Actual source code: vi.c
1: #include <petsc/private/snesimpl.h>
2: #include <petscdm.h>
4: /*@C
5: SNESVISetComputeVariableBounds - Sets a function that is called to compute the bounds on variable for
6: (differential) variable inequalities.
8: Input Parameters:
9: + snes - the `SNES` context
10: - compute - function that computes the bounds
12: Calling sequence of `compute`:
13: + snes - the `SNES` context
14: . lower - vector to hold lower bounds
15: - higher - vector to hold upper bounds
17: Level: advanced
19: Notes:
20: Problems with bound constraints can be solved with the reduced space, `SNESVINEWTONRSLS`, and semi-smooth `SNESVINEWTONSSLS` solvers.
22: For entries with no bounds you can set `PETSC_NINFINITY` or `PETSC_INFINITY`
24: You may use `SNESVISetVariableBounds()` to provide the bounds once if they will never change
26: If you have associated a `DM` with the `SNES` and provided a function to the `DM` via `DMSetVariableBounds()` that will be used automatically
27: to provide the bounds and you need not use this function.
29: .seealso: [](sec_vi), `SNES`, `SNESVISetVariableBounds()`, `DMSetVariableBounds()`, `SNESSetFunctionDomainError()`, `SNESSetJacobianDomainError()`, `SNESVINEWTONRSLS`, `SNESVINEWTONSSLS`,
30: `SNESSetType()`, `PETSC_NINFINITY`, `PETSC_INFINITY`
31: @*/
32: PetscErrorCode SNESVISetComputeVariableBounds(SNES snes, PetscErrorCode (*compute)(SNES snes, Vec lower, Vec higher))
33: {
34: PetscErrorCode (*f)(SNES, PetscErrorCode (*)(SNES, Vec, Vec));
36: PetscFunctionBegin;
38: PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESVISetComputeVariableBounds_C", &f));
39: if (f) PetscUseMethod(snes, "SNESVISetComputeVariableBounds_C", (SNES, PetscErrorCode (*)(SNES, Vec, Vec)), (snes, compute));
40: else PetscCall(SNESVISetComputeVariableBounds_VI(snes, compute));
41: PetscFunctionReturn(PETSC_SUCCESS);
42: }
44: PetscErrorCode SNESVISetComputeVariableBounds_VI(SNES snes, SNESVIComputeVariableBoundsFn *compute)
45: {
46: PetscFunctionBegin;
47: snes->ops->computevariablebounds = compute;
48: PetscFunctionReturn(PETSC_SUCCESS);
49: }
51: static PetscErrorCode SNESVIMonitorResidual(SNES snes, PetscInt its, PetscReal fgnorm, PetscViewerAndFormat *vf)
52: {
53: Vec X, F, Finactive;
54: IS isactive;
56: PetscFunctionBegin;
58: PetscCall(SNESGetFunction(snes, &F, NULL, NULL));
59: PetscCall(SNESGetSolution(snes, &X));
60: PetscCall(SNESVIGetActiveSetIS(snes, X, F, &isactive));
61: PetscCall(VecDuplicate(F, &Finactive));
62: PetscCall(PetscObjectCompose((PetscObject)Finactive, "__Vec_bc_zero__", (PetscObject)snes));
63: PetscCall(VecCopy(F, Finactive));
64: PetscCall(VecISSet(Finactive, isactive, 0.0));
65: PetscCall(ISDestroy(&isactive));
66: PetscCall(PetscViewerPushFormat(vf->viewer, vf->format));
67: PetscCall(VecView(Finactive, vf->viewer));
68: PetscCall(PetscViewerPopFormat(vf->viewer));
69: PetscCall(PetscObjectCompose((PetscObject)Finactive, "__Vec_bc_zero__", NULL));
70: PetscCall(VecDestroy(&Finactive));
71: PetscFunctionReturn(PETSC_SUCCESS);
72: }
74: static PetscErrorCode SNESVIMonitorActive(SNES snes, PetscInt its, PetscReal fgnorm, PetscViewerAndFormat *vf)
75: {
76: Vec X, F, A;
77: IS isactive;
79: PetscFunctionBegin;
81: PetscCall(SNESGetFunction(snes, &F, NULL, NULL));
82: PetscCall(SNESGetSolution(snes, &X));
83: PetscCall(SNESVIGetActiveSetIS(snes, X, F, &isactive));
84: PetscCall(VecDuplicate(F, &A));
85: PetscCall(PetscObjectCompose((PetscObject)A, "__Vec_bc_zero__", (PetscObject)snes));
86: PetscCall(VecSet(A, 0.));
87: PetscCall(VecISSet(A, isactive, 1.));
