Actual source code: stag1d.c
1: /*
2: Functions specific to the 1-dimensional implementation of DMStag
3: */
4: #include <petsc/private/dmstagimpl.h>
6: /*@
7: DMStagCreate1d - Create an object to manage data living on the elements and vertices of a parallelized regular 1D grid.
9: Collective
11: Input Parameters:
12: + comm - MPI communicator
13: . bndx - boundary type: `DM_BOUNDARY_NONE`, `DM_BOUNDARY_PERIODIC`, or `DM_BOUNDARY_GHOSTED`
14: . M - global number of elements
15: . dof0 - number of degrees of freedom per vertex/0-cell
16: . dof1 - number of degrees of freedom per element/1-cell
17: . stencilType - ghost/halo region type: `DMSTAG_STENCIL_BOX` or `DMSTAG_STENCIL_NONE`
18: . stencilWidth - width, in elements, of halo/ghost region
19: - lx - array of local sizes, of length equal to the comm size, summing to `M` or `NULL`
21: Output Parameter:
22: . dm - the new `DMSTAG` object
24: Options Database Keys:
25: + -dm_view - calls `DMViewFromOptions()` at the conclusion of `DMSetUp()`
26: . -stag_grid_x nx - number of elements in the x direction
27: . -stag_ghost_stencil_width - width of ghost region, in elements
28: - -stag_boundary_type_x (none|ghosted|periodic) - `DMBoundaryType` value
30: Level: beginner
32: Notes:
33: You must call `DMSetUp()` after this call before using the `DM`.
34: If you wish to use the options database (see the keys above) to change values in the `DMSTAG`, you must call
35: `DMSetFromOptions()` after this function but before `DMSetUp()`.
37: .seealso: [](ch_stag), `DMSTAG`, `DMStagCreate2d()`, `DMStagCreate3d()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateLocalVector()`, `DMLocalToGlobalBegin()`, `DMDACreate1d()`
38: @*/
39: PetscErrorCode DMStagCreate1d(MPI_Comm comm, DMBoundaryType bndx, PetscInt M, PetscInt dof0, PetscInt dof1, DMStagStencilType stencilType, PetscInt stencilWidth, const PetscInt lx[], DM *dm)
40: {
41: PetscMPIInt size;
43: PetscFunctionBegin;
44: PetscCallMPI(MPI_Comm_size(comm, &size));
45: PetscCall(DMCreate(comm, dm));
46: PetscCall(DMSetDimension(*dm, 1));
47: PetscCall(DMStagInitialize(bndx, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, M, 0, 0, size, 0, 0, dof0, dof1, 0, 0, stencilType, stencilWidth, lx, NULL, NULL, *dm));
48: PetscFunctionReturn(PETSC_SUCCESS);
49: }
51: PETSC_INTERN PetscErrorCode DMStagRestrictSimple_1d(DM dmf, Vec xf_local, DM dmc, Vec xc_local)
52: {
53: PetscInt Mf, Mc, factorx, dof[2];
54: PetscInt xc, mc, nExtraxc, i, d;
55: PetscInt ileftf, ielemf, ileftc, ielemc;
56: const PetscScalar **arrf;
57: PetscScalar **arrc;
59: PetscFunctionBegin;
60: PetscCall(DMStagGetGlobalSizes(dmf, &Mf, NULL, NULL));
61: PetscCall(DMStagGetGlobalSizes(dmc, &Mc, NULL, NULL));
62: factorx = Mf / Mc;
63: PetscCall(DMStagGetDOF(dmc, &dof[0], &dof[1], NULL, NULL));
65: PetscCall(DMStagGetCorners(dmc, &xc, NULL, NULL, &mc, NULL, NULL, &nExtraxc, NULL, NULL));
66: PetscCall(VecZeroEntries(xc_local));
67: PetscCall(DMStagVecGetArray(dmf, xf_local, &arrf));
68: PetscCall(DMStagVecGetArray(dmc, xc_local, &arrc));
69: PetscCall(DMStagGetLocationSlot(dmf, DMSTAG_LEFT, 0, &ileftf));
70: PetscCall(DMStagGetLocationSlot(dmf, DMSTAG_ELEMENT, 0, &ielemf));
71: PetscCall(DMStagGetLocationSlot(dmc, DMSTAG_LEFT, 0, &ileftc));
72: PetscCall(DMStagGetLocationSlot(dmc, DMSTAG_ELEMENT, 0, &ielemc));
