Actual source code: meshmgsnes.c
1: #include <petscmg.h> /*I "petscmg.h" I*/
2: #include <petscdmmg.h> /*I "petscdmmg.h" I*/
3: #include <petscmesh.h> /*I "petscmesh.h" I*/
4: #include <Selection.hh>
6: /* Just to set iterations */
7: #include private/snesimpl.h
9: PetscErrorCode DMMGFormFunctionMesh(SNES snes, Vec X, Vec F, void *ptr);
11: #if 0
12: PetscErrorCode CreateNullSpace(DMMG dmmg, Vec *nulls) {
13: Mesh mesh = (Mesh) dmmg->dm;
14: Vec nS = nulls[0];
15: SectionReal nullSpace;
19: MeshGetSectionReal(mesh, "nullSpace", &nullSpace);
20: {
21: ALE::Obj<PETSC_MESH_TYPE> m;
22: ALE::Obj<PETSC_MESH_TYPE::real_section_type> s;
24: MeshGetMesh(mesh, m);
25: SectionRealGetSection(nullSpace, s);
26: ALE::Obj<ALE::Discretization> disc = m->getDiscretization("p");
27: const int dim = m->getDimension();
29: for(int d = 0; d <= dim; ++d) {
30: const int numDof = disc->getNumDof(d);
32: if (numDof) {
33: const ALE::Obj<PETSC_MESH_TYPE::label_sequence>& stratum = m->depthStratum(d);
34: const PETSC_MESH_TYPE::label_sequence::iterator end = stratum->end();
35: double *values = new double[numDof];
37: for(PETSC_MESH_TYPE::label_sequence::iterator p_iter = stratum->begin(); p_iter != end; ++p_iter) {
38: for(int i = 0; i < numDof; ++i) values[i] = 1.0;
39: s->updatePoint(*p_iter, values);
40: }
41: }
42: }
43: }
44: SectionRealToVec(nullSpace, mesh, SCATTER_FORWARD, nS);
45: std::cout << "Null space:" << std::endl;
46: VecView(nS, PETSC_VIEWER_STDOUT_SELF);
47: SectionRealDestroy(nullSpace);
48: return(0);
49: }
50: #endif
52: /* Nonlinear relaxation on all the equations with an initial guess in x */
56: PetscErrorCode Relax_Mesh(DMMG *dmmg, Mesh mesh, MatSORType flag, int its, Vec X, Vec B)
57: {
58: SectionReal sectionX, sectionB, cellX;
59: Mesh smallMesh;
60: DMMG *smallDmmg;
61: DALocalFunction1 func;
62: DALocalFunction1 jac;
63: ALE::Obj<PETSC_MESH_TYPE> m;
64: ALE::Obj<PETSC_MESH_TYPE::real_section_type> sX;
65: ALE::Obj<PETSC_MESH_TYPE::real_section_type> sB;
66: PetscTruth fasDebug;
67: PetscErrorCode ierr;
70: PetscOptionsHasName(dmmg[0]->prefix, "-dmmg_fas_debug", &fasDebug);
71: if (fasDebug) {PetscPrintf(dmmg[0]->comm, " FAS mesh relaxation\n");}
72: if (its <= 0) SETERRQ1(PETSC_ERR_ARG_WRONG, "Relaxation requires global its %D positive", its);
73: MeshCreate(PETSC_COMM_SELF, &smallMesh);
74: DMMGCreate(PETSC_COMM_SELF, -1, PETSC_NULL, &smallDmmg);
75: //DMMGSetMatType(smallDmmg, MATSEQDENSE);
76: DMMGSetOptionsPrefix(smallDmmg, "fas_");
77: DMMGSetUser(smallDmmg, 0, DMMGGetUser(dmmg, 0));
78: DMMGGetSNESLocal(dmmg, &func, &jac);
79: MeshGetMesh(mesh, m);
80: MeshGetSectionReal(mesh, "default", §ionX);
81: SectionRealToVec(sectionX, mesh, SCATTER_REVERSE, X);
82: SectionRealGetSection(sectionX, sX);