88: PetscCall(ISDestroy(&isactive));
89: PetscCall(PetscViewerPushFormat(vf->viewer, vf->format));
90: PetscCall(VecView(A, vf->viewer));
91: PetscCall(PetscViewerPopFormat(vf->viewer));
92: PetscCall(PetscObjectCompose((PetscObject)A, "__Vec_bc_zero__", NULL));
93: PetscCall(VecDestroy(&A));
94: PetscFunctionReturn(PETSC_SUCCESS);
95: }
97: static PetscErrorCode SNESMonitorVI(SNES snes, PetscInt its, PetscReal fgnorm, void *dummy)
98: {
99: PetscViewer viewer = (PetscViewer)dummy;
100: const PetscScalar *x, *xl, *xu, *f;
101: PetscInt i, n, act[2] = {0, 0}, fact[2], N;
102: /* Number of components that actually hit the bounds (c.f. active variables) */
103: PetscInt act_bound[2] = {0, 0}, fact_bound[2];
104: PetscReal rnorm, fnorm, zerotolerance = snes->vizerotolerance;
105: double tmp;
107: PetscFunctionBegin;
109: PetscCall(VecGetLocalSize(snes->vec_sol, &n));
110: PetscCall(VecGetSize(snes->vec_sol, &N));
111: PetscCall(VecGetArrayRead(snes->xl, &xl));
112: PetscCall(VecGetArrayRead(snes->xu, &xu));
113: PetscCall(VecGetArrayRead(snes->vec_sol, &x));
114: PetscCall(VecGetArrayRead(snes->vec_func, &f));
116: rnorm = 0.0;
117: for (i = 0; i < n; i++) {
118: if ((PetscRealPart(x[i]) > PetscRealPart(xl[i]) + zerotolerance || (PetscRealPart(f[i]) <= 0.0)) && ((PetscRealPart(x[i]) < PetscRealPart(xu[i]) - zerotolerance) || PetscRealPart(f[i]) >= 0.0)) rnorm += PetscRealPart(PetscConj(f[i]) * f[i]);
119: else if (PetscRealPart(x[i]) <= PetscRealPart(xl[i]) + zerotolerance && PetscRealPart(f[i]) > 0.0) act[0]++;
120: else if (PetscRealPart(x[i]) >= PetscRealPart(xu[i]) - zerotolerance && PetscRealPart(f[i]) < 0.0) act[1]++;
121: else SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "Can never get here");
122: }
124: for (i = 0; i < n; i++) {
125: if (PetscRealPart(x[i]) <= PetscRealPart(xl[i]) + zerotolerance) act_bound[0]++;
126: else if (PetscRealPart(x[i]) >= PetscRealPart(xu[i]) - zerotolerance) act_bound[1]++;
127: }
128: PetscCall(VecRestoreArrayRead(snes->vec_func, &f));
129: PetscCall(VecRestoreArrayRead(snes->xl, &xl));
130: PetscCall(VecRestoreArrayRead(snes->xu, &xu));
131: PetscCall(VecRestoreArrayRead(snes->vec_sol, &x));
132: PetscCallMPI(MPIU_Allreduce(&rnorm, &fnorm, 1, MPIU_REAL, MPIU_SUM, PetscObjectComm((PetscObject)snes)));
133: PetscCallMPI(MPIU_Allreduce(act, fact, 2, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)snes)));
134: PetscCallMPI(MPIU_Allreduce(act_bound, fact_bound, 2, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)snes)));
135: fnorm = PetscSqrtReal(fnorm);
137: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
138: if (snes->ntruebounds) tmp = ((double)(fact[0] + fact[1])) / ((double)snes->ntruebounds);
139: else tmp = 0.0;
140: PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES VI Function norm %g Active lower constraints %" PetscInt_FMT "/%" PetscInt_FMT " upper constraints %" PetscInt_FMT "/%" PetscInt_FMT " Percent of total %g Percent of bounded %g\n", its, (double)fnorm, fact[0], fact_bound[0], fact[1], fact_bound[1], ((double)(fact[0] + fact[1])) / ((double)N), tmp));
142: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
143: PetscFunctionReturn(PETSC_SUCCESS);
144: }
146: /*
147: Checks if J^T F = 0 which implies we've found a local minimum of the norm of the function,
148: || F(u) ||_2 but not a zero, F(u) = 0. In the case when one cannot compute J^T F we use the fact that
149: 0 = (J^T F)^T W = F^T J W iff W not in the null space of J. Thanks for Jorge More
150: for this trick. One assumes that the probability that W is in the null space of J is very, very small.
