Actual source code: da1.c


  2: /*
  3:    Code for manipulating distributed regular 1d arrays in parallel.
  4:    This file was created by Peter Mell   6/30/95
  5: */

  7: #include <petsc/private/dmdaimpl.h>

  9: #include <petscdraw.h>
 10: static PetscErrorCode DMView_DA_1d(DM da, PetscViewer viewer)
 11: {
 12:   PetscMPIInt rank;
 13:   PetscBool   iascii, isdraw, isglvis, isbinary;
 14:   DM_DA      *dd = (DM_DA *)da->data;
 15: #if defined(PETSC_HAVE_MATLAB)
 16:   PetscBool ismatlab;
 17: #endif

 19:   PetscFunctionBegin;
 20:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)da), &rank));

 22:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
 23:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
 24:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERGLVIS, &isglvis));
 25:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
 26: #if defined(PETSC_HAVE_MATLAB)
 27:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERMATLAB, &ismatlab));
 28: #endif
 29:   if (iascii) {
 30:     PetscViewerFormat format;

 32:     PetscCall(PetscViewerGetFormat(viewer, &format));
 33:     if (format == PETSC_VIEWER_LOAD_BALANCE) {
 34:       PetscInt      i, nmax = 0, nmin = PETSC_MAX_INT, navg = 0, *nz, nzlocal;
 35:       DMDALocalInfo info;
 36:       PetscMPIInt   size;
 37:       PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)da), &size));
 38:       PetscCall(DMDAGetLocalInfo(da, &info));
 39:       nzlocal = info.xm;
 40:       PetscCall(PetscMalloc1(size, &nz));
 41:       PetscCallMPI(MPI_Allgather(&nzlocal, 1, MPIU_INT, nz, 1, MPIU_INT, PetscObjectComm((PetscObject)da)));
 42:       for (i = 0; i < (PetscInt)size; i++) {
 43:         nmax = PetscMax(nmax, nz[i]);
 44:         nmin = PetscMin(nmin, nz[i]);
 45:         navg += nz[i];
 46:       }
 47:       PetscCall(PetscFree(nz));
 48:       navg = navg / size;
 49:       PetscCall(PetscViewerASCIIPrintf(viewer, "  Load Balance - Grid Points: Min %" PetscInt_FMT "  avg %" PetscInt_FMT "  max %" PetscInt_FMT "\n", nmin, navg, nmax));
 50:       PetscFunctionReturn(PETSC_SUCCESS);
 51:     }
 52:     if (format != PETSC_VIEWER_ASCII_VTK_DEPRECATED && format != PETSC_VIEWER_ASCII_VTK_CELL_DEPRECATED && format != PETSC_VIEWER_ASCII_GLVIS) {
 53:       DMDALocalInfo info;
 54:       PetscCall(DMDAGetLocalInfo(da, &info));
 55:       PetscCall(PetscViewerASCIIPushSynchronized(viewer));
 56:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "Processor [%d] M %" PetscInt_FMT " m %" PetscInt_FMT " w %" PetscInt_FMT " s %" PetscInt_FMT "\n", rank, dd->M, dd->m, dd->w, dd->s));
 57:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "X range of indices: %" PetscInt_FMT " %" PetscInt_FMT "\n", info.xs, info.xs + info.xm));
 58:       PetscCall(PetscViewerFlush(viewer));
 59:       PetscCall(PetscViewerASCIIPopSynchronized(viewer));
 60:     } else if (format == PETSC_VIEWER_ASCII_GLVIS) PetscCall(DMView_DA_GLVis(da, viewer));
 61:     else PetscCall(DMView_DA_VTK(da, viewer));
 62:   } else if (isdraw) {
 63:     PetscDraw draw;
 64:     double    ymin = -1, ymax = 1, xmin = -1, xmax = dd->M, x;
 65:     PetscInt  base;
 66:     char      node[10];
 67:     PetscBool isnull;

 69:     PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
 70:     PetscCall(PetscDrawIsNull(draw, &isnull));
 71:     if (isnull) PetscFunctionReturn(PETSC_SUCCESS);

 73:     PetscCall(PetscDrawCheckResizedWindow(draw));
 74:     PetscCall(PetscDrawClear(draw));
 75:     PetscCall(PetscDrawSetCoordinates(draw, xmin, ymin, xmax, ymax));