83: MeshGetSectionReal(mesh, "constant", §ionB);
84: SectionRealToVec(sectionB, mesh, SCATTER_REVERSE, B);
85: SectionRealGetSection(sectionB, sB);
86: SectionRealCreate(PETSC_COMM_SELF, &cellX);
87: //const ALE::Obj<PETSC_MESH_TYPE::sieve_type>& sieve = m->getSieve();
88: //const ALE::Obj<PETSC_MESH_TYPE::label_sequence>& cells = m->heightStratum(0);
89: //const int depth = m->depth();
90: //const ALE::Obj<PETSC_MESH_TYPE::label_type>& marker = m->getLabel("marker");
91: //const int cellDof = m->sizeWithBC(sX, *cells->begin());
93: #ifdef PETSC_OPT_SIEVE
94: SETERRQ(PETSC_ERR_SUP, "I am being lazy, bug me.");
95: #else
96: ALE::Obj<PETSC_MESH_TYPE::names_type> fields = m->getDiscretizations();
97: std::map<std::string, ALE::Obj<ALE::Discretization> > sDiscs;
99: for(PETSC_MESH_TYPE::names_type::iterator f_iter = fields->begin(); f_iter != fields->end(); ++f_iter) {
100: const ALE::Obj<ALE::Discretization>& disc = m->getDiscretization(*f_iter);
101: ALE::Obj<ALE::Discretization> sDisc = new ALE::Discretization(disc->comm(), disc->debug());
103: sDisc->setQuadratureSize(disc->getQuadratureSize());
104: sDisc->setQuadraturePoints(disc->getQuadraturePoints());
105: sDisc->setQuadratureWeights(disc->getQuadratureWeights());
106: sDisc->setBasisSize(disc->getBasisSize());
107: sDisc->setBasis(disc->getBasis());
108: sDisc->setBasisDerivatives(disc->getBasisDerivatives());
109: for(int d = 0; d <= m->getDimension(); ++d) {
110: sDisc->setNumDof(d, disc->getNumDof(d));
111: sDisc->setDofClass(d, disc->getDofClass(d));
112: }
113: if (disc->getBoundaryConditions()->size()) {
114: if (fasDebug) {std::cout << "Adding BC for field " << *f_iter << std::endl;}
115: ALE::Obj<ALE::BoundaryCondition> sBC = new ALE::BoundaryCondition(disc->comm(), disc->debug());
116: sBC->setLabelName("marker");
117: sBC->setMarker(1);
118: sBC->setFunction(PETSC_NULL);
119: sBC->setDualIntegrator(PETSC_NULL);
120: sDisc->setBoundaryCondition(sBC);
121: }
122: sDiscs[*f_iter] = sDisc;
123: }
124: while(its--) {
125: if (fasDebug) {PetscPrintf(dmmg[0]->comm, " forward sweep %d\n", its);}
126: if (flag & SOR_FORWARD_SWEEP || flag & SOR_LOCAL_FORWARD_SWEEP){
127: // Loop over all cells
128: // This is an overlapping block SOR, but it is easier and seems more natural than doing each unknown
129: for(PETSC_MESH_TYPE::label_sequence::iterator c_iter = cells->begin(); c_iter != cells->end(); ++c_iter) {
130: ALE::Obj<PETSC_MESH_TYPE::sieve_type::supportSet> cellBlock = sieve->nSupport(sieve->nCone(*c_iter, depth), depth);
131: ALE::Obj<PETSC_MESH_TYPE> sm = ALE::Selection<PETSC_MESH_TYPE>::submesh(m, cellBlock);
132: ALE::Obj<PETSC_MESH_TYPE::real_section_type> ssX = sm->getRealSection("default");
133: const ALE::Obj<PETSC_MESH_TYPE::label_type>& cellMarker = sm->createLabel("marker");