151: */
152: PetscErrorCode SNESVICheckLocalMin_Private(SNES snes, Mat A, Vec F, Vec W, PetscReal fnorm, PetscBool *ismin)
153: {
154: PetscReal a1;
155: PetscBool hastranspose;
157: PetscFunctionBegin;
158: *ismin = PETSC_FALSE;
159: PetscCall(MatHasOperation(A, MATOP_MULT_TRANSPOSE, &hastranspose));
160: if (hastranspose) {
161: /* Compute || J^T F|| */
162: PetscCall(MatMultTranspose(A, F, W));
163: PetscCall(VecNorm(W, NORM_2, &a1));
164: PetscCall(PetscInfo(snes, "|| J^T F|| %g near zero implies found a local minimum\n", (double)(a1 / fnorm)));
165: if (a1 / fnorm < 1.e-4) *ismin = PETSC_TRUE;
166: } else {
167: Vec work;
168: PetscScalar result;
169: PetscReal wnorm;
171: PetscCall(VecSetRandom(W, NULL));
172: PetscCall(VecNorm(W, NORM_2, &wnorm));
173: PetscCall(VecDuplicate(W, &work));
174: PetscCall(MatMult(A, W, work));
175: PetscCall(VecDot(F, work, &result));
176: PetscCall(VecDestroy(&work));
177: a1 = PetscAbsScalar(result) / (fnorm * wnorm);
178: PetscCall(PetscInfo(snes, "(F^T J random)/(|| F ||*||random|| %g near zero implies found a local minimum\n", (double)a1));
179: if (a1 < 1.e-4) *ismin = PETSC_TRUE;
180: }
181: PetscFunctionReturn(PETSC_SUCCESS);
182: }
184: /*
185: SNESConvergedDefault_VI - Checks the convergence of the semismooth newton algorithm.
187: Notes:
188: The convergence criterion currently implemented is
189: merit < abstol
190: merit < rtol*merit_initial
191: */
192: PetscErrorCode SNESConvergedDefault_VI(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gradnorm, PetscReal fnorm, SNESConvergedReason *reason, void *dummy)
193: {
194: PetscFunctionBegin;
196: PetscAssertPointer(reason, 6);
198: *reason = SNES_CONVERGED_ITERATING;
200: if (!it) {
201: /* set parameter for default relative tolerance convergence test */
202: snes->ttol = fnorm * snes->rtol;
203: }
204: if (fnorm != fnorm) {
205: PetscCall(PetscInfo(snes, "Failed to converged, function norm is NaN\n"));
206: *reason = SNES_DIVERGED_FNORM_NAN;
207: } else if (fnorm < snes->abstol && (it || !snes->forceiteration)) {
208: PetscCall(PetscInfo(snes, "Converged due to function norm %g < %g\n", (double)fnorm, (double)snes->abstol));
209: *reason = SNES_CONVERGED_FNORM_ABS;
210: } else if (snes->nfuncs >= snes->max_funcs && snes->max_funcs >= 0) {
211: PetscCall(PetscInfo(snes, "Exceeded maximum number of function evaluations: %" PetscInt_FMT " > %" PetscInt_FMT "\n", snes->nfuncs, snes->max_funcs));
212: *reason = SNES_DIVERGED_FUNCTION_COUNT;
213: }
215: if (it && !*reason) {
216: if (fnorm < snes->ttol) {
217: PetscCall(PetscInfo(snes, "Converged due to function norm %g < %g (relative tolerance)\n", (double)fnorm, (double)snes->ttol));
218: *reason = SNES_CONVERGED_FNORM_RELATIVE;
219: }
220: }
221: PetscFunctionReturn(PETSC_SUCCESS);
222: }
224: /*
225: SNESVIProjectOntoBounds - Projects X onto the feasible region so that Xl[i] <= X[i] <= Xu[i] for i = 1...n.
