecDuplicate(F, &nasm->b[i]));
152: if (!nasm->xl[i]) {
153: PetscCall(SNESGetDM(nasm->subsnes[i], &subdm));
154: PetscCall(DMCreateLocalVector(subdm, &nasm->xl[i]));
155: PetscCall(DMGlobalToLocalHookAdd(subdm, DMGlobalToLocalSubDomainDirichletHook_Private, NULL, nasm->xl[i]));
156: }
157: }
158: if (nasm->finaljacobian) {
159: PetscCall(SNESSetUpMatrices(snes));
160: if (nasm->fjtype == 2) PetscCall(VecDuplicate(snes->vec_sol, &nasm->xinit));
161: for (i = 0; i < nasm->n; i++) PetscCall(SNESSetUpMatrices(nasm->subsnes[i]));
162: }
163: PetscFunctionReturn(PETSC_SUCCESS);
164: }
166: static PetscErrorCode SNESSetFromOptions_NASM(SNES snes, PetscOptionItems *PetscOptionsObject)
167: {
168: PCASMType asmtype;
169: PetscBool flg, monflg;
170: SNES_NASM *nasm = (SNES_NASM *)snes->data;
172: PetscFunctionBegin;
173: PetscOptionsHeadBegin(PetscOptionsObject, "Nonlinear Additive Schwarz options");
174: PetscCall(PetscOptionsEnum("-snes_nasm_type", "Type of restriction/extension", "", SNESNASMTypes, (PetscEnum)nasm->type, (PetscEnum *)&asmtype, &flg));
175: if (flg) PetscCall(SNESNASMSetType(snes, asmtype));
176: flg = PETSC_FALSE;
177: monflg = PETSC_TRUE;
178: PetscCall(PetscOptionsReal("-snes_nasm_damping", "The new solution is obtained as old solution plus dmp times (sum of the solutions on the subdomains)", "SNESNASMSetDamping", nasm->damping, &nasm->damping, &flg));
179: if (flg) PetscCall(SNESNASMSetDamping(snes, nasm->damping));
180: PetscCall(PetscOptionsDeprecated("-snes_nasm_sub_view", NULL, "3.15", "Use -snes_view ::ascii_info_detail"));
181: PetscCall(PetscOptionsBool("-snes_nasm_finaljacobian", "Compute the global jacobian of the final iterate (for ASPIN)", "", nasm->finaljacobian, &nasm->finaljacobian, NULL));
182: PetscCall(PetscOptionsEList("-snes_nasm_finaljacobian_type", "The type of the final jacobian computed.", "", SNESNASMFJTypes, 3, SNESNASMFJTypes[0], &nasm->fjtype, NULL));
183: PetscCall(PetscOptionsBool("-snes_nasm_log", "Log times for subSNES solves and restriction", "", monflg, &monflg, &flg));
184: if (flg) {
185: PetscCall(PetscLogEventRegister("SNESNASMSubSolve", ((PetscObject)snes)->classid, &nasm->eventsubsolve));
186: PetscCall(PetscLogEventRegister("SNESNASMRestrict", ((PetscObject)snes)->classid, &nasm->eventrestrictinterp));
187: }
188: PetscOptionsHeadEnd();
189: PetscFunctionReturn(PETSC_SUCCESS);
190: }
192: static PetscErrorCode SNESView_NASM(SNES snes, PetscViewer viewer)
193: {
194: SNES_NASM *nasm = (SNES_NASM *)snes->data;
195: PetscMPIInt rank, size;
196: PetscInt i, N, bsz;
197: PetscBool iascii, isstring;
198: PetscViewer sviewer;
199: MPI_Comm comm;
200: PetscViewerFormat format;
201: const char *prefix;
203: PetscFunctionBegin;
204: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
205: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
206: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
207: PetscCallMPI(MPI_Comm_rank(comm, &rank));
208: PetscCallMPI(MPI_Comm_size(comm, &size));
209: PetscCall(MPIU_Allreduce(&nasm->n, &N, 1, MPIU_INT, MPI_SUM, comm));
210: if (iascii) {
211: PetscCall(PetscViewerASCIIPrintf(viewer, " total subdomain blocks = %" PetscInt_FMT "\n", N));
212: PetscCall(PetscViewerGetFormat(viewer, &format));
213: if (format != PETSC_VIEWER_ASCII_INFO_DETAIL) {
214: if (nasm->subsnes) {
215: PetscCall(PetscViewerASCIIPrintf(viewer, " Local solver information for first block on rank 0:\n"));
216: PetscCall(SNESGetOptionsPrefix(snes, &prefix));
217: PetscCall(PetscViewerASCIIPrintf(viewer, " Use -%ssnes_view ::ascii_info_detail to display information for all blocks\n", prefix ? prefix : ""));
218: PetscCall(PetscViewerASCIIPushTab(viewer));
219: PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
220: if (rank == 0) {
221: PetscCall(PetscViewerASCIIPushTab(viewer));
222: PetscCall(SNESView(nasm->subsnes[0], sviewer));
223: PetscCall(PetscViewerASCIIPopTab(viewer));