 77:     PetscDrawCollectiveBegin(draw);
 78:     /* first processor draws all node lines */
 79:     if (rank == 0) {
 80:       PetscInt xmin_tmp;
 81:       ymin = 0.0;
 82:       ymax = 0.3;
 83:       for (xmin_tmp = 0; xmin_tmp < dd->M; xmin_tmp++) PetscCall(PetscDrawLine(draw, (double)xmin_tmp, ymin, (double)xmin_tmp, ymax, PETSC_DRAW_BLACK));
 84:       xmin = 0.0;
 85:       xmax = dd->M - 1;
 86:       PetscCall(PetscDrawLine(draw, xmin, ymin, xmax, ymin, PETSC_DRAW_BLACK));
 87:       PetscCall(PetscDrawLine(draw, xmin, ymax, xmax, ymax, PETSC_DRAW_BLACK));
 88:     }
 89:     PetscDrawCollectiveEnd(draw);
 90:     PetscCall(PetscDrawFlush(draw));
 91:     PetscCall(PetscDrawPause(draw));

 93:     PetscDrawCollectiveBegin(draw);
 94:     /* draw my box */
 95:     ymin = 0;
 96:     ymax = 0.3;
 97:     xmin = dd->xs / dd->w;
 98:     xmax = (dd->xe / dd->w) - 1;
 99:     PetscCall(PetscDrawLine(draw, xmin, ymin, xmax, ymin, PETSC_DRAW_RED));
100:     PetscCall(PetscDrawLine(draw, xmin, ymin, xmin, ymax, PETSC_DRAW_RED));
101:     PetscCall(PetscDrawLine(draw, xmin, ymax, xmax, ymax, PETSC_DRAW_RED));
102:     PetscCall(PetscDrawLine(draw, xmax, ymin, xmax, ymax, PETSC_DRAW_RED));
103:     /* Put in index numbers */
104:     base = dd->base / dd->w;
105:     for (x = xmin; x <= xmax; x++) {
106:       PetscCall(PetscSNPrintf(node, sizeof(node), "%d", (int)base++));
107:       PetscCall(PetscDrawString(draw, x, ymin, PETSC_DRAW_RED, node));
108:     }
109:     PetscDrawCollectiveEnd(draw);
110:     PetscCall(PetscDrawFlush(draw));
111:     PetscCall(PetscDrawPause(draw));
112:     PetscCall(PetscDrawSave(draw));
113:   } else if (isglvis) {
114:     PetscCall(DMView_DA_GLVis(da, viewer));
115:   } else if (isbinary) {
116:     PetscCall(DMView_DA_Binary(da, viewer));
117: #if defined(PETSC_HAVE_MATLAB)
118:   } else if (ismatlab) {
119:     PetscCall(DMView_DA_Matlab(da, viewer));
120: #endif
121:   }
122:   PetscFunctionReturn(PETSC_SUCCESS);
123: }

125: PetscErrorCode DMSetUp_DA_1D(DM da)
126: {
127:   DM_DA          *dd    = (DM_DA *)da->data;
128:   const PetscInt  M     = dd->M;
129:   const PetscInt  dof   = dd->w;
130:   const PetscInt  s     = dd->s;
131:   const PetscInt  sDist = s; /* stencil distance in points */
132:   const PetscInt *lx    = dd->lx;
133:   DMBoundaryType  bx    = dd->bx;
134:   MPI_Comm        comm;
135:   Vec             local, global;
136:   VecScatter      gtol;
137:   IS              to, from;
138:   PetscBool       flg1 = PETSC_FALSE, flg2 = PETSC_FALSE;
139:   PetscMPIInt     rank, size;
140:   PetscInt        i, *idx, nn, left, xs, xe, x, Xs, Xe, start, m, IXs, IXe;

142:   PetscFunctionBegin;
143:   PetscCall(PetscObjectGetComm((PetscObject)da, &comm));
144:   PetscCallMPI(MPI_Comm_size(comm, &size));
145:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

147:   dd->p = 1;
148:   dd->n = 1;
149:   dd->m = size;
150:   m     = dd->m;

152:   if (s > 0) {
153:     /* if not communicating data then should be ok to have nothing on some processes */
154:     PetscCheck(M >= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "More processes than data points! %" PetscInt_FMT " %" PetscInt_FMT, m, M);
155:     PetscCheck((M - 1) >= s || size <= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Array is too small for stencil! %" PetscInt_FMT " %" PetscInt_FMT, M - 1, s);
156:   }

