Actual source code: dagetelem.c
2: #include <petsc/private/dmdaimpl.h>
4: static PetscErrorCode DMDAGetElements_1D(DM dm, PetscInt *nel, PetscInt *nen, const PetscInt *e[])
5: {
6: DM_DA *da = (DM_DA *)dm->data;
7: PetscInt i, xs, xe, Xs, Xe;
8: PetscInt cnt = 0;
10: if (!da->e) {
11: PetscInt corners[2];
14: DMDAGetCorners(dm, &xs, NULL, NULL, &xe, NULL, NULL);
15: DMDAGetGhostCorners(dm, &Xs, NULL, NULL, &Xe, NULL, NULL);
16: xe += xs;
17: Xe += Xs;
18: if (xs != Xs) xs -= 1;
19: da->ne = 1 * (xe - xs - 1);
20: PetscMalloc1(1 + 2 * da->ne, &da->e);
21: for (i = xs; i < xe - 1; i++) {
22: da->e[cnt++] = (i - Xs);
23: da->e[cnt++] = (i - Xs + 1);
24: }
25: da->nen = 2;
27: corners[0] = (xs - Xs);
28: corners[1] = (xe - 1 - Xs);
29: ISCreateGeneral(PETSC_COMM_SELF, 2, corners, PETSC_COPY_VALUES, &da->ecorners);
30: }
31: *nel = da->ne;
32: *nen = da->nen;
33: *e = da->e;
34: return 0;
35: }
37: static PetscErrorCode DMDAGetElements_2D(DM dm, PetscInt *nel, PetscInt *nen, const PetscInt *e[])
38: {
39: DM_DA *da = (DM_DA *)dm->data;
40: PetscInt i, xs, xe, Xs, Xe;
41: PetscInt j, ys, ye, Ys, Ye;
42: PetscInt cnt = 0, cell[4], ns = 2;
43: PetscInt c, split[] = {0, 1, 3, 2, 3, 1};
45: if (!da->e) {
46: PetscInt corners[4], nn = 0;
50: switch (da->elementtype) {
51: case DMDA_ELEMENT_Q1:
52: da->nen = 4;
53: break;
54: case DMDA_ELEMENT_P1:
55: da->nen = 3;
56: break;
57: default:
58: SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unknown element type %d", da->elementtype);
59: }
60: nn = da->nen;
62: if (da->elementtype == DMDA_ELEMENT_P1) ns = 2;
63: if (da->elementtype == DMDA_ELEMENT_Q1) ns = 1;
64: DMDAGetCorners(dm, &xs, &ys, NULL, &xe, &ye, NULL);
65: DMDAGetGhostCorners(dm, &Xs, &Ys, NULL, &Xe, &Ye, NULL);
66: xe += xs;
67: Xe += Xs;
68: if (xs != Xs) xs -= 1;
69: ye += ys;
70: Ye += Ys;
71: if (ys != Ys) ys -= 1;
72: da->ne = ns * (xe - xs - 1) * (ye - ys - 1);
73: PetscMalloc1(1 + nn * da->ne, &da->e);
74: for (j = ys; j < ye - 1; j++) {
75: for (i = xs; i < xe - 1; i++) {
76: cell[0] = (i - Xs) + (j - Ys) * (Xe - Xs);
77: cell[1] = (i - Xs + 1) + (j - Ys) * (Xe - Xs);
78: cell[2] = (i - Xs + 1) + (j - Ys + 1) * (Xe - Xs);
79: cell[3] = (i - Xs) + (j - Ys + 1) * (Xe - Xs);
80: if (da->elementtype == DMDA_ELEMENT_P1) {
81: for (c = 0; c < ns * nn; c++) da->e[cnt++] = cell[split[c]];
82: }
83: if (da->elementtype == DMDA_ELEMENT_Q1) {
84: for (c = 0; c < ns * nn; c++) da->e[cnt++] = cell[c];
85: }
86: }
87: }
89: corners[0] = (xs - Xs) + (ys - Ys) * (Xe - Xs);
90: corners[1] = (xe - 1 - Xs) + (ys - Ys) * (Xe - Xs);
91: corners[2] = (xs - Xs) + (ye - 1 - Ys) * (Xe - Xs);
92: corners[3] = (xe - 1 - Xs) + (ye - 1 - Ys) * (Xe - Xs);