74: for (d = 0; d < dof[0]; ++d)
75: for (i = xc; i < xc + mc + nExtraxc; ++i) arrc[i][ileftc + d] = arrf[factorx * i][ileftf + d];
77: for (d = 0; d < dof[1]; ++d)
78: for (i = xc; i < xc + mc; ++i) {
79: if (factorx % 2 == 0) arrc[i][ielemc + d] = 0.5 * (arrf[factorx * i + factorx / 2 - 1][ielemf + d] + arrf[factorx * i + factorx / 2][ielemf + d]);
80: else arrc[i][ielemc + d] = arrf[factorx * i + factorx / 2][ielemf + d];
81: }
83: PetscCall(DMStagVecRestoreArray(dmf, xf_local, &arrf));
84: PetscCall(DMStagVecRestoreArray(dmc, xc_local, &arrc));
85: PetscFunctionReturn(PETSC_SUCCESS);
86: }
88: PETSC_INTERN PetscErrorCode DMStagSetUniformCoordinatesExplicit_1d(DM dm, PetscReal xmin, PetscReal xmax)
89: {
90: DM_Stag *stagCoord;
91: DM dmCoord;
92: Vec coordLocal;
93: PetscReal h, min;
94: PetscScalar **arr;
95: PetscInt start_ghost, n_ghost, s;
96: PetscInt ileft, ielement;
98: PetscFunctionBegin;
99: PetscCall(DMGetCoordinateDM(dm, &dmCoord));
100: stagCoord = (DM_Stag *)dmCoord->data;
101: for (s = 0; s < 2; ++s) {
102: PetscCheck(stagCoord->dof[s] == 0 || stagCoord->dof[s] == 1, PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Coordinate DM in 1 dimensions must have 0 or 1 dof on each stratum, but stratum %" PetscInt_FMT " has %" PetscInt_FMT " dof", s,
103: stagCoord->dof[s]);
104: }
105: PetscCall(DMCreateLocalVector(dmCoord, &coordLocal));
107: PetscCall(DMStagVecGetArray(dmCoord, coordLocal, &arr));
108: if (stagCoord->dof[0]) PetscCall(DMStagGetLocationSlot(dmCoord, DMSTAG_LEFT, 0, &ileft));
109: if (stagCoord->dof[1]) PetscCall(DMStagGetLocationSlot(dmCoord, DMSTAG_ELEMENT, 0, &ielement));
110: PetscCall(DMStagGetGhostCorners(dmCoord, &start_ghost, NULL, NULL, &n_ghost, NULL, NULL));
112: min = xmin;
113: h = (xmax - xmin) / stagCoord->N[0];
115: for (PetscInt ind = start_ghost; ind < start_ghost + n_ghost; ++ind) {
116: if (stagCoord->dof[0]) {
117: const PetscReal off = 0.0;
118: arr[ind][ileft] = min + ((PetscReal)ind + off) * h;
119: }
120: if (stagCoord->dof[1]) {
121: const PetscReal off = 0.5;
122: arr[ind][ielement] = min + ((PetscReal)ind + off) * h;
123: }
124: }
125: PetscCall(DMStagVecRestoreArray(dmCoord, coordLocal, &arr));
126: PetscCall(DMSetCoordinatesLocal(dm, coordLocal));
127: PetscCall(VecDestroy(&coordLocal));
128: PetscFunctionReturn(PETSC_SUCCESS);
129: }
131: /* Helper functions used in DMSetUp_Stag() */
132: static PetscErrorCode DMStagComputeLocationOffsets_1d(DM);
134: PETSC_INTERN PetscErrorCode DMSetUp_Stag_1d(DM dm)
135: {
136: DM_Stag *const stag = (DM_Stag *)dm->data;
137: PetscMPIInt size, rank;
138: MPI_Comm comm;
140: PetscFunctionBegin;
141: PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
142: PetscCallMPI(MPI_Comm_size(comm, &size));
143: PetscCallMPI(MPI_Comm_rank(comm, &rank));
145: /* Check Global size */
146: PetscCheck(stag->N[0] >= 1, comm, PETSC_ERR_ARG_OUTOFRANGE, "Global grid size of %" PetscInt_FMT " < 1 specified", stag->N[0]);
148: /* Local sizes */
149: PetscCheck(stag->N[0] >= size, comm, PETSC_ERR_ARG_OUTOFRANGE, "More ranks (%d) than elements (%" PetscInt_FMT ") specified", size, stag->N[0]);
150: if (!stag->l[0]) {
151: /* Divide equally, giving an extra elements to higher ranks */
152: PetscCall(PetscMalloc1(stag->nRanks[0], &stag->l[0]));