158:   /*
159:      Determine locally owned region
160:      xs is the first local node number, x is the number of local nodes
161:   */
162:   if (!lx) {
163:     PetscCall(PetscMalloc1(m, &dd->lx));
164:     PetscCall(PetscOptionsGetBool(((PetscObject)da)->options, ((PetscObject)da)->prefix, "-da_partition_blockcomm", &flg1, NULL));
165:     PetscCall(PetscOptionsGetBool(((PetscObject)da)->options, ((PetscObject)da)->prefix, "-da_partition_nodes_at_end", &flg2, NULL));
166:     if (flg1) { /* Block Comm type Distribution */
167:       xs = rank * M / m;
168:       x  = (rank + 1) * M / m - xs;
169:     } else if (flg2) { /* The odd nodes are evenly distributed across last nodes */
170:       x = (M + rank) / m;
171:       if (M / m == x) xs = rank * x;
172:       else xs = rank * (x - 1) + (M + rank) % (x * m);
173:     } else { /* The odd nodes are evenly distributed across the first k nodes */
174:       /* Regular PETSc Distribution */
175:       x = M / m + ((M % m) > rank);
176:       if (rank >= (M % m)) xs = (rank * (PetscInt)(M / m) + M % m);
177:       else xs = rank * (PetscInt)(M / m) + rank;
178:     }
179:     PetscCallMPI(MPI_Allgather(&xs, 1, MPIU_INT, dd->lx, 1, MPIU_INT, comm));
180:     for (i = 0; i < m - 1; i++) dd->lx[i] = dd->lx[i + 1] - dd->lx[i];
181:     dd->lx[m - 1] = M - dd->lx[m - 1];
182:   } else {
183:     x  = lx[rank];
184:     xs = 0;
185:     for (i = 0; i < rank; i++) xs += lx[i];
186:     /* verify that data user provided is consistent */
187:     left = xs;
188:     for (i = rank; i < size; i++) left += lx[i];
189:     PetscCheck(left == M, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Sum of lx across processors not equal to M %" PetscInt_FMT " %" PetscInt_FMT, left, M);
190:   }

192:   /*
193:    check if the scatter requires more than one process neighbor or wraps around
194:    the domain more than once
195:   */
196:   PetscCheck((x >= s) || ((M <= 1) && (bx != DM_BOUNDARY_PERIODIC)), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local x-width of domain x %" PetscInt_FMT " is smaller than stencil width s %" PetscInt_FMT, x, s);

198:   xe = xs + x;

200:   /* determine ghost region (Xs) and region scattered into (IXs)  */
201:   if (xs - sDist > 0) {
202:     Xs  = xs - sDist;
203:     IXs = xs - sDist;
204:   } else {
205:     if (bx) Xs = xs - sDist;
206:     else Xs = 0;
207:     IXs = 0;
208:   }
209:   if (xe + sDist <= M) {
210:     Xe  = xe + sDist;
211:     IXe = xe + sDist;
212:   } else {
213:     if (bx) Xe = xe + sDist;
214:     else Xe = M;
215:     IXe = M;
216:   }

218:   if (bx == DM_BOUNDARY_PERIODIC || bx == DM_BOUNDARY_MIRROR) {
219:     Xs  = xs - sDist;
220:     Xe  = xe + sDist;
221:     IXs = xs - sDist;
222:     IXe = xe + sDist;
223:   }

225:   /* allocate the base parallel and sequential vectors */
226:   dd->Nlocal = dof * x;
227:   PetscCall(VecCreateMPIWithArray(comm, dof, dd->Nlocal, PETSC_DECIDE, NULL, &global));
228:   dd->nlocal = dof * (Xe - Xs);
229:   PetscCall(VecCreateSeqWithArray(PETSC_COMM_SELF, dof, dd->nlocal, NULL, &local));

231:   PetscCall(VecGetOwnershipRange(global, &start, NULL));

233:   /* Create Global to Local Vector Scatter Context */
234:   /* global to local must retrieve ghost points */
235:   PetscCall(ISCreateStride(comm, dof * (IXe - IXs), dof * (IXs - Xs), 1, &to));

237:   PetscCall(PetscMalloc1(x + 2 * sDist, &idx));

239:   for (i = 0; i < IXs - Xs; i++) idx[i] = -1; /* prepend with -1s if needed for ghosted case*/

241:   nn = IXs - Xs;
242:   if (bx == DM_BOUNDARY_PERIODIC) { /* Handle all cases with periodic first */
243:     for (i = 0; i < sDist; i++) {   /* Left ghost points */
244:       if ((xs - sDist + i) >= 0) idx[nn++] = xs - sDist + i;
245:       else idx[nn++] = M + (xs - sDist + i);
246:     }