93: ISCreateGeneral(PETSC_COMM_SELF, 4, corners, PETSC_COPY_VALUES, &da->ecorners);
94: }
95: *nel = da->ne;
96: *nen = da->nen;
97: *e = da->e;
98: return 0;
99: }
101: static PetscErrorCode DMDAGetElements_3D(DM dm, PetscInt *nel, PetscInt *nen, const PetscInt *e[])
102: {
103: DM_DA *da = (DM_DA *)dm->data;
104: PetscInt i, xs, xe, Xs, Xe;
105: PetscInt j, ys, ye, Ys, Ye;
106: PetscInt k, zs, ze, Zs, Ze;
107: PetscInt cnt = 0, cell[8], ns = 6;
108: PetscInt c, split[] = {0, 1, 3, 7, 0, 1, 7, 4, 1, 2, 3, 7, 1, 2, 7, 6, 1, 4, 5, 7, 1, 5, 6, 7};
110: if (!da->e) {
111: PetscInt corners[8], nn = 0;
115: switch (da->elementtype) {
116: case DMDA_ELEMENT_Q1:
117: da->nen = 8;
118: break;
119: case DMDA_ELEMENT_P1:
120: da->nen = 4;
121: break;
122: default:
123: SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unknown element type %d", da->elementtype);
124: }
125: nn = da->nen;
127: if (da->elementtype == DMDA_ELEMENT_P1) ns = 6;
128: if (da->elementtype == DMDA_ELEMENT_Q1) ns = 1;
129: DMDAGetCorners(dm, &xs, &ys, &zs, &xe, &ye, &ze);
130: DMDAGetGhostCorners(dm, &Xs, &Ys, &Zs, &Xe, &Ye, &Ze);
131: xe += xs;
132: Xe += Xs;
133: if (xs != Xs) xs -= 1;
134: ye += ys;
135: Ye += Ys;
136: if (ys != Ys) ys -= 1;
137: ze += zs;
138: Ze += Zs;
139: if (zs != Zs) zs -= 1;
140: da->ne = ns * (xe - xs - 1) * (ye - ys - 1) * (ze - zs - 1);
141: PetscMalloc1(1 + nn * da->ne, &da->e);
142: for (k = zs; k < ze - 1; k++) {
143: for (j = ys; j < ye - 1; j++) {
144: for (i = xs; i < xe - 1; i++) {
145: cell[0] = (i - Xs) + (j - Ys) * (Xe - Xs) + (k - Zs) * (Xe - Xs) * (Ye - Ys);
146: cell[1] = (i + 1 - Xs) + (j - Ys) * (Xe - Xs) + (k - Zs) * (Xe - Xs) * (Ye - Ys);
147: cell[2] = (i + 1 - Xs) + (j + 1 - Ys) * (Xe - Xs) + (k - Zs) * (Xe - Xs) * (Ye - Ys);
148: cell[3] = (i - Xs) + (j + 1 - Ys) * (Xe - Xs) + (k - Zs) * (Xe - Xs) * (Ye - Ys);
149: cell[4] = (i - Xs) + (j - Ys) * (Xe - Xs) + (k + 1 - Zs) * (Xe - Xs) * (Ye - Ys);
150: cell[5] = (i + 1 - Xs) + (j - Ys) * (Xe - Xs) + (k + 1 - Zs) * (Xe - Xs) * (Ye - Ys);
151: cell[6] = (i + 1 - Xs) + (j + 1 - Ys) * (Xe - Xs) + (k + 1 - Zs) * (Xe - Xs) * (Ye - Ys);
152: cell[7] = (i - Xs) + (j + 1 - Ys) * (Xe - Xs) + (k + 1 - Zs) * (Xe - Xs) * (Ye - Ys);
153: if (da->elementtype == DMDA_ELEMENT_P1) {
154: for (c = 0; c < ns * nn; c++) da->e[cnt++] = cell[split[c]];
155: }
156: if (da->elementtype == DMDA_ELEMENT_Q1) {
157: for (c = 0; c < ns * nn; c++) da->e[cnt++] = cell[c];
158: }
159: }
160: }
161: }
163: corners[0] = (xs - Xs) + (ys - Ys) * (Xe - Xs) + (zs - Zs) * (Xe - Xs) * (Ye - Ys);
164: corners[1] = (xe - 1 - Xs) + (ys - Ys) * (Xe - Xs) + (zs - Zs) * (Xe - Xs) * (Ye - Ys);