135: if (fasDebug) {PetscPrintf(dmmg[0]->comm, " forward sweep cell %d\n", *c_iter);}
136: SectionRealSetSection(cellX, ssX);
137: // Assign BC to mesh
138: for(PETSC_MESH_TYPE::sieve_type::supportSet::iterator b_iter = cellBlock->begin(); b_iter != cellBlock->end(); ++b_iter) {
139: const ALE::Obj<PETSC_MESH_TYPE::coneArray> closure = ALE::SieveAlg<PETSC_MESH_TYPE>::closure(m, *b_iter);
140: const PETSC_MESH_TYPE::coneArray::iterator end = closure->end();
141: const bool isCell = *b_iter == *c_iter;
143: for(PETSC_MESH_TYPE::coneArray::iterator cl_iter = closure->begin(); cl_iter != end; ++cl_iter) {
144: if (isCell) {
145: sm->setValue(cellMarker, *cl_iter, m->getValue(marker, *cl_iter));
146: } else {
147: if (sm->height(*cl_iter) == 0) {
148: sm->setValue(cellMarker, *cl_iter, 2);
149: } else if (sm->getValue(cellMarker, *cl_iter, -1) < 0) {
150: sm->setValue(cellMarker, *cl_iter, 1);
151: }
152: }
153: }
154: }
155: for(std::map<std::string, ALE::Obj<ALE::Discretization> >::iterator d_iter = sDiscs.begin(); d_iter != sDiscs.end(); ++d_iter) {
156: sm->setDiscretization(d_iter->first, d_iter->second);
157: }
158: // Create field
159: sm->setupField(ssX, 2, true);
160: // Setup constant
161: sm->setRealSection("constant", sB);
162: // Setup DMMG
163: MeshSetMesh(smallMesh, sm);
164: DMMGSetDM(smallDmmg, (DM) smallMesh);
165: DMMGSetSNESLocal(smallDmmg, func, jac, 0, 0);
166: DMMGSetFromOptions(smallDmmg);
167: // TODO: Construct null space, if necessary
168: //DMMGSetNullSpace(smallDmmg, PETSC_FALSE, 1, CreateNullSpace);
169: //ALE::Obj<PETSC_MESH_TYPE::real_section_type> nullSpace = sm->getRealSection("nullSpace");
170: //sm->setupField(nullSpace, 2, true);
171: // Fill in intial guess with BC values
172: for(PETSC_MESH_TYPE::sieve_type::supportSet::iterator b_iter = cellBlock->begin(); b_iter != cellBlock->end(); ++b_iter) {
173: sm->updateAll(ssX, *b_iter, m->restrictNew(sX, *b_iter));
174: }
175: if (fasDebug) {
176: sX->view("Initial solution guess");
177: ssX->view("Cell solution guess");
178: }
179: // Solve
180: DMMGSolve(smallDmmg);
181: // Update global solution with local solution
182: SectionRealToVec(cellX, smallMesh, SCATTER_REVERSE, DMMGGetx(smallDmmg));
183: m->updateAll(sX, *c_iter, sm->restrictNew(ssX, *c_iter));
184: if (fasDebug) {
185: ssX->view("Cell solution final");
186: sX->view("Final solution");
187: }
188: }
189: }
190: if (flag & SOR_BACKWARD_SWEEP || flag & SOR_LOCAL_BACKWARD_SWEEP){
191: }
192: }
193: #endif
194: sB->zero();
195: SectionRealToVec(sectionX, mesh, SCATTER_FORWARD, X);
196: SectionRealDestroy(sectionX);
197: SectionRealDestroy(sectionB);
198: SectionRealDestroy(cellX);
199: DMMGDestroy(smallDmmg);
200: MeshDestroy(smallMesh);
201: return(0);
202: }
205: /*
206: This is alpha FAS code.