224: }
225: PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
226: PetscCall(PetscViewerASCIIPopTab(viewer));
227: }
228: } else {
229: /* print the solver on each block */
230: PetscCall(PetscViewerASCIIPushSynchronized(viewer));
231: PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, " [%d] number of local blocks = %" PetscInt_FMT "\n", (int)rank, nasm->n));
232: PetscCall(PetscViewerFlush(viewer));
233: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
234: PetscCall(PetscViewerASCIIPrintf(viewer, " Local solver information for each block is in the following SNES objects:\n"));
235: PetscCall(PetscViewerASCIIPushTab(viewer));
236: PetscCall(PetscViewerASCIIPrintf(viewer, "- - - - - - - - - - - - - - - - - -\n"));
237: PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
238: for (i = 0; i < nasm->n; i++) {
239: PetscCall(VecGetLocalSize(nasm->x[i], &bsz));
240: PetscCall(PetscViewerASCIIPrintf(sviewer, "[%d] local block number %" PetscInt_FMT ", size = %" PetscInt_FMT "\n", (int)rank, i, bsz));
241: PetscCall(SNESView(nasm->subsnes[i], sviewer));
242: PetscCall(PetscViewerASCIIPrintf(sviewer, "- - - - - - - - - - - - - - - - - -\n"));
243: }
244: PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
245: PetscCall(PetscViewerFlush(viewer));
246: PetscCall(PetscViewerASCIIPopTab(viewer));
247: }
248: } else if (isstring) {
249: PetscCall(PetscViewerStringSPrintf(viewer, " blocks=%" PetscInt_FMT ",type=%s", N, SNESNASMTypes[nasm->type]));
250: PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
251: if (nasm->subsnes && rank == 0) PetscCall(SNESView(nasm->subsnes[0], sviewer));
252: PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
253: }
254: PetscFunctionReturn(PETSC_SUCCESS);
255: }
257: /*@
258: SNESNASMSetType - Set the type of subdomain update used for the nonlinear additive Schwarz solver
260: Logically Collective
262: Input Parameters:
263: + snes - the `SNES` context
264: - type - the type of update, `PC_ASM_BASIC` or `PC_ASM_RESTRICT`
266: Level: intermediate
268: .seealso: `SNESNASM`, `SNESNASMGetType()`, `PCASMSetType()`, `PC_ASM_BASIC`, `PC_ASM_RESTRICT`, `PCASMType`
269: @*/
270: PetscErrorCode SNESNASMSetType(SNES snes, PCASMType type)
271: {
272: PetscErrorCode (*f)(SNES, PCASMType);
274: PetscFunctionBegin;
275: PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMSetType_C", &f));
276: if (f) PetscCall((f)(snes, type));
277: PetscFunctionReturn(PETSC_SUCCESS);
278: }
280: static PetscErrorCode SNESNASMSetType_NASM(SNES snes, PCASMType type)
281: {
282: SNES_NASM *nasm = (SNES_NASM *)snes->data;
284: PetscFunctionBegin;
285: PetscCheck(type == PC_ASM_BASIC || type == PC_ASM_RESTRICT, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "SNESNASM only supports basic and restrict types");
286: nasm->type = type;
287: PetscFunctionReturn(PETSC_SUCCESS);
288: }
290: /*@
291: SNESNASMGetType - Get the type of subdomain update used for the nonlinear additive Schwarz solver
293: Logically Collective
295: Input Parameter:
296: . snes - the `SNES` context
298: Output Parameter:
299: . type - the type of update
301: Level: intermediate
303: .seealso: `SNESNASM`, `SNESNASMSetType()`, `PCASMGetType()`, `PC_ASM_BASIC`, `PC_ASM_RESTRICT`, `PCASMType`
304: @*/
305: PetscErrorCode SNESNASMGetType(SNES snes, PCASMType *type)
306: {
307: PetscFunctionBegin;
308: PetscUseMethod(snes, "SNESNASMGetType_C", (SNES, PCASMType *), (snes, type));
309: PetscFunctionReturn(PETSC_SUCCESS);
310: }
312: static PetscErrorCode SNESNASMGetType_NASM(SNES snes, PCASMType *type)
313: {
314: SNES_NASM *nasm = (SNES_NASM *)snes->data;
316: PetscFunctionBegin;
317: *type = nasm->type;
318: PetscFunctionReturn(PETSC_SUCCESS);
319: }
321: /*@
322: SNESNASMSetSubdomains - Manually Set the context required to restrict and solve subdomain problems in the nonlinear additive Schwarz solver
324: Logically Collective