165: corners[2] = (xs - Xs) + (ye - 1 - Ys) * (Xe - Xs) + (zs - Zs) * (Xe - Xs) * (Ye - Ys);
166: corners[3] = (xe - 1 - Xs) + (ye - 1 - Ys) * (Xe - Xs) + (zs - Zs) * (Xe - Xs) * (Ye - Ys);
167: corners[4] = (xs - Xs) + (ys - Ys) * (Xe - Xs) + (ze - 1 - Zs) * (Xe - Xs) * (Ye - Ys);
168: corners[5] = (xe - 1 - Xs) + (ys - Ys) * (Xe - Xs) + (ze - 1 - Zs) * (Xe - Xs) * (Ye - Ys);
169: corners[6] = (xs - Xs) + (ye - 1 - Ys) * (Xe - Xs) + (ze - 1 - Zs) * (Xe - Xs) * (Ye - Ys);
170: corners[7] = (xe - 1 - Xs) + (ye - 1 - Ys) * (Xe - Xs) + (ze - 1 - Zs) * (Xe - Xs) * (Ye - Ys);
171: ISCreateGeneral(PETSC_COMM_SELF, 8, corners, PETSC_COPY_VALUES, &da->ecorners);
172: }
173: *nel = da->ne;
174: *nen = da->nen;
175: *e = da->e;
176: return 0;
177: }
179: /*@
180: DMDAGetElementsCorners - Returns the global (x,y,z) indices of the lower left
181: corner of the non-overlapping decomposition identified by DMDAGetElements()
183: Not Collective
185: Input Parameter:
186: . da - the DM object
188: Output Parameters:
189: + gx - the x index
190: . gy - the y index
191: - gz - the z index
193: Level: intermediate
195: Notes:
197: .seealso: `DMDAElementType`, `DMDASetElementType()`, `DMDAGetElements()`
198: @*/
199: PetscErrorCode DMDAGetElementsCorners(DM da, PetscInt *gx, PetscInt *gy, PetscInt *gz)
200: {
201: PetscInt xs, Xs;
202: PetscInt ys, Ys;
203: PetscInt zs, Zs;
204: PetscBool isda;
210: PetscObjectTypeCompare((PetscObject)da, DMDA, &isda);
212: DMDAGetCorners(da, &xs, &ys, &zs, NULL, NULL, NULL);
213: DMDAGetGhostCorners(da, &Xs, &Ys, &Zs, NULL, NULL, NULL);
214: if (xs != Xs) xs -= 1;
215: if (ys != Ys) ys -= 1;
216: if (zs != Zs) zs -= 1;
217: if (gx) *gx = xs;
218: if (gy) *gy = ys;
219: if (gz) *gz = zs;
220: return 0;
221: }
223: /*@
224: DMDAGetElementsSizes - Gets the local number of elements per direction for the non-overlapping decomposition identified by DMDAGetElements()
226: Not Collective
228: Input Parameter:
229: . da - the DM object
231: Output Parameters:
232: + mx - number of local elements in x-direction
233: . my - number of local elements in y-direction
234: - mz - number of local elements in z-direction
236: Level: intermediate
238: Notes:
239: It returns the same number of elements, irrespective of the DMDAElementType
241: .seealso: `DMDAElementType`, `DMDASetElementType()`, `DMDAGetElements`
242: @*/
243: PetscErrorCode DMDAGetElementsSizes(DM da, PetscInt *mx, PetscInt *my, PetscInt *mz)
244: {
245: PetscInt xs, xe, Xs;
246: PetscInt ys, ye, Ys;
247: PetscInt zs, ze, Zs;
248: PetscInt dim;
249: PetscBool isda;
255: PetscObjectTypeCompare((PetscObject)da, DMDA, &isda);
257: DMDAGetCorners(da, &xs, &ys, &zs, &xe, &ye, &ze);
258: DMDAGetGhostCorners(da, &Xs, &Ys, &Zs, NULL, NULL, NULL);