227: Input Parameters:
228: . SNES - nonlinear solver context
230: Output Parameters:
231: . X - Bound projected X
233: */
235: PetscErrorCode SNESVIProjectOntoBounds(SNES snes, Vec X)
236: {
237: const PetscScalar *xl, *xu;
238: PetscScalar *x;
239: PetscInt i, n;
241: PetscFunctionBegin;
242: PetscCall(VecGetLocalSize(X, &n));
243: PetscCall(VecGetArray(X, &x));
244: PetscCall(VecGetArrayRead(snes->xl, &xl));
245: PetscCall(VecGetArrayRead(snes->xu, &xu));
247: for (i = 0; i < n; i++) {
248: if (PetscRealPart(x[i]) < PetscRealPart(xl[i])) x[i] = xl[i];
249: else if (PetscRealPart(x[i]) > PetscRealPart(xu[i])) x[i] = xu[i];
250: }
251: PetscCall(VecRestoreArray(X, &x));
252: PetscCall(VecRestoreArrayRead(snes->xl, &xl));
253: PetscCall(VecRestoreArrayRead(snes->xu, &xu));
254: PetscFunctionReturn(PETSC_SUCCESS);
255: }
257: /*@
258: SNESVIGetActiveSetIS - Gets the global indices for the active set variables
260: Input Parameters:
261: + snes - the `SNES` context
262: . X - the `snes` solution vector
263: - F - the nonlinear function vector
265: Output Parameter:
266: . ISact - active set index set
268: Level: developer
270: .seealso: [](ch_snes), `SNES`, `SNESVINEWTONRSLS`, `SNESVINEWTONSSLS`
271: @*/
272: PetscErrorCode SNESVIGetActiveSetIS(SNES snes, Vec X, Vec F, IS *ISact)
273: {
274: Vec Xl = snes->xl, Xu = snes->xu;
275: const PetscScalar *x, *f, *xl, *xu;
276: PetscInt *idx_act, i, nlocal, nloc_isact = 0, ilow, ihigh, i1 = 0;
277: PetscReal zerotolerance = snes->vizerotolerance;
279: PetscFunctionBegin;
280: PetscCall(VecGetLocalSize(X, &nlocal));
281: PetscCall(VecGetOwnershipRange(X, &ilow, &ihigh));
282: PetscCall(VecGetArrayRead(X, &x));
283: PetscCall(VecGetArrayRead(Xl, &xl));
284: PetscCall(VecGetArrayRead(Xu, &xu));
285: PetscCall(VecGetArrayRead(F, &f));
286: /* Compute active set size */
287: for (i = 0; i < nlocal; i++) {
288: if (!((PetscRealPart(x[i]) > PetscRealPart(xl[i]) + zerotolerance || (PetscRealPart(f[i]) <= 0.0)) && ((PetscRealPart(x[i]) < PetscRealPart(xu[i]) - zerotolerance) || PetscRealPart(f[i]) >= 0.0))) nloc_isact++;
289: }
291: PetscCall(PetscMalloc1(nloc_isact, &idx_act));
293: /* Set active set indices */
294: for (i = 0; i < nlocal; i++) {
295: if (!((PetscRealPart(x[i]) > PetscRealPart(xl[i]) + zerotolerance || (PetscRealPart(f[i]) <= 0.0)) && ((PetscRealPart(x[i]) < PetscRealPart(xu[i]) - zerotolerance) || PetscRealPart(f[i]) >= 0.0))) idx_act[i1++] = ilow + i;
296: }
298: /* Create active set IS */
299: PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)snes), nloc_isact, idx_act, PETSC_OWN_POINTER, ISact));
301: PetscCall(VecRestoreArrayRead(X, &x));
302: PetscCall(VecRestoreArrayRead(Xl, &xl));
303: PetscCall(VecRestoreArrayRead(Xu, &xu));
304: PetscCall(VecRestoreArrayRead(F, &f));
305: PetscFunctionReturn(PETSC_SUCCESS);
306: }
308: /*@
309: SNESVIComputeInactiveSetFnorm - Computes the function norm for variational inequalities on the inactive set
311: Input Parameters:
312: + snes - the `SNES` context
313: . F - the nonlinear function vector