326: Input Parameters:
327: + snes - the SNES context
328: . n - the number of local subdomains
329: . subsnes - solvers defined on the local subdomains
330: . iscatter - scatters into the nonoverlapping portions of the local subdomains
331: . oscatter - scatters into the overlapping portions of the local subdomains
332: - gscatter - scatters into the (ghosted) local vector of the local subdomain
334: Level: intermediate
336: .seealso: `SNESNASM`, `SNESNASMGetSubdomains()`
337: @*/
338: PetscErrorCode SNESNASMSetSubdomains(SNES snes, PetscInt n, SNES subsnes[], VecScatter iscatter[], VecScatter oscatter[], VecScatter gscatter[])
339: {
340: PetscErrorCode (*f)(SNES, PetscInt, SNES *, VecScatter *, VecScatter *, VecScatter *);
342: PetscFunctionBegin;
343: PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMSetSubdomains_C", &f));
344: if (f) PetscCall((f)(snes, n, subsnes, iscatter, oscatter, gscatter));
345: PetscFunctionReturn(PETSC_SUCCESS);
346: }
348: static PetscErrorCode SNESNASMSetSubdomains_NASM(SNES snes, PetscInt n, SNES subsnes[], VecScatter iscatter[], VecScatter oscatter[], VecScatter gscatter[])
349: {
350: PetscInt i;
351: SNES_NASM *nasm = (SNES_NASM *)snes->data;
353: PetscFunctionBegin;
354: PetscCheck(!snes->setupcalled, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "SNESNASMSetSubdomains() should be called before calling SNESSetUp().");
356: /* tear down the previously set things */
357: PetscCall(SNESReset(snes));
359: nasm->n = n;
360: if (oscatter) {
361: for (i = 0; i < n; i++) PetscCall(PetscObjectReference((PetscObject)oscatter[i]));
362: }
363: if (iscatter) {
364: for (i = 0; i < n; i++) PetscCall(PetscObjectReference((PetscObject)iscatter[i]));
365: }
366: if (gscatter) {
367: for (i = 0; i < n; i++) PetscCall(PetscObjectReference((PetscObject)gscatter[i]));
368: }
369: if (oscatter) {
370: PetscCall(PetscMalloc1(n, &nasm->oscatter));
371: PetscCall(PetscMalloc1(n, &nasm->oscatter_copy));
372: for (i = 0; i < n; i++) {
373: nasm->oscatter[i] = oscatter[i];
374: PetscCall(VecScatterCopy(oscatter[i], &nasm->oscatter_copy[i]));
375: }
376: }
377: if (iscatter) {
378: PetscCall(PetscMalloc1(n, &nasm->iscatter));
379: for (i = 0; i < n; i++) nasm->iscatter[i] = iscatter[i];
380: }
381: if (gscatter) {
382: PetscCall(PetscMalloc1(n, &nasm->gscatter));
383: for (i = 0; i < n; i++) nasm->gscatter[i] = gscatter[i];
384: }
386: if (subsnes) {
387: PetscCall(PetscMalloc1(n, &nasm->subsnes));
388: for (i = 0; i < n; i++) nasm->subsnes[i] = subsnes[i];
389: }
390: PetscFunctionReturn(PETSC_SUCCESS);
391: }
393: /*@
394: SNESNASMGetSubdomains - Get the local subdomain contexts for the nonlinear additive Schwarz solver
396: Not Collective but some of the objects returned will be parallel
398: Input Parameter:
399: . snes - the `SNES` context
401: Output Parameters:
402: + n - the number of local subdomains
403: . subsnes - solvers defined on the local subdomains
404: . iscatter - scatters into the nonoverlapping portions of the local subdomains
405: . oscatter - scatters into the overlapping portions of the local subdomains
406: - gscatter - scatters into the (ghosted) local vector of the local subdomain
408: Level: intermediate
410: .seealso: `SNESNASM`, `SNESNASMSetSubdomains()`
411: @*/
412: PetscErrorCode SNESNASMGetSubdomains(SNES snes, PetscInt *n, SNES *subsnes[], VecScatter *iscatter[], VecScatter *oscatter[], VecScatter *gscatter[])
413: {
414: PetscErrorCode (*f)(SNES, PetscInt *, SNES **, VecScatter **, VecScatter **, VecScatter **);
416: PetscFunctionBegin;
417: PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMGetSubdomains_C", &f));
418: if (f) PetscCall((f)(snes, n, subsnes, iscatter, oscatter, gscatter));
419: PetscFunctionReturn(PETSC_SUCCESS);
420: }
422: static PetscErrorCode SNESNASMGetSubdomains_NASM(SNES snes, PetscInt *n, SNES *subsnes[], VecScatter *iscatter[], VecScatter *oscatter[], VecScatter *gscatter[])