259: xe += xs;
260: if (xs != Xs) xs -= 1;
261: ye += ys;
262: if (ys != Ys) ys -= 1;
263: ze += zs;
264: if (zs != Zs) zs -= 1;
265: if (mx) *mx = 0;
266: if (my) *my = 0;
267: if (mz) *mz = 0;
268: DMGetDimension(da, &dim);
269: switch (dim) {
270: case 3:
271: if (mz) *mz = ze - zs - 1; /* fall through */
272: case 2:
273: if (my) *my = ye - ys - 1; /* fall through */
274: case 1:
275: if (mx) *mx = xe - xs - 1;
276: break;
277: }
278: return 0;
279: }
281: /*@
282: DMDASetElementType - Sets the element type to be returned by DMDAGetElements()
284: Not Collective
286: Input Parameter:
287: . da - the DMDA object
289: Output Parameters:
290: . etype - the element type, currently either DMDA_ELEMENT_P1 or DMDA_ELEMENT_Q1
292: Level: intermediate
294: .seealso: `DMDAElementType`, `DMDAGetElementType()`, `DMDAGetElements()`, `DMDARestoreElements()`
295: @*/
296: PetscErrorCode DMDASetElementType(DM da, DMDAElementType etype)
297: {
298: DM_DA *dd = (DM_DA *)da->data;
299: PetscBool isda;
303: PetscObjectTypeCompare((PetscObject)da, DMDA, &isda);
304: if (!isda) return 0;
305: if (dd->elementtype != etype) {
306: PetscFree(dd->e);
307: ISDestroy(&dd->ecorners);
309: dd->elementtype = etype;
310: dd->ne = 0;
311: dd->nen = 0;
312: dd->e = NULL;
313: }
314: return 0;
315: }
317: /*@
318: DMDAGetElementType - Gets the element type to be returned by DMDAGetElements()
320: Not Collective
322: Input Parameter:
323: . da - the DMDA object
325: Output Parameters:
326: . etype - the element type, currently either DMDA_ELEMENT_P1 or DMDA_ELEMENT_Q1
328: Level: intermediate
330: .seealso: `DMDAElementType`, `DMDASetElementType()`, `DMDAGetElements()`, `DMDARestoreElements()`
331: @*/
332: PetscErrorCode DMDAGetElementType(DM da, DMDAElementType *etype)
333: {
334: DM_DA *dd = (DM_DA *)da->data;
335: PetscBool isda;
339: PetscObjectTypeCompare((PetscObject)da, DMDA, &isda);
341: *etype = dd->elementtype;
342: return 0;
343: }
345: /*@C
346: DMDAGetElements - Gets an array containing the indices (in local coordinates)
347: of all the local elements
349: Not Collective
351: Input Parameter:
352: . dm - the DM object
354: Output Parameters:
355: + nel - number of local elements
356: . nen - number of element nodes
357: - e - the local indices of the elements' vertices
359: Level: intermediate
361: Notes:
362: Call DMDARestoreElements() once you have finished accessing the elements.
364: Each process uniquely owns a subset of the elements. That is no element is owned by two or more processes.
366: If on each process you integrate over its owned elements and use ADD_VALUES in Vec/MatSetValuesLocal() then you'll obtain the correct result.