314: - X - the `SNES` solution vector
316: Output Parameter:
317: . fnorm - the function norm
319: Level: developer
321: .seealso: [](ch_snes), `SNES`, `SNESVINEWTONRSLS`, `SNESVINEWTONSSLS`, `SNESLineSearchSetVIFunctions()`
322: @*/
323: PetscErrorCode SNESVIComputeInactiveSetFnorm(SNES snes, Vec F, Vec X, PetscReal *fnorm)
324: {
325: const PetscScalar *x, *xl, *xu, *f;
326: PetscInt i, n;
327: PetscReal zerotolerance = snes->vizerotolerance;
329: PetscFunctionBegin;
331: PetscAssertPointer(fnorm, 4);
332: PetscCall(VecGetLocalSize(X, &n));
333: PetscCall(VecGetArrayRead(snes->xl, &xl));
334: PetscCall(VecGetArrayRead(snes->xu, &xu));
335: PetscCall(VecGetArrayRead(X, &x));
336: PetscCall(VecGetArrayRead(F, &f));
337: *fnorm = 0.0;
338: for (i = 0; i < n; i++) {
339: if ((PetscRealPart(x[i]) > PetscRealPart(xl[i]) + zerotolerance || (PetscRealPart(f[i]) <= 0.0)) && ((PetscRealPart(x[i]) < PetscRealPart(xu[i]) - zerotolerance) || PetscRealPart(f[i]) >= 0.0)) *fnorm += PetscRealPart(PetscConj(f[i]) * f[i]);
340: }
341: PetscCall(VecRestoreArrayRead(F, &f));
342: PetscCall(VecRestoreArrayRead(snes->xl, &xl));
343: PetscCall(VecRestoreArrayRead(snes->xu, &xu));
344: PetscCall(VecRestoreArrayRead(X, &x));
345: PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, fnorm, 1, MPIU_REAL, MPIU_SUM, PetscObjectComm((PetscObject)snes)));
346: *fnorm = PetscSqrtReal(*fnorm);
347: PetscFunctionReturn(PETSC_SUCCESS);
348: }
350: /*@
351: SNESVIComputeInactiveSetFtY - Computes the directional derivative for variational inequalities on the inactive set,
352: assuming that there exists some $G(x)$ for which the `SNESFunctionFn` $F(x) = grad G(x)$ (relevant for some line search algorithms)
354: Input Parameters:
355: + snes - the `SNES` context
356: . F - the nonlinear function vector
357: . X - the `SNES` solution vector
358: - Y - the direction vector
360: Output Parameter:
361: . fty - the directional derivative
363: Level: developer
365: .seealso: [](ch_snes), `SNES`, `SNESVINEWTONRSLS`, `SNESVINEWTONSSLS`
366: @*/
367: PetscErrorCode SNESVIComputeInactiveSetFtY(SNES snes, Vec F, Vec X, Vec Y, PetscScalar *fty)
368: {
369: const PetscScalar *x, *xl, *xu, *y, *f;
370: PetscInt i, n;
371: PetscReal zerotolerance = snes->vizerotolerance;
373: PetscFunctionBegin;
375: PetscAssertPointer(fty, 5);
376: PetscCall(VecGetLocalSize(X, &n));
377: PetscCall(VecGetArrayRead(F, &f));
378: PetscCall(VecGetArrayRead(X, &x));
379: PetscCall(VecGetArrayRead(snes->xl, &xl));
380: PetscCall(VecGetArrayRead(snes->xu, &xu));
381: PetscCall(VecGetArrayRead(Y, &y));
382: *fty = 0.0;
383: for (i = 0; i < n; i++) {
384: if ((PetscRealPart(x[i]) > PetscRealPart(xl[i]) + zerotolerance || (PetscRealPart(f[i]) <= 0.0)) && ((PetscRealPart(x[i]) < PetscRealPart(xu[i]) - zerotolerance) || PetscRealPart(f[i]) >= 0.0)) *fty += f[i] * PetscConj(y[i]);
385: }
386: PetscCall(VecRestoreArrayRead(F, &f));
387: PetscCall(VecRestoreArrayRead(X, &x));
388: PetscCall(VecRestoreArrayRead(snes->xl, &xl));