153: for (PetscInt j = 0; j < stag->nRanks[0]; ++j) stag->l[0][j] = stag->N[0] / stag->nRanks[0] + (stag->N[0] % stag->nRanks[0] > j ? 1 : 0);
154: }
155: {
156: PetscInt Nchk = 0;
157: for (PetscInt j = 0; j < size; ++j) Nchk += stag->l[0][j];
158: PetscCheck(Nchk == stag->N[0], comm, PETSC_ERR_ARG_OUTOFRANGE, "Sum of specified local sizes (%" PetscInt_FMT ") is not equal to global size (%" PetscInt_FMT ")", Nchk, stag->N[0]);
159: }
160: stag->n[0] = stag->l[0][rank];
162: /* Rank (trivial in 1d) */
163: stag->rank[0] = rank;
164: stag->firstRank[0] = (PetscBool)(rank == 0);
165: stag->lastRank[0] = (PetscBool)(rank == size - 1);
167: /* Local (unghosted) numbers of entries */
168: stag->entriesPerElement = stag->dof[0] + stag->dof[1];
169: switch (stag->boundaryType[0]) {
170: case DM_BOUNDARY_NONE:
171: case DM_BOUNDARY_GHOSTED:
172: stag->entries = stag->n[0] * stag->entriesPerElement + (stag->lastRank[0] ? stag->dof[0] : 0);
173: break;
174: case DM_BOUNDARY_PERIODIC:
175: stag->entries = stag->n[0] * stag->entriesPerElement;
176: break;
177: default:
178: SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unsupported x boundary type %s", DMBoundaryTypes[stag->boundaryType[0]]);
179: }
181: /* Starting element */
182: stag->start[0] = 0;
183: for (PetscInt j = 0; j < stag->rank[0]; ++j) stag->start[0] += stag->l[0][j];
185: /* Local/ghosted size and starting element */
186: switch (stag->boundaryType[0]) {
187: case DM_BOUNDARY_NONE:
188: switch (stag->stencilType) {
189: case DMSTAG_STENCIL_NONE: /* Only dummy cells on the right */
190: stag->startGhost[0] = stag->start[0];
191: stag->nGhost[0] = stag->n[0] + (stag->lastRank[0] ? 1 : 0);
192: break;
193: case DMSTAG_STENCIL_STAR:
194: case DMSTAG_STENCIL_BOX:
195: stag->startGhost[0] = stag->firstRank[0] ? stag->start[0] : stag->start[0] - stag->stencilWidth;
196: stag->nGhost[0] = stag->n[0];
197: stag->nGhost[0] += stag->firstRank[0] ? 0 : stag->stencilWidth;
198: stag->nGhost[0] += stag->lastRank[0] ? 1 : stag->stencilWidth;
199: break;
200: default:
201: SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unrecognized ghost stencil type %d", stag->stencilType);
202: }
203: break;
204: case DM_BOUNDARY_GHOSTED:
205: switch (stag->stencilType) {
206: case DMSTAG_STENCIL_NONE:
207: stag->startGhost[0] = stag->start[0];
208: stag->nGhost[0] = stag->n[0] + (stag->lastRank[0] ? 1 : 0);
209: break;
210: case DMSTAG_STENCIL_STAR:
211: case DMSTAG_STENCIL_BOX:
212: stag->startGhost[0] = stag->start[0] - stag->stencilWidth; /* This value may be negative */
213: stag->nGhost[0] = stag->n[0] + 2 * stag->stencilWidth + (stag->lastRank[0] && stag->stencilWidth == 0 ? 1 : 0);
214: break;
215: default:
216: SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unrecognized ghost stencil type %d", stag->stencilType);
217: }
218: break;
219: case DM_BOUNDARY_PERIODIC:
220: switch (stag->stencilType) {
221: case DMSTAG_STENCIL_NONE:
222: stag->startGhost[0] = stag->start[0];
223: stag->nGhost[0] = stag->n[0];
224: break;
225: case DMSTAG_STENCIL_STAR:
226: case DMSTAG_STENCIL_BOX:
227: stag->startGhost[0] = stag->start[0] - stag->stencilWidth; /* This value may be negative */
228: stag->nGhost[0] = stag->n[0] + 2 * stag->stencilWidth;
229: break;
230: default:
231: SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unrecognized ghost stencil type %d", stag->stencilType);