368: Not supported in Fortran
370: .seealso: `DMDAElementType`, `DMDASetElementType()`, `VecSetValuesLocal()`, `MatSetValuesLocal()`, `DMGlobalToLocalBegin()`, `DMLocalToGlobalBegin()`
371: @*/
372: PetscErrorCode DMDAGetElements(DM dm, PetscInt *nel, PetscInt *nen, const PetscInt *e[])
373: {
374: PetscInt dim;
375: DM_DA *dd = (DM_DA *)dm->data;
376: PetscBool isda;
382: PetscObjectTypeCompare((PetscObject)dm, DMDA, &isda);
385: DMGetDimension(dm, &dim);
386: if (dd->e) {
387: *nel = dd->ne;
388: *nen = dd->nen;
389: *e = dd->e;
390: return 0;
391: }
392: if (dim == -1) {
393: *nel = 0;
394: *nen = 0;
395: *e = NULL;
396: } else if (dim == 1) {
397: DMDAGetElements_1D(dm, nel, nen, e);
398: } else if (dim == 2) {
399: DMDAGetElements_2D(dm, nel, nen, e);
400: } else if (dim == 3) {
401: DMDAGetElements_3D(dm, nel, nen, e);
402: } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_CORRUPT, "DMDA dimension not 1, 2, or 3, it is %" PetscInt_FMT, dim);
403: return 0;
404: }
406: /*@
407: DMDAGetSubdomainCornersIS - Gets an index set containing the corner indices (in local coordinates)
408: of the non-overlapping decomposition identified by DMDAGetElements
410: Not Collective
412: Input Parameter:
413: . dm - the DM object
415: Output Parameters:
416: . is - the index set
418: Level: intermediate
420: Notes:
421: Call DMDARestoreSubdomainCornersIS() once you have finished accessing the index set.
423: .seealso: `DMDAElementType`, `DMDASetElementType()`, `DMDAGetElements()`, `DMDARestoreElementsCornersIS()`
424: @*/
425: PetscErrorCode DMDAGetSubdomainCornersIS(DM dm, IS *is)
426: {
427: DM_DA *dd = (DM_DA *)dm->data;
428: PetscBool isda;
432: PetscObjectTypeCompare((PetscObject)dm, DMDA, &isda);
435: if (!dd->ecorners) { /* compute elements if not yet done */
436: const PetscInt *e;
437: PetscInt nel, nen;
439: DMDAGetElements(dm, &nel, &nen, &e);
440: DMDARestoreElements(dm, &nel, &nen, &e);
441: }
442: *is = dd->ecorners;
443: return 0;
444: }
446: /*@C
447: DMDARestoreElements - Restores the array obtained with DMDAGetElements()
449: Not Collective
451: Input Parameters:
452: + dm - the DM object
453: . nel - number of local elements
454: . nen - number of element nodes
455: - e - the local indices of the elements' vertices
457: Level: intermediate
459: Note: You should not access these values after you have called this routine.
461: This restore signals the DMDA object that you no longer need access to the array information.
463: Not supported in Fortran
465: .seealso: `DMDAElementType`, `DMDASetElementType()`, `DMDAGetElements()`
466: @*/
467: PetscErrorCode DMDARestoreElements(DM dm, PetscInt *nel, PetscInt *nen, const PetscInt *e[])
468: {
473: *nel = 0;
474: *nen = -1;
475: *e = NULL;
476: return 0;
477: }
479: /*@
480: DMDARestoreSubdomainCornersIS - Restores the IS obtained with DMDAGetSubdomainCornersIS()
482: Not Collective
484: Input Parameters:
485: + dm - the DM object
486: - is - the index set
488: Level: intermediate
490: Note:
492: .seealso: `DMDAElementType`, `DMDASetElementType()`, `DMDAGetSubdomainCornersIS()`
493: @*/
494: PetscErrorCode DMDARestoreSubdomainCornersIS(DM dm, IS *is)
495: {
498: *is = NULL;
499: return 0;
500: }