423: {
424: SNES_NASM *nasm = (SNES_NASM *)snes->data;
426: PetscFunctionBegin;
427: if (n) *n = nasm->n;
428: if (oscatter) *oscatter = nasm->oscatter;
429: if (iscatter) *iscatter = nasm->iscatter;
430: if (gscatter) *gscatter = nasm->gscatter;
431: if (subsnes) *subsnes = nasm->subsnes;
432: PetscFunctionReturn(PETSC_SUCCESS);
433: }
435: /*@
436: SNESNASMGetSubdomainVecs - Get the processor-local subdomain vectors for the nonlinear additive Schwarz solver
438: Not Collective
440: Input Parameter:
441: . snes - the `SNES` context
443: Output Parameters:
444: + n - the number of local subdomains
445: . x - The subdomain solution vector
446: . y - The subdomain step vector
447: . b - The subdomain RHS vector
448: - xl - The subdomain local vectors (ghosted)
450: Level: developer
452: .seealso: `SNESNASM`, `SNESNASMGetSubdomains()`
453: @*/
454: PetscErrorCode SNESNASMGetSubdomainVecs(SNES snes, PetscInt *n, Vec **x, Vec **y, Vec **b, Vec **xl)
455: {
456: PetscErrorCode (*f)(SNES, PetscInt *, Vec **, Vec **, Vec **, Vec **);
458: PetscFunctionBegin;
459: PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMGetSubdomainVecs_C", &f));
460: if (f) PetscCall((f)(snes, n, x, y, b, xl));
461: PetscFunctionReturn(PETSC_SUCCESS);
462: }
464: static PetscErrorCode SNESNASMGetSubdomainVecs_NASM(SNES snes, PetscInt *n, Vec **x, Vec **y, Vec **b, Vec **xl)
465: {
466: SNES_NASM *nasm = (SNES_NASM *)snes->data;
468: PetscFunctionBegin;
469: if (n) *n = nasm->n;
470: if (x) *x = nasm->x;
471: if (y) *y = nasm->y;
472: if (b) *b = nasm->b;
473: if (xl) *xl = nasm->xl;
474: PetscFunctionReturn(PETSC_SUCCESS);
475: }
477: /*@
478: SNESNASMSetComputeFinalJacobian - Schedules the computation of the global and subdomain Jacobians upon convergence for the
479: nonlinear additive Schwarz solver
481: Collective
483: Input Parameters:
484: + snes - the SNES context
485: - flg - `PETSC_TRUE` to compute the Jacobians
487: Level: developer
489: Notes:
490: This is used almost exclusively in the implementation of `SNESASPIN`, where the converged subdomain and global Jacobian
491: is needed at each linear iteration.
493: .seealso: `SNESNASM`, `SNESNASMGetSubdomains()`
494: @*/
495: PetscErrorCode SNESNASMSetComputeFinalJacobian(SNES snes, PetscBool flg)
496: {
497: PetscErrorCode (*f)(SNES, PetscBool);
499: PetscFunctionBegin;
500: PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMSetComputeFinalJacobian_C", &f));
501: if (f) PetscCall((f)(snes, flg));
502: PetscFunctionReturn(PETSC_SUCCESS);
503: }
505: static PetscErrorCode SNESNASMSetComputeFinalJacobian_NASM(SNES snes, PetscBool flg)
506: {
507: SNES_NASM *nasm = (SNES_NASM *)snes->data;
509: PetscFunctionBegin;
510: nasm->finaljacobian = flg;
511: PetscFunctionReturn(PETSC_SUCCESS);
512: }
514: /*@
515: SNESNASMSetDamping - Sets the update damping for `SNESNASM` the nonlinear additive Schwarz solver
517: Logically Collective
519: Input Parameters:
520: + snes - the `SNES` context
521: - dmp - damping
523: Level: intermediate
525: Notes:
526: The new solution is obtained as old solution plus dmp times (sum of the solutions on the subdomains)
528: .seealso: `SNESNASM`, `SNESNASMGetDamping()`
529: @*/
530: PetscErrorCode SNESNASMSetDamping(SNES snes, PetscReal dmp)
531: {
532: PetscErrorCode (*f)(SNES, PetscReal);
534: PetscFunctionBegin;
535: PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMSetDamping_C", (void (**)(void)) & f));
536: if (f) PetscCall((f)(snes, dmp));
537: PetscFunctionReturn(PETSC_SUCCESS);
538: }
540: static PetscErrorCode SNESNASMSetDamping_NASM(SNES snes, PetscReal dmp)
541: {
542: SNES_NASM *nasm = (SNES_NASM *)snes->data;
544: PetscFunctionBegin;
545: nasm->damping = dmp;
546: PetscFunctionReturn(PETSC_SUCCESS);
547: }
549: /*@
550: SNESNASMGetDamping - Gets the update damping for `SNESNASM` the nonlinear additive Schwarz solver