208: R is the usual multigrid restriction (e.g. the tranpose of piecewise linear interpolation)
209: Q is either a scaled injection or the usual R
210: */
213: PetscErrorCode DMMGSolveFAS_Mesh(DMMG *dmmg, PetscInt level)
214: {
215: SNES snes = dmmg[level]->snes;
216: PetscReal norm;
217: PetscInt i, j, k;
218: PetscTruth fasDebug;
222: PetscOptionsHasName(dmmg[0]->prefix, "-dmmg_fas_debug", &fasDebug);
223: VecSet(dmmg[level]->r, 0.0);
224: /* for(j = 1; j <= level; ++j) { */
225: /* if (!dmmg[j]->inject) { */
226: /* DMGetInjection(dmmg[j-1]->dm, dmmg[j]->dm, &dmmg[j]->inject); */
227: /* } */
228: /* } */
230: for(i = 0, snes->iter = 1; i < 100; ++i, ++snes->iter) {
231: PetscPrintf(dmmg[0]->comm, "FAS iteration %d\n", i);
232: for(j = level; j > 0; j--) {
233: if (dmmg[j]->monitorall) {PetscPrintf(dmmg[0]->comm, " FAS level %d\n", j);}
234: /* Relax on fine mesh to obtain x^{new}_{fine}, residual^{new}_{fine} = F_{fine}(x^{new}_{fine}) \approx 0 */
235: Relax_Mesh(dmmg, (Mesh) dmmg[j]->dm, SOR_SYMMETRIC_SWEEP, dmmg[j]->presmooth, dmmg[j]->x, dmmg[j]->r);
236: DMMGFormFunctionMesh(0,dmmg[j]->x,dmmg[j]->w,dmmg[j]);
238: /* residual^{old}_fine} - residual^{new}_{fine} = F(x^{old}_{fine}) - residual^{new}_{fine} */
239: VecAYPX(dmmg[j]->w,-1.0,dmmg[j]->r);
241: if (j == level || dmmg[j]->monitorall) {
242: /* norm( residual_fine - f(x_fine) ) */
243: VecNorm(dmmg[j]->w,NORM_2,&norm);
244: if (dmmg[j]->monitorall) {
245: for (k=0; k<level-j+1; k++) {PetscPrintf(dmmg[j]->comm," ");}
246: PetscPrintf(dmmg[j]->comm,"FAS lvl %d function norm %G\n",j,norm);
247: }
248: if (j == level) {
249: if (norm < dmmg[level]->abstol) goto theend;
250: if (i == 0) {
251: dmmg[level]->rrtol = norm*dmmg[level]->rtol;
252: } else {
253: if (norm < dmmg[level]->rrtol) goto theend;
254: }
255: }
256: }
258: /* residual^{new}_{coarse} = R*(residual^{old}_fine} - residual^{new}_{fine}) */
259: MatRestrict(dmmg[j]->R, dmmg[j]->w, dmmg[j-1]->r);
260:
261: /* F_{coarse}(R*x^{new}_{fine}) */
262: MatRestrict(dmmg[j]->R, dmmg[j]->x, dmmg[j-1]->x);
263: /* VecScatterBegin(dmmg[j]->inject,dmmg[j]->x,dmmg[j-1]->x,INSERT_VALUES,SCATTER_FORWARD); */
264: /* VecScatterEnd(dmmg[j]->inject,dmmg[j]->x,dmmg[j-1]->x,INSERT_VALUES,SCATTER_FORWARD); */
265: DMMGFormFunctionMesh(0,dmmg[j-1]->x,dmmg[j-1]->w,dmmg[j-1]);
267: /* residual_coarse = F_{coarse}(R*x_{fine}) + R*(residual^{old}_fine} - residual^{new}_{fine}) */
268: VecAYPX(dmmg[j-1]->r,1.0,dmmg[j-1]->w);
270: /* save R*x^{new}_{fine} into b (needed when interpolating compute x back up) */
271: VecCopy(dmmg[j-1]->x,dmmg[j-1]->b);
272: }
274: if (dmmg[0]->monitorall) {
275: for (k=0; k<level+1; k++) {PetscPrintf(dmmg[0]->comm," ");}
276: PetscPrintf(dmmg[0]->comm, "FAS coarse grid\n");
277: }