232: }
233: break;
234: default:
235: SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unsupported x boundary type %s", DMBoundaryTypes[stag->boundaryType[0]]);
236: }
238: /* Total size of ghosted/local representation */
239: stag->entriesGhost = stag->nGhost[0] * stag->entriesPerElement;
241: /* Define neighbors */
242: PetscCall(PetscMalloc1(3, &stag->neighbors));
243: if (stag->firstRank[0]) {
244: switch (stag->boundaryType[0]) {
245: case DM_BOUNDARY_GHOSTED:
246: case DM_BOUNDARY_NONE:
247: stag->neighbors[0] = -1;
248: break;
249: case DM_BOUNDARY_PERIODIC:
250: stag->neighbors[0] = stag->nRanks[0] - 1;
251: break;
252: default:
253: SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unsupported x boundary type %s", DMBoundaryTypes[stag->boundaryType[0]]);
254: }
255: } else {
256: stag->neighbors[0] = stag->rank[0] - 1;
257: }
258: stag->neighbors[1] = stag->rank[0];
259: if (stag->lastRank[0]) {
260: switch (stag->boundaryType[0]) {
261: case DM_BOUNDARY_GHOSTED:
262: case DM_BOUNDARY_NONE:
263: stag->neighbors[2] = -1;
264: break;
265: case DM_BOUNDARY_PERIODIC:
266: stag->neighbors[2] = 0;
267: break;
268: default:
269: SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unsupported x boundary type %s", DMBoundaryTypes[stag->boundaryType[0]]);
270: }
271: } else {
272: stag->neighbors[2] = stag->rank[0] + 1;
273: }
275: PetscCheck(stag->n[0] >= stag->stencilWidth, PETSC_COMM_SELF, PETSC_ERR_SUP, "DMStag 1d setup does not support local sizes (%" PetscInt_FMT ") smaller than the elementwise stencil width (%" PetscInt_FMT ")", stag->n[0], stag->stencilWidth);
277: /* Create global->local VecScatter and ISLocalToGlobalMapping */
278: {
279: PetscInt *idxLocal, *idxGlobal, *idxGlobalAll;
280: PetscInt i, iLocal, d, entriesToTransferTotal, ghostOffsetStart, ghostOffsetEnd, nNonDummyGhost;
281: IS isLocal, isGlobal;
283: /* The offset on the right (may not be equal to the stencil width, as we
284: always have at least one ghost element, to account for the boundary
285: point, and may with ghosted boundaries), and the number of non-dummy ghost elements */
286: ghostOffsetStart = stag->start[0] - stag->startGhost[0];
287: ghostOffsetEnd = stag->startGhost[0] + stag->nGhost[0] - (stag->start[0] + stag->n[0]);
288: nNonDummyGhost = stag->nGhost[0] - (stag->lastRank[0] ? ghostOffsetEnd : 0) - (stag->firstRank[0] ? ghostOffsetStart : 0);
290: /* Compute the number of non-dummy entries in the local representation
291: This is equal to the number of non-dummy elements in the local (ghosted) representation,
292: plus some extra entries on the right boundary on the last rank*/
293: switch (stag->boundaryType[0]) {
294: case DM_BOUNDARY_GHOSTED:
295: case DM_BOUNDARY_NONE:
296: entriesToTransferTotal = nNonDummyGhost * stag->entriesPerElement + (stag->lastRank[0] ? stag->dof[0] : 0);
297: break;
298: case DM_BOUNDARY_PERIODIC:
299: entriesToTransferTotal = stag->entriesGhost; /* No dummy points */
300: break;
301: default:
302: SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unsupported x boundary type %s", DMBoundaryTypes[stag->boundaryType[0]]);
303: }
305: PetscCall(PetscMalloc1(entriesToTransferTotal, &idxLocal));
306: PetscCall(PetscMalloc1(entriesToTransferTotal, &idxGlobal));
307: PetscCall(PetscMalloc1(stag->entriesGhost, &idxGlobalAll));