552: Not Collective
554: Input Parameter:
555: . snes - the SNES context
557: Output Parameter:
558: . dmp - damping
560: Level: intermediate
562: .seealso: `SNESNASM`, `SNESNASMSetDamping()`
563: @*/
564: PetscErrorCode SNESNASMGetDamping(SNES snes, PetscReal *dmp)
565: {
566: PetscFunctionBegin;
567: PetscUseMethod(snes, "SNESNASMGetDamping_C", (SNES, PetscReal *), (snes, dmp));
568: PetscFunctionReturn(PETSC_SUCCESS);
569: }
571: static PetscErrorCode SNESNASMGetDamping_NASM(SNES snes, PetscReal *dmp)
572: {
573: SNES_NASM *nasm = (SNES_NASM *)snes->data;
575: PetscFunctionBegin;
576: *dmp = nasm->damping;
577: PetscFunctionReturn(PETSC_SUCCESS);
578: }
580: /*
581: Input Parameters:
582: + snes - The solver
583: . B - The RHS vector
584: - X - The initial guess
586: Output Parameter:
587: . Y - The solution update
589: TODO: All scatters should be packed into one
590: */
591: PetscErrorCode SNESNASMSolveLocal_Private(SNES snes, Vec B, Vec Y, Vec X)
592: {
593: SNES_NASM *nasm = (SNES_NASM *)snes->data;
594: SNES subsnes;
595: PetscInt i;
596: PetscReal dmp;
597: Vec Xl, Bl, Yl, Xlloc;
598: VecScatter iscat, oscat, gscat, oscat_copy;
599: DM dm, subdm;
600: PCASMType type;
602: PetscFunctionBegin;
603: PetscCall(SNESNASMGetType(snes, &type));
604: PetscCall(SNESGetDM(snes, &dm));
605: PetscCall(VecSet(Y, 0));
606: if (nasm->eventrestrictinterp) PetscCall(PetscLogEventBegin(nasm->eventrestrictinterp, snes, 0, 0, 0));
607: for (i = 0; i < nasm->n; i++) {
608: /* scatter the solution to the global solution and the local solution */
609: Xl = nasm->x[i];
610: Xlloc = nasm->xl[i];
611: oscat = nasm->oscatter[i];
612: oscat_copy = nasm->oscatter_copy[i];
613: gscat = nasm->gscatter[i];
614: PetscCall(VecScatterBegin(oscat, X, Xl, INSERT_VALUES, SCATTER_FORWARD));
615: PetscCall(VecScatterBegin(gscat, X, Xlloc, INSERT_VALUES, SCATTER_FORWARD));
616: if (B) {
617: /* scatter the RHS to the local RHS */
618: Bl = nasm->b[i];
619: PetscCall(VecScatterBegin(oscat_copy, B, Bl, INSERT_VALUES, SCATTER_FORWARD));
620: }
621: }
622: if (nasm->eventrestrictinterp) PetscCall(PetscLogEventEnd(nasm->eventrestrictinterp, snes, 0, 0, 0));
624: if (nasm->eventsubsolve) PetscCall(PetscLogEventBegin(nasm->eventsubsolve, snes, 0, 0, 0));
625: for (i = 0; i < nasm->n; i++) {
626: Xl = nasm->x[i];
627: Xlloc = nasm->xl[i];
628: Yl = nasm->y[i];
629: subsnes = nasm->subsnes[i];
630: PetscCall(SNESGetDM(subsnes, &subdm));
631: iscat = nasm->iscatter[i];
632: oscat = nasm->oscatter[i];
633: oscat_copy = nasm->oscatter_copy[i];
634: gscat = nasm->gscatter[i];
635: PetscCall(VecScatterEnd(oscat, X, Xl, INSERT_VALUES, SCATTER_FORWARD));
636: PetscCall(VecScatterEnd(gscat, X, Xlloc, INSERT_VALUES, SCATTER_FORWARD));
637: if (B) {
638: Bl = nasm->b[i];
639: PetscCall(VecScatterEnd(oscat_copy, B, Bl, INSERT_VALUES, SCATTER_FORWARD));
640: } else Bl = NULL;
642: PetscCall(DMSubDomainRestrict(dm, oscat, gscat, subdm));
643: PetscCall(VecCopy(Xl, Yl));
644: PetscCall(SNESSolve(subsnes, Bl, Xl));
645: PetscCall(VecAYPX(Yl, -1.0, Xl));
646: PetscCall(VecScale(Yl, nasm->damping));
647: if (type == PC_ASM_BASIC) {
648: PetscCall(VecScatterBegin(oscat, Yl, Y, ADD_VALUES, SCATTER_REVERSE));
649: PetscCall(VecScatterEnd(oscat, Yl, Y, ADD_VALUES, SCATTER_REVERSE));
650: } else if (type == PC_ASM_RESTRICT) {
651: PetscCall(VecScatterBegin(iscat, Yl, Y, ADD_VALUES, SCATTER_REVERSE));
652: PetscCall(VecScatterEnd(iscat, Yl, Y, ADD_VALUES, SCATTER_REVERSE));
653: } else SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "Only basic and restrict types are supported for SNESNASM");
654: }
655: if (nasm->eventsubsolve) PetscCall(PetscLogEventEnd(nasm->eventsubsolve, snes, 0, 0, 0));
656: if (nasm->eventrestrictinterp) PetscCall(PetscLogEventBegin(nasm->eventrestrictinterp, snes, 0, 0, 0));
657: if (nasm->weight_set) PetscCall(VecPointwiseMult(Y, Y, nasm->weight));