389: PetscCall(VecRestoreArrayRead(snes->xu, &xu));
390: PetscCall(VecRestoreArrayRead(Y, &y));
391: PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, fty, 1, MPIU_SCALAR, MPIU_SUM, PetscObjectComm((PetscObject)snes)));
392: PetscFunctionReturn(PETSC_SUCCESS);
393: }
395: static PetscErrorCode SNESVIDMComputeVariableBounds(SNES snes, Vec xl, Vec xu)
396: {
397: PetscFunctionBegin;
398: PetscCall(DMComputeVariableBounds(snes->dm, xl, xu));
399: PetscFunctionReturn(PETSC_SUCCESS);
400: }
402: /*
403: SNESSetUp_VI - Does setup common to all VI solvers -- basically makes sure bounds have been properly set up
404: of the SNESVI nonlinear solver.
406: Input Parameter:
407: . snes - the SNES context
409: Application Interface Routine: SNESSetUp()
411: Notes:
412: For basic use of the SNES solvers, the user need not explicitly call
413: SNESSetUp(), since these actions will automatically occur during
414: the call to SNESSolve().
415: */
416: PetscErrorCode SNESSetUp_VI(SNES snes)
417: {
418: PetscInt i_start[3], i_end[3];
420: PetscFunctionBegin;
421: PetscCall(SNESSetWorkVecs(snes, 1));
422: PetscCall(SNESSetUpMatrices(snes));
424: if (!snes->ops->computevariablebounds && snes->dm) {
425: PetscBool flag;
426: PetscCall(DMHasVariableBounds(snes->dm, &flag));
427: if (flag) snes->ops->computevariablebounds = SNESVIDMComputeVariableBounds;
428: }
429: if (!snes->usersetbounds) {
430: if (snes->ops->computevariablebounds) {
431: if (!snes->xl) PetscCall(VecDuplicate(snes->vec_sol, &snes->xl));
432: if (!snes->xu) PetscCall(VecDuplicate(snes->vec_sol, &snes->xu));
433: PetscUseTypeMethod(snes, computevariablebounds, snes->xl, snes->xu);
434: } else if (!snes->xl && !snes->xu) {
435: /* If the lower and upper bound on variables are not set, set it to -Inf and Inf */
436: PetscCall(VecDuplicate(snes->vec_sol, &snes->xl));
437: PetscCall(VecSet(snes->xl, PETSC_NINFINITY));
438: PetscCall(VecDuplicate(snes->vec_sol, &snes->xu));
439: PetscCall(VecSet(snes->xu, PETSC_INFINITY));
440: } else {
441: /* Check if lower bound, upper bound and solution vector distribution across the processors is identical */
442: PetscCall(VecGetOwnershipRange(snes->vec_sol, i_start, i_end));
443: PetscCall(VecGetOwnershipRange(snes->xl, i_start + 1, i_end + 1));
444: PetscCall(VecGetOwnershipRange(snes->xu, i_start + 2, i_end + 2));
445: if ((i_start[0] != i_start[1]) || (i_start[0] != i_start[2]) || (i_end[0] != i_end[1]) || (i_end[0] != i_end[2]))
446: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Distribution of lower bound, upper bound and the solution vector should be identical across all the processors.");
447: }
448: }
449: PetscFunctionReturn(PETSC_SUCCESS);
450: }
451: PetscErrorCode SNESReset_VI(SNES snes)
452: {
453: PetscFunctionBegin;
454: PetscCall(VecDestroy(&snes->xl));
455: PetscCall(VecDestroy(&snes->xu));
456: snes->usersetbounds = PETSC_FALSE;
457: PetscFunctionReturn(PETSC_SUCCESS);
458: }
460: /*
461: SNESDestroy_VI - Destroys the private SNES_VI context that was created
462: with SNESCreate_VI().