308: if (stag->boundaryType[0] == DM_BOUNDARY_NONE) {
309: PetscInt count = 0, countAll = 0;
310: /* Left ghost points and native points */
311: for (i = stag->startGhost[0], iLocal = 0; iLocal < nNonDummyGhost; ++i, ++iLocal) {
312: for (d = 0; d < stag->entriesPerElement; ++d, ++count, ++countAll) {
313: idxLocal[count] = iLocal * stag->entriesPerElement + d;
314: idxGlobal[count] = i * stag->entriesPerElement + d;
315: idxGlobalAll[countAll] = i * stag->entriesPerElement + d;
316: }
317: }
318: /* Ghost points on the right
319: Special case for last (partial dummy) element on the last rank */
320: if (stag->lastRank[0]) {
321: i = stag->N[0];
322: iLocal = (stag->nGhost[0] - ghostOffsetEnd);
323: /* Only vertex (0-cell) dofs in global representation */
324: for (d = 0; d < stag->dof[0]; ++d, ++count, ++countAll) {
325: idxGlobal[count] = i * stag->entriesPerElement + d;
326: idxLocal[count] = iLocal * stag->entriesPerElement + d;
327: idxGlobalAll[countAll] = i * stag->entriesPerElement + d;
328: }
329: for (d = stag->dof[0]; d < stag->entriesPerElement; ++d, ++countAll) { /* Additional dummy entries */
330: idxGlobalAll[countAll] = -1;
331: }
332: }
333: } else if (stag->boundaryType[0] == DM_BOUNDARY_PERIODIC) {
334: PetscInt count = 0, iLocal = 0; /* No dummy points, so idxGlobal and idxGlobalAll are identical */
335: const PetscInt iMin = stag->firstRank[0] ? stag->start[0] : stag->startGhost[0];
336: const PetscInt iMax = stag->lastRank[0] ? stag->startGhost[0] + stag->nGhost[0] - stag->stencilWidth : stag->startGhost[0] + stag->nGhost[0];
337: /* Ghost points on the left */
338: if (stag->firstRank[0]) {
339: for (i = stag->N[0] - stag->stencilWidth; iLocal < stag->stencilWidth; ++i, ++iLocal) {
340: for (d = 0; d < stag->entriesPerElement; ++d, ++count) {
341: idxGlobal[count] = i * stag->entriesPerElement + d;
342: idxLocal[count] = iLocal * stag->entriesPerElement + d;
343: idxGlobalAll[count] = idxGlobal[count];
344: }
345: }
346: }
347: /* Native points */
348: for (i = iMin; i < iMax; ++i, ++iLocal) {
349: for (d = 0; d < stag->entriesPerElement; ++d, ++count) {
350: idxGlobal[count] = i * stag->entriesPerElement + d;
351: idxLocal[count] = iLocal * stag->entriesPerElement + d;
352: idxGlobalAll[count] = idxGlobal[count];
353: }
354: }
355: /* Ghost points on the right */
356: if (stag->lastRank[0]) {
357: for (i = 0; iLocal < stag->nGhost[0]; ++i, ++iLocal) {
358: for (d = 0; d < stag->entriesPerElement; ++d, ++count) {
359: idxGlobal[count] = i * stag->entriesPerElement + d;
360: idxLocal[count] = iLocal * stag->entriesPerElement + d;
361: idxGlobalAll[count] = idxGlobal[count];
362: }
363: }
364: }
365: } else if (stag->boundaryType[0] == DM_BOUNDARY_GHOSTED) {
366: PetscInt count = 0, countAll = 0;
367: /* Dummy elements on the left, on the first rank */
368: if (stag->firstRank[0]) {
369: for (iLocal = 0; iLocal < ghostOffsetStart; ++iLocal) {
370: /* Complete elements full of dummy entries */
371: for (d = 0; d < stag->entriesPerElement; ++d, ++countAll) idxGlobalAll[countAll] = -1;
372: }
373: i = 0; /* nonDummy entries start with global entry 0 */
374: } else {
375: /* nonDummy entries start as usual */
376: i = stag->startGhost[0];
377: iLocal = 0;
378: }
380: /* non-Dummy entries */
381: {