658: if (nasm->eventrestrictinterp) PetscCall(PetscLogEventEnd(nasm->eventrestrictinterp, snes, 0, 0, 0));
659: PetscCall(SNESNASMGetDamping(snes, &dmp));
660: PetscCall(VecAXPY(X, dmp, Y));
661: PetscFunctionReturn(PETSC_SUCCESS);
662: }
664: static PetscErrorCode SNESNASMComputeFinalJacobian_Private(SNES snes, Vec Xfinal)
665: {
666: Vec X = Xfinal;
667: SNES_NASM *nasm = (SNES_NASM *)snes->data;
668: SNES subsnes;
669: PetscInt i, lag = 1;
670: Vec Xlloc, Xl, Fl, F;
671: VecScatter oscat, gscat;
672: DM dm, subdm;
674: PetscFunctionBegin;
675: if (nasm->fjtype == 2) X = nasm->xinit;
676: F = snes->vec_func;
677: if (snes->normschedule == SNES_NORM_NONE) PetscCall(SNESComputeFunction(snes, X, F));
678: PetscCall(SNESComputeJacobian(snes, X, snes->jacobian, snes->jacobian_pre));
679: PetscCall(SNESGetDM(snes, &dm));
680: if (nasm->eventrestrictinterp) PetscCall(PetscLogEventBegin(nasm->eventrestrictinterp, snes, 0, 0, 0));
681: if (nasm->fjtype != 1) {
682: for (i = 0; i < nasm->n; i++) {
683: Xlloc = nasm->xl[i];
684: gscat = nasm->gscatter[i];
685: PetscCall(VecScatterBegin(gscat, X, Xlloc, INSERT_VALUES, SCATTER_FORWARD));
686: }
687: }
688: if (nasm->eventrestrictinterp) PetscCall(PetscLogEventEnd(nasm->eventrestrictinterp, snes, 0, 0, 0));
689: for (i = 0; i < nasm->n; i++) {
690: Fl = nasm->subsnes[i]->vec_func;
691: Xl = nasm->x[i];
692: Xlloc = nasm->xl[i];
693: subsnes = nasm->subsnes[i];
694: oscat = nasm->oscatter[i];
695: gscat = nasm->gscatter[i];
696: if (nasm->fjtype != 1) PetscCall(VecScatterEnd(gscat, X, Xlloc, INSERT_VALUES, SCATTER_FORWARD));
697: PetscCall(SNESGetDM(subsnes, &subdm));
698: PetscCall(DMSubDomainRestrict(dm, oscat, gscat, subdm));
699: if (nasm->fjtype != 1) {
700: PetscCall(DMLocalToGlobalBegin(subdm, Xlloc, INSERT_VALUES, Xl));
701: PetscCall(DMLocalToGlobalEnd(subdm, Xlloc, INSERT_VALUES, Xl));
702: }
703: if (subsnes->lagjacobian == -1) subsnes->lagjacobian = -2;
704: else if (subsnes->lagjacobian > 1) lag = subsnes->lagjacobian;
705: PetscCall(SNESComputeFunction(subsnes, Xl, Fl));
706: PetscCall(SNESComputeJacobian(subsnes, Xl, subsnes->jacobian, subsnes->jacobian_pre));
707: if (lag > 1) subsnes->lagjacobian = lag;
708: }
709: PetscFunctionReturn(PETSC_SUCCESS);
710: }
712: static PetscErrorCode SNESSolve_NASM(SNES snes)
713: {
714: Vec F;
715: Vec X;
716: Vec B;
717: Vec Y;
718: PetscInt i;
719: PetscReal fnorm = 0.0;
720: SNESNormSchedule normschedule;
721: SNES_NASM *nasm = (SNES_NASM *)snes->data;
723: PetscFunctionBegin;
725: PetscCheck(!snes->xl & !snes->xu && !snes->ops->computevariablebounds, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "SNES solver %s does not support bounds", ((PetscObject)snes)->type_name);
727: PetscCall(PetscCitationsRegister(SNESCitation, &SNEScite));
728: X = snes->vec_sol;
729: Y = snes->vec_sol_update;
730: F = snes->vec_func;
731: B = snes->vec_rhs;
733: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
734: snes->iter = 0;
735: snes->norm = 0.;
736: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
737: snes->reason = SNES_CONVERGED_ITERATING;
738: PetscCall(SNESGetNormSchedule(snes, &normschedule));
739: if (normschedule == SNES_NORM_ALWAYS || normschedule == SNES_NORM_INITIAL_ONLY || normschedule == SNES_NORM_INITIAL_FINAL_ONLY) {
740: /* compute the initial function and preconditioned update delX */
741: if (!snes->vec_func_init_set) {
742: PetscCall(SNESComputeFunction(snes, X, F));
743: } else snes->vec_func_init_set = PETSC_FALSE;
745: PetscCall(VecNorm(F, NORM_2, &fnorm)); /* fnorm <- ||F|| */
746: SNESCheckFunctionNorm(snes, fnorm);
747: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
748: snes->iter = 0;
749: snes->norm = fnorm;
750: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
751: PetscCall(SNESLogConvergenceHistory(snes, snes->norm, 0));
752: PetscCall(SNESMonitor(snes, 0, snes->norm));
754: /* test convergence */