464: Input Parameter:
465: . snes - the SNES context
467: Application Interface Routine: SNESDestroy()
468: */
469: PetscErrorCode SNESDestroy_VI(SNES snes)
470: {
471: PetscFunctionBegin;
472: PetscCall(PetscFree(snes->data));
474: /* clear composed functions */
475: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESVISetVariableBounds_C", NULL));
476: PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESVISetComputeVariableBounds_C", NULL));
477: PetscFunctionReturn(PETSC_SUCCESS);
478: }
480: /*@
481: SNESVISetVariableBounds - Sets the lower and upper bounds for the solution vector. `xl` <= x <= `xu`. This allows solving
482: (differential) variable inequalities.
484: Input Parameters:
485: + snes - the `SNES` context.
486: . xl - lower bound.
487: - xu - upper bound.
489: Level: advanced
491: Notes:
492: If this routine is not called then the lower and upper bounds are set to
493: `PETSC_NINFINITY` and `PETSC_INFINITY` respectively during `SNESSetUp()`.
495: Problems with bound constraints can be solved with the reduced space, `SNESVINEWTONRSLS` or semi-smooth `SNESVINEWTONSSLS` solvers.
497: For particular components that have no bounds you can use `PETSC_NINFINITY` or `PETSC_INFINITY`
499: `SNESVISetComputeVariableBounds()` can be used to provide a function that computes the bounds. This should be used if you are using, for example, grid
500: sequencing and need bounds set for a variety of vectors
502: .seealso: [](sec_vi), `SNES`, `SNESVIGetVariableBounds()`, `SNESVISetComputeVariableBounds()`, `SNESSetFunctionDomainError()`, `SNESSetJacobianDomainError()`, `SNESVINEWTONRSLS`, `SNESVINEWTONSSLS`, `SNESSetType()`, `PETSC_NINFINITY`, `PETSC_INFINITY`
503: @*/
504: PetscErrorCode SNESVISetVariableBounds(SNES snes, Vec xl, Vec xu)
505: {
506: PetscErrorCode (*f)(SNES, Vec, Vec);
508: PetscFunctionBegin;
512: PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESVISetVariableBounds_C", &f));
513: if (f) PetscUseMethod(snes, "SNESVISetVariableBounds_C", (SNES, Vec, Vec), (snes, xl, xu));
514: else PetscCall(SNESVISetVariableBounds_VI(snes, xl, xu));
515: snes->usersetbounds = PETSC_TRUE;
516: PetscFunctionReturn(PETSC_SUCCESS);
517: }
519: PetscErrorCode SNESVISetVariableBounds_VI(SNES snes, Vec xl, Vec xu)
520: {
521: const PetscScalar *xxl, *xxu;
522: PetscInt i, n, cnt = 0;
524: PetscFunctionBegin;
525: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
526: PetscCheck(snes->vec_func, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() first");
527: {
528: PetscInt xlN, xuN, N;
529: PetscCall(VecGetSize(xl, &xlN));
530: PetscCall(VecGetSize(xu, &xuN));
531: PetscCall(VecGetSize(snes->vec_func, &N));
532: PetscCheck(xlN == N, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Incompatible vector lengths lower bound = %" PetscInt_FMT " solution vector = %" PetscInt_FMT, xlN, N);
533: PetscCheck(xuN == N, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Incompatible vector lengths: upper bound = %" PetscInt_FMT " solution vector = %" PetscInt_FMT, xuN, N);