382: PetscInt iLocalNonDummyMax = stag->firstRank[0] ? nNonDummyGhost + ghostOffsetStart : nNonDummyGhost;
383: for (; iLocal < iLocalNonDummyMax; ++i, ++iLocal) {
384: for (d = 0; d < stag->entriesPerElement; ++d, ++count, ++countAll) {
385: idxLocal[count] = iLocal * stag->entriesPerElement + d;
386: idxGlobal[count] = i * stag->entriesPerElement + d;
387: idxGlobalAll[countAll] = i * stag->entriesPerElement + d;
388: }
389: }
390: }
392: /* (partial) dummy elements on the right, on the last rank */
393: if (stag->lastRank[0]) {
394: /* First one is partial dummy */
395: i = stag->N[0];
396: iLocal = (stag->nGhost[0] - ghostOffsetEnd);
397: for (d = 0; d < stag->dof[0]; ++d, ++count, ++countAll) { /* Only vertex (0-cell) dofs in global representation */
398: idxLocal[count] = iLocal * stag->entriesPerElement + d;
399: idxGlobal[count] = i * stag->entriesPerElement + d;
400: idxGlobalAll[countAll] = i * stag->entriesPerElement + d;
401: }
402: for (d = stag->dof[0]; d < stag->entriesPerElement; ++d, ++countAll) { /* Additional dummy entries */
403: idxGlobalAll[countAll] = -1;
404: }
405: for (iLocal = stag->nGhost[0] - ghostOffsetEnd + 1; iLocal < stag->nGhost[0]; ++iLocal) {
406: /* Additional dummy elements */
407: for (d = 0; d < stag->entriesPerElement; ++d, ++countAll) idxGlobalAll[countAll] = -1;
408: }
409: }
410: } else SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unsupported x boundary type %s", DMBoundaryTypes[stag->boundaryType[0]]);
412: /* Create Local IS (transferring pointer ownership) */
413: PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)dm), entriesToTransferTotal, idxLocal, PETSC_OWN_POINTER, &isLocal));
415: /* Create Global IS (transferring pointer ownership) */
416: PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)dm), entriesToTransferTotal, idxGlobal, PETSC_OWN_POINTER, &isGlobal));
418: /* Create stag->gtol, which doesn't include dummy entries */
419: {
420: Vec local, global;
421: PetscCall(VecCreateMPIWithArray(PetscObjectComm((PetscObject)dm), 1, stag->entries, PETSC_DECIDE, NULL, &global));
422: PetscCall(VecCreateSeqWithArray(PETSC_COMM_SELF, PetscMax(stag->entriesPerElement, 1), stag->entriesGhost, NULL, &local));
423: PetscCall(VecScatterCreate(global, isGlobal, local, isLocal, &stag->gtol));
424: PetscCall(VecDestroy(&global));
425: PetscCall(VecDestroy(&local));
426: }
428: /* In special cases, create a dedicated injective local-to-global map */
429: if (stag->boundaryType[0] == DM_BOUNDARY_PERIODIC && stag->nRanks[0] == 1) PetscCall(DMStagPopulateLocalToGlobalInjective(dm));
431: /* Destroy ISs */
432: PetscCall(ISDestroy(&isLocal));
433: PetscCall(ISDestroy(&isGlobal));
435: /* Create local-to-global map (transferring pointer ownership) */
436: PetscCall(ISLocalToGlobalMappingCreate(comm, 1, stag->entriesGhost, idxGlobalAll, PETSC_OWN_POINTER, &dm->ltogmap));
437: }
439: /* Precompute location offsets */
440: PetscCall(DMStagComputeLocationOffsets_1d(dm));
442: /* View from Options */
443: PetscCall(DMViewFromOptions(dm, NULL, "-dm_view"));
444: PetscFunctionReturn(PETSC_SUCCESS);
445: }
447: static PetscErrorCode DMStagComputeLocationOffsets_1d(DM dm)
448: {
449: DM_Stag *const stag = (DM_Stag *)dm->data;
450: const PetscInt epe = stag->entriesPerElement;
452: PetscFunctionBegin;