755: PetscUseTypeMethod(snes, converged, 0, 0.0, 0.0, fnorm, &snes->reason, snes->cnvP);
756: if (snes->reason) PetscFunctionReturn(PETSC_SUCCESS);
757: } else {
758: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
759: PetscCall(SNESLogConvergenceHistory(snes, snes->norm, 0));
760: PetscCall(SNESMonitor(snes, 0, snes->norm));
761: }
763: /* Call general purpose update function */
764: PetscTryTypeMethod(snes, update, snes->iter);
765: /* copy the initial solution over for later */
766: if (nasm->fjtype == 2) PetscCall(VecCopy(X, nasm->xinit));
768: for (i = 0; i < snes->max_its; i++) {
769: PetscCall(SNESNASMSolveLocal_Private(snes, B, Y, X));
770: if (normschedule == SNES_NORM_ALWAYS || ((i == snes->max_its - 1) && (normschedule == SNES_NORM_INITIAL_FINAL_ONLY || normschedule == SNES_NORM_FINAL_ONLY))) {
771: PetscCall(SNESComputeFunction(snes, X, F));
772: PetscCall(VecNorm(F, NORM_2, &fnorm)); /* fnorm <- ||F|| */
773: SNESCheckFunctionNorm(snes, fnorm);
774: }
775: /* Monitor convergence */
776: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
777: snes->iter = i + 1;
778: snes->norm = fnorm;
779: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
780: PetscCall(SNESLogConvergenceHistory(snes, snes->norm, 0));
781: PetscCall(SNESMonitor(snes, snes->iter, snes->norm));
782: /* Test for convergence */
783: if (normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, snes->iter, 0.0, 0.0, fnorm, &snes->reason, snes->cnvP);
784: if (snes->reason) break;
785: /* Call general purpose update function */
786: PetscTryTypeMethod(snes, update, snes->iter);
787: }
788: if (nasm->finaljacobian) {
789: PetscCall(SNESNASMComputeFinalJacobian_Private(snes, X));
790: SNESCheckJacobianDomainerror(snes);
791: }
792: if (normschedule == SNES_NORM_ALWAYS) {
793: if (i == snes->max_its) {
794: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
795: if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
796: }
797: } else if (!snes->reason) snes->reason = SNES_CONVERGED_ITS; /* NASM is meant to be used as a nonlinear preconditioner */
798: PetscFunctionReturn(PETSC_SUCCESS);
799: }
801: /*MC
802: SNESNASM - Nonlinear Additive Schwarz solver
804: Options Database Keys:
805: + -snes_nasm_log - enable logging events for the communication and solve stages
806: . -snes_nasm_type <basic,restrict> - type of subdomain update used
807: . -snes_asm_damping <dmp> - the new solution is obtained as old solution plus dmp times (sum of the solutions on the subdomains)
808: . -snes_nasm_finaljacobian - compute the local and global jacobians of the final iterate
809: . -snes_nasm_finaljacobian_type <finalinner,finalouter,initial> - pick state the jacobian is calculated at
810: . -sub_snes_ - options prefix of the subdomain nonlinear solves
811: . -sub_ksp_ - options prefix of the subdomain Krylov solver
812: - -sub_pc_ - options prefix of the subdomain preconditioner
814: Level: advanced
816: Note:
817: This is not often used directly as a solver, it converges too slowly. However it works well as a nonlinear preconditioner for
818: the `SNESASPIN` solver
820: Developer Note:
821: This is a non-Newton based nonlinear solver that does not directly require a Jacobian; hence the flag snes->usesksp is set to
822: false and `SNESView()` and -snes_view do not display a `KSP` object. However, if the flag nasm->finaljacobian is set (for example, if
823: `SNESNASM` is used as a nonlinear preconditioner for `SNESASPIN`) then `SNESSetUpMatrices()` is called to generate the
824: Jacobian (needed by `SNESASPIN`)
825: and this utilizes the inner `KSP` object for storing the matrices, but the `KSP` is never used for solving a linear system. When `SNESNASM` is
826: used by `SNESASPIN` they share the same Jacobian matrices because `SNESSetUp()` (called on the outer `SNESASPIN`) causes the inner `SNES`
827: object (in this case `SNESNASM`) to inherit the outer Jacobian matrices.