278: if (level == 0) {
279: DMMGFormFunctionMesh(0,dmmg[0]->x,dmmg[0]->w,dmmg[0]);
280: VecAYPX(dmmg[j]->w,-1.0,dmmg[j]->r);
281: VecNorm(dmmg[0]->w,NORM_2,&norm);
282: if (norm < dmmg[level]->abstol) goto theend;
283: if (i == 0) {
284: dmmg[level]->rrtol = norm*dmmg[level]->rtol;
285: }
286: }
287: Relax_Mesh(dmmg, (Mesh) dmmg[0]->dm, SOR_SYMMETRIC_SWEEP, dmmg[0]->coarsesmooth, dmmg[0]->x, dmmg[0]->r);
288: if (level == 0 || dmmg[0]->monitorall) {
289: DMMGFormFunctionMesh(0,dmmg[0]->x,dmmg[0]->w,dmmg[0]);
290: if (fasDebug) {
291: SectionReal residual;
293: MeshGetSectionReal((Mesh) dmmg[0]->dm, "default", &residual);
294: SectionRealView(residual, PETSC_VIEWER_STDOUT_WORLD);
295: SectionRealDestroy(residual);
296: }
297: VecAXPY(dmmg[0]->w,-1.0,dmmg[0]->r);
298: VecNorm(dmmg[0]->w,NORM_2,&norm);
299: for (k=0; k<level+1; k++) {PetscPrintf(dmmg[0]->comm," ");}
300: PetscPrintf(dmmg[0]->comm,"FAS coarse grid function norm %G\n",norm);
301: if (level == 0) {
302: if (norm < dmmg[level]->abstol) goto theend;
303: if (norm < dmmg[level]->rrtol) goto theend;
304: }
305: }
307: for (j=1; j<=level; j++) {
308: PetscPrintf(dmmg[0]->comm, " FAS level %d\n", j);
309: /* x^{new}_{coarse} - R*x^{new}_{fine} */
310: VecAXPY(dmmg[j-1]->x,-1.0,dmmg[j-1]->b);
311: /* x_fine = x_fine + R'*(x^{new}_{coarse} - R*x^{new}_{fine}) */
312: MatInterpolateAdd(dmmg[j]->R, dmmg[j-1]->x, dmmg[j]->x, dmmg[j]->x);
314: if (dmmg[j]->monitorall) {
315: /* norm( F(x_fine) - residual_fine ) */
316: DMMGFormFunctionMesh(0,dmmg[j]->x,dmmg[j]->w,dmmg[j]);
317: VecAXPY(dmmg[j]->w,-1.0,dmmg[j]->r);
318: VecNorm(dmmg[j]->w,NORM_2,&norm);
319: for (k=0; k<level-j+1; k++) {PetscPrintf(dmmg[j]->comm," ");}
320: PetscPrintf(dmmg[j]->comm,"FAS lvl %d function norm before postsmooth %G\n",j,norm);
321: }
323: /* Relax residual_fine - F(x_fine) = 0 */
324: for (k=0; k<dmmg[j]->postsmooth; k++) {
325: Relax_Mesh(dmmg, (Mesh) dmmg[j]->dm, SOR_SYMMETRIC_SWEEP, 1, dmmg[j]->x, dmmg[j]->r);
326: }
328: if ((j == level) || dmmg[j]->monitorall) {
329: /* norm( F(x_fine) - residual_fine ) */
330: DMMGFormFunctionMesh(0,dmmg[j]->x,dmmg[j]->w,dmmg[j]);
331: VecAXPY(dmmg[j]->w,-1.0,dmmg[j]->r);
332: VecNorm(dmmg[j]->w,NORM_2,&norm);
333: for (k=0; k<level-j+1; k++) {PetscPrintf(dmmg[j]->comm," ");}
334: PetscPrintf(dmmg[j]->comm,"FAS lvl %d function norm %G\n",j,norm);
335: if (j == level) {
336: if (norm < dmmg[level]->abstol) goto theend;
337: if (norm < dmmg[level]->rrtol) goto theend;
338: }
339: }
340: }
342: if (dmmg[level]->monitor){
343: DMMGFormFunctionMesh(0,dmmg[level]->x,dmmg[level]->w,dmmg[level]);
344: VecNorm(dmmg[level]->w,NORM_2,&norm);
345: PetscPrintf(dmmg[level]->comm,"%D FAS function norm %G\n",i+1,norm);
346: }
347: }
348: theend:
349: return(0);
350: }