453: PetscCall(PetscMalloc1(DMSTAG_NUMBER_LOCATIONS, &stag->locationOffsets));
454: stag->locationOffsets[DMSTAG_LEFT] = 0;
455: stag->locationOffsets[DMSTAG_ELEMENT] = stag->locationOffsets[DMSTAG_LEFT] + stag->dof[0];
456: stag->locationOffsets[DMSTAG_RIGHT] = stag->locationOffsets[DMSTAG_LEFT] + epe;
457: PetscFunctionReturn(PETSC_SUCCESS);
458: }
460: PETSC_INTERN PetscErrorCode DMStagPopulateLocalToGlobalInjective_1d(DM dm)
461: {
462: DM_Stag *const stag = (DM_Stag *)dm->data;
463: PetscInt *idxLocal, *idxGlobal;
464: PetscInt i, iLocal, d, count;
465: IS isLocal, isGlobal;
467: PetscFunctionBegin;
468: PetscCall(PetscMalloc1(stag->entries, &idxLocal));
469: PetscCall(PetscMalloc1(stag->entries, &idxGlobal));
470: count = 0;
471: iLocal = stag->start[0] - stag->startGhost[0];
472: for (i = stag->start[0]; i < stag->start[0] + stag->n[0]; ++i, ++iLocal) {
473: for (d = 0; d < stag->entriesPerElement; ++d, ++count) {
474: idxGlobal[count] = i * stag->entriesPerElement + d;
475: idxLocal[count] = iLocal * stag->entriesPerElement + d;
476: }
477: }
478: if (stag->lastRank[0] && stag->boundaryType[0] != DM_BOUNDARY_PERIODIC) {
479: i = stag->start[0] + stag->n[0];
480: iLocal = stag->start[0] - stag->startGhost[0] + stag->n[0];
481: for (d = 0; d < stag->dof[0]; ++d, ++count) {
482: idxGlobal[count] = i * stag->entriesPerElement + d;
483: idxLocal[count] = iLocal * stag->entriesPerElement + d;
484: }
485: }
486: PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)dm), stag->entries, idxLocal, PETSC_OWN_POINTER, &isLocal));
487: PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)dm), stag->entries, idxGlobal, PETSC_OWN_POINTER, &isGlobal));
488: {
489: Vec local, global;
490: PetscCall(VecCreateMPIWithArray(PetscObjectComm((PetscObject)dm), 1, stag->entries, PETSC_DECIDE, NULL, &global));
491: PetscCall(VecCreateSeqWithArray(PETSC_COMM_SELF, PetscMax(stag->entriesPerElement, 1), stag->entriesGhost, NULL, &local));
492: PetscCall(VecScatterCreate(local, isLocal, global, isGlobal, &stag->ltog_injective));
493: PetscCall(VecDestroy(&global));
494: PetscCall(VecDestroy(&local));
495: }
496: PetscCall(ISDestroy(&isLocal));
497: PetscCall(ISDestroy(&isGlobal));
498: PetscFunctionReturn(PETSC_SUCCESS);
499: }
501: PETSC_INTERN PetscErrorCode DMStagPopulateLocalToLocal1d_Internal(DM dm)
502: {
503: DM_Stag *const stag = (DM_Stag *)dm->data;
504: PetscInt *idxRemap;
505: PetscInt leftGhostEntries;
507: PetscFunctionBegin;
508: PetscCall(VecScatterCopy(stag->gtol, &stag->ltol));
509: PetscCall(PetscMalloc1(stag->entries, &idxRemap));
511: leftGhostEntries = (stag->start[0] - stag->startGhost[0]) * stag->entriesPerElement;
512: for (PetscInt i = 0; i < stag->entries; ++i) idxRemap[i] = leftGhostEntries + i;
514: PetscCall(VecScatterRemap(stag->ltol, idxRemap, NULL));
515: PetscCall(PetscFree(idxRemap));
516: PetscFunctionReturn(PETSC_SUCCESS);
517: }
519: PETSC_INTERN PetscErrorCode DMCreateMatrix_Stag_1D_AIJ_Assemble(DM dm, Mat A)
520: {
521: DMStagStencilType stencil_type;
522: PetscInt dof[2], start, n, n_extra, stencil_width, N, epe;
523: DMBoundaryType boundary_type_x;
525: PetscFunctionBegin;
526: PetscCall(DMStagGetDOF(dm, &dof[0], &dof[1], NULL, NULL));
527: PetscCall(DMStagGetStencilType(dm, &stencil_type));
528: PetscCall(DMStagGetStencilWidth(dm, &stencil_width));