829: References:
830: . * - Peter R. Brune, Matthew G. Knepley, Barry F. Smith, and Xuemin Tu, "Composing Scalable Nonlinear Algebraic Solvers",
831: SIAM Review, 57(4), 2015
833: .seealso: `SNESCreate()`, `SNES`, `SNESSetType()`, `SNESType`, `SNESNASMSetType()`, `SNESNASMGetType()`, `SNESNASMSetSubdomains()`, `SNESNASMGetSubdomains()`, `SNESNASMGetSubdomainVecs()`, `SNESNASMSetComputeFinalJacobian()`, `SNESNASMSetDamping()`, `SNESNASMGetDamping()`
834: M*/
836: PETSC_EXTERN PetscErrorCode SNESCreate_NASM(SNES snes)
837: {
838: SNES_NASM *nasm;
840: PetscFunctionBegin;
841: PetscCall(PetscNew(&nasm));
842: snes->data = (void *)nasm;
844: nasm->n = PETSC_DECIDE;
845: nasm->subsnes = NULL;
846: nasm->x = NULL;
847: nasm->xl = NULL;
848: nasm->y = NULL;
849: nasm->b = NULL;
850: nasm->oscatter = NULL;
851: nasm->oscatter_copy = NULL;
852: nasm->iscatter = NULL;
853: nasm->gscatter = NULL;
854: nasm->damping = 1.;
856: nasm->type = PC_ASM_BASIC;
857: nasm->finaljacobian = PETSC_FALSE;
858: nasm->weight_set = PETSC_FALSE;
860: snes->ops->destroy = SNESDestroy_NASM;
861: snes->ops->setup = SNESSetUp_NASM;
862: snes->ops->setfromoptions = SNESSetFromOptions_NASM;
863: snes->ops->view = SNESView_NASM;
864: snes->ops->solve = SNESSolve_NASM;
865: snes->ops->reset = SNESReset_NASM;
867: snes->usesksp = PETSC_FALSE;
868: snes->usesnpc = PETSC_FALSE;
870: snes->alwayscomputesfinalresidual = PETSC_FALSE;
872: nasm->fjtype = 0;
873: nasm->xinit = NULL;
874: nasm->eventrestrictinterp = 0;
875: nasm->eventsubsolve = 0;
877: if (!snes->tolerancesset) {
878: snes->max_its = 10000;
879: snes->max_funcs = 10000;
880: }
882: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetType_C", SNESNASMSetType_NASM));
883: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetType_C", SNESNASMGetType_NASM));
884: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetSubdomains_C", SNESNASMSetSubdomains_NASM));
885: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetSubdomains_C", SNESNASMGetSubdomains_NASM));
886: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetDamping_C", SNESNASMSetDamping_NASM));
887: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetDamping_C", SNESNASMGetDamping_NASM));
888: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetSubdomainVecs_C", SNESNASMGetSubdomainVecs_NASM));
889: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetComputeFinalJacobian_C", SNESNASMSetComputeFinalJacobian_NASM));
890: PetscFunctionReturn(PETSC_SUCCESS);
891: }
893: /*@
894: SNESNASMGetSNES - Gets a subsolver
896: Not Collective
898: Input Parameters:
899: + snes - the `SNES` context
900: - i - the number of the subsnes to get
902: Output Parameter:
903: . subsnes - the subsolver context
905: Level: intermediate
907: .seealso: `SNESNASM`, `SNESNASMGetNumber()`
908: @*/
909: PetscErrorCode SNESNASMGetSNES(SNES snes, PetscInt i, SNES *subsnes)
910: {
911: SNES_NASM *nasm = (SNES_NASM *)snes->data;
913: PetscFunctionBegin;
914: PetscCheck(i >= 0 && i < nasm->n, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "No such subsolver");
915: *subsnes = nasm->subsnes[i];
916: PetscFunctionReturn(PETSC_SUCCESS);
917: }
919: /*@
920: SNESNASMGetNumber - Gets number of subsolvers
922: Not Collective
924: Input Parameter:
925: . snes - the `SNES` context
927: Output Parameter:
928: . n - the number of subsolvers
930: Level: intermediate
932: .seealso: `SNESNASM`, `SNESNASMGetSNES()`
933: @*/
934: PetscErrorCode SNESNASMGetNumber(SNES snes, PetscInt *n)
935: {
936: SNES_NASM *nasm = (SNES_NASM *)snes->data;
938: PetscFunctionBegin;
939: *n = nasm->n;
940: PetscFunctionReturn(PETSC_SUCCESS);
941: }
943: /*@
944: SNESNASMSetWeight - Sets weight to use when adding overlapping updates
946: Collective
948: Input Parameters:
949: + snes - the `SNES` context
950: - weight - the weights to use (typically 1/N for each dof, where N is the number of patches it appears in)
952: Level: intermediate
954: .seealso: `SNESNASM`
955: @*/
956: PetscErrorCode SNESNASMSetWeight(SNES snes, Vec weight)
957: {
958: SNES_NASM *nasm = (SNES_NASM *)snes->data;
960: PetscFunctionBegin;
962: PetscCall(VecDestroy(&nasm->weight));
963: nasm->weight_set = PETSC_TRUE;
964: nasm->weight = weight;
965: PetscCall(PetscObjectReference((PetscObject)nasm->weight));
967: PetscFunctionReturn(PETSC_SUCCESS);
968: }