534: }
535: PetscCall(PetscObjectReference((PetscObject)xl));
536: PetscCall(PetscObjectReference((PetscObject)xu));
537: PetscCall(VecDestroy(&snes->xl));
538: PetscCall(VecDestroy(&snes->xu));
539: snes->xl = xl;
540: snes->xu = xu;
541: PetscCall(VecGetLocalSize(xl, &n));
542: PetscCall(VecGetArrayRead(xl, &xxl));
543: PetscCall(VecGetArrayRead(xu, &xxu));
544: for (i = 0; i < n; i++) cnt += ((xxl[i] != PETSC_NINFINITY) || (xxu[i] != PETSC_INFINITY));
546: PetscCallMPI(MPIU_Allreduce(&cnt, &snes->ntruebounds, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)snes)));
547: PetscCall(VecRestoreArrayRead(xl, &xxl));
548: PetscCall(VecRestoreArrayRead(xu, &xxu));
549: PetscFunctionReturn(PETSC_SUCCESS);
550: }
552: /*@
553: SNESVIGetVariableBounds - Gets the lower and upper bounds for the solution vector. `xl` <= x <= `xu`. These are used in solving
554: (differential) variable inequalities.
556: Input Parameters:
557: + snes - the `SNES` context.
558: . xl - lower bound (may be `NULL`)
559: - xu - upper bound (may be `NULL`)
561: Level: advanced
563: Note:
564: These vectors are owned by the `SNESVI` and should not be destroyed by the caller
566: .seealso: [](sec_vi), `SNES`, `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()`, `SNESSetFunctionDomainError()`, `SNESSetJacobianDomainError()`, `SNESVINEWTONRSLS`, `SNESVINEWTONSSLS`, `SNESSetType()`, `PETSC_NINFINITY`, `PETSC_INFINITY`
567: @*/
568: PetscErrorCode SNESVIGetVariableBounds(SNES snes, Vec *xl, Vec *xu)
569: {
570: PetscFunctionBegin;
571: PetscCheck(snes->usersetbounds, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must set SNESVI bounds before calling SNESVIGetVariableBounds()");
572: if (xl) *xl = snes->xl;
573: if (xu) *xu = snes->xu;
574: PetscFunctionReturn(PETSC_SUCCESS);
575: }
577: PetscErrorCode SNESSetFromOptions_VI(SNES snes, PetscOptionItems PetscOptionsObject)
578: {
579: PetscBool flg = PETSC_FALSE;
581: PetscFunctionBegin;
582: PetscOptionsHeadBegin(PetscOptionsObject, "SNES VI options");
583: PetscCall(PetscOptionsReal("-snes_vi_zero_tolerance", "Tolerance for considering x[] value to be on a bound", "None", snes->vizerotolerance, &snes->vizerotolerance, NULL));
584: PetscCall(PetscOptionsBool("-snes_vi_monitor", "Monitor all non-active variables", "SNESMonitorResidual", flg, &flg, NULL));
585: if (flg) PetscCall(SNESMonitorSet(snes, SNESMonitorVI, PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)), NULL));
586: flg = PETSC_FALSE;
587: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_vi_monitor_residual", "View residual at each iteration, using zero for active constraints", "SNESVIMonitorResidual", SNESVIMonitorResidual, NULL));
588: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_vi_monitor_active", "View active set at each iteration, using zero for inactive dofs", "SNESVIMonitorActive", SNESVIMonitorActive, NULL));
589: PetscOptionsHeadEnd();
590: PetscFunctionReturn(PETSC_SUCCESS);
591: }