529: PetscCall(DMStagGetCorners(dm, &start, NULL, NULL, &n, NULL, NULL, &n_extra, NULL, NULL));
530: PetscCall(DMStagGetGlobalSizes(dm, &N, NULL, NULL));
531: PetscCall(DMStagGetEntriesPerElement(dm, &epe));
532: PetscCall(DMStagGetBoundaryTypes(dm, &boundary_type_x, NULL, NULL));
533: if (stencil_type == DMSTAG_STENCIL_NONE) {
534: /* Couple all DOF at each location to each other */
535: DMStagStencil *row_vertex, *row_element;
537: PetscCall(PetscMalloc1(dof[0], &row_vertex));
538: for (PetscInt c = 0; c < dof[0]; ++c) {
539: row_vertex[c].loc = DMSTAG_LEFT;
540: row_vertex[c].c = c;
541: }
543: PetscCall(PetscMalloc1(dof[1], &row_element));
544: for (PetscInt c = 0; c < dof[1]; ++c) {
545: row_element[c].loc = DMSTAG_ELEMENT;
546: row_element[c].c = c;
547: }
549: for (PetscInt e = start; e < start + n + n_extra; ++e) {
550: {
551: for (PetscInt c = 0; c < dof[0]; ++c) row_vertex[c].i = e;
552: PetscCall(DMStagMatSetValuesStencil(dm, A, dof[0], row_vertex, dof[0], row_vertex, NULL, INSERT_VALUES));
553: }
554: if (e < N) {
555: for (PetscInt c = 0; c < dof[1]; ++c) row_element[c].i = e;
556: PetscCall(DMStagMatSetValuesStencil(dm, A, dof[1], row_element, dof[1], row_element, NULL, INSERT_VALUES));
557: }
558: }
559: PetscCall(PetscFree(row_vertex));
560: PetscCall(PetscFree(row_element));
561: } else if (stencil_type == DMSTAG_STENCIL_STAR || stencil_type == DMSTAG_STENCIL_BOX) {
562: DMStagStencil *col, *row;
564: PetscCall(PetscMalloc1(epe, &row));
565: {
566: PetscInt nrows = 0;
567: for (PetscInt c = 0; c < dof[0]; ++c) {
568: row[nrows].c = c;
569: row[nrows].loc = DMSTAG_LEFT;
570: ++nrows;
571: }
572: for (PetscInt c = 0; c < dof[1]; ++c) {
573: row[nrows].c = c;
574: row[nrows].loc = DMSTAG_ELEMENT;
575: ++nrows;
576: }
577: }
578: PetscCall(PetscMalloc1(epe, &col));
579: {
580: PetscInt ncols = 0;
581: for (PetscInt c = 0; c < dof[0]; ++c) {
582: col[ncols].c = c;
583: col[ncols].loc = DMSTAG_LEFT;
584: ++ncols;
585: }
586: for (PetscInt c = 0; c < dof[1]; ++c) {
587: col[ncols].c = c;
588: col[ncols].loc = DMSTAG_ELEMENT;
589: ++ncols;
590: }
591: }
592: for (PetscInt e = start; e < start + n + n_extra; ++e) {
593: for (PetscInt i = 0; i < epe; ++i) row[i].i = e;
594: for (PetscInt offset = -stencil_width; offset <= stencil_width; ++offset) {
595: const PetscInt e_offset = e + offset;
597: /* Only set values corresponding to elements which can have non-dummy entries,
598: meaning those that map to unknowns in the global representation. In the periodic
599: case, this is the entire stencil, but in all other cases, only includes a single
600: "extra" element which is partially outside the physical domain (those points in the
601: global representation */
602: if (boundary_type_x == DM_BOUNDARY_PERIODIC || (e_offset < N + 1 && e_offset >= 0)) {
603: for (PetscInt i = 0; i < epe; ++i) col[i].i = e_offset;
604: PetscCall(DMStagMatSetValuesStencil(dm, A, epe, row, epe, col, NULL, INSERT_VALUES));
605: }
606: }
607: }
608: PetscCall(PetscFree(row));
609: PetscCall(PetscFree(col));
610: } else SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Unsupported stencil type %s", DMStagStencilTypes[stencil_type]);
611: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
612: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
613: PetscFunctionReturn(PETSC_SUCCESS);
614: }