248:     for (i = 0; i < x; i++) idx[nn++] = xs + i; /* Non-ghost points */

250:     for (i = 0; i < sDist; i++) { /* Right ghost points */
251:       if ((xe + i) < M) idx[nn++] = xe + i;
252:       else idx[nn++] = (xe + i) - M;
253:     }
254:   } else if (bx == DM_BOUNDARY_MIRROR) { /* Handle all cases with periodic first */
255:     for (i = 0; i < (sDist); i++) {      /* Left ghost points */
256:       if ((xs - sDist + i) >= 0) idx[nn++] = xs - sDist + i;
257:       else idx[nn++] = sDist - i;
258:     }

260:     for (i = 0; i < x; i++) idx[nn++] = xs + i; /* Non-ghost points */

262:     for (i = 0; i < (sDist); i++) { /* Right ghost points */
263:       if ((xe + i) < M) idx[nn++] = xe + i;
264:       else idx[nn++] = M - (i + 2);
265:     }
266:   } else { /* Now do all cases with no periodicity */
267:     if (0 <= xs - sDist) {
268:       for (i = 0; i < sDist; i++) idx[nn++] = xs - sDist + i;
269:     } else {
270:       for (i = 0; i < xs; i++) idx[nn++] = i;
271:     }

273:     for (i = 0; i < x; i++) idx[nn++] = xs + i;

275:     if ((xe + sDist) <= M) {
276:       for (i = 0; i < sDist; i++) idx[nn++] = xe + i;
277:     } else {
278:       for (i = xe; i < M; i++) idx[nn++] = i;
279:     }
280:   }

282:   PetscCall(ISCreateBlock(comm, dof, nn - IXs + Xs, &idx[IXs - Xs], PETSC_USE_POINTER, &from));
283:   PetscCall(VecScatterCreate(global, from, local, to, &gtol));
284:   PetscCall(ISDestroy(&to));
285:   PetscCall(ISDestroy(&from));
286:   PetscCall(VecDestroy(&local));
287:   PetscCall(VecDestroy(&global));

289:   dd->xs = dof * xs;
290:   dd->xe = dof * xe;
291:   dd->ys = 0;
292:   dd->ye = 1;
293:   dd->zs = 0;
294:   dd->ze = 1;
295:   dd->Xs = dof * Xs;
296:   dd->Xe = dof * Xe;
297:   dd->Ys = 0;
298:   dd->Ye = 1;
299:   dd->Zs = 0;
300:   dd->Ze = 1;

302:   dd->gtol      = gtol;
303:   dd->base      = dof * xs;
304:   da->ops->view = DMView_DA_1d;

306:   /*
307:      Set the local to global ordering in the global vector, this allows use
308:      of VecSetValuesLocal().
309:   */
310:   for (i = 0; i < Xe - IXe; i++) idx[nn++] = -1; /* pad with -1s if needed for ghosted case*/

312:   PetscCall(ISLocalToGlobalMappingCreate(comm, dof, nn, idx, PETSC_OWN_POINTER, &da->ltogmap));

314:   PetscFunctionReturn(PETSC_SUCCESS);
315: }

317: /*@C
318:    DMDACreate1d - Creates an object that will manage the communication of  one-dimensional
319:    regular array data that is distributed across some processors.

321:    Collective

323:    Input Parameters:
324: +  comm - MPI communicator
325: .  bx - type of ghost cells at the boundary the array should have, if any. Use
326:           `DM_BOUNDARY_NONE`, `DM_BOUNDARY_GHOSTED`, or `DM_BOUNDARY_PERIODIC`.
327: .  M - global dimension of the array (that is the number of grid points)
328:             from the command line with -da_grid_x <M>)
329: .  dof - number of degrees of freedom per node
330: .  s - stencil width
331: -  lx - array containing number of nodes in the X direction on each processor,
332:         or NULL. If non-null, must be of length as the number of processes in the MPI_Comm.
333:         The sum of these entries must equal M

335:    Output Parameter:
336: .  da - the resulting distributed array object

338:    Options Database Keys:
339: +  -dm_view - Calls `DMView()` at the conclusion of `DMDACreate1d()`
340: .  -da_grid_x <nx> - number of grid points in x direction
341: .  -da_refine_x <rx> - refinement factor
342: -  -da_refine <n> - refine the `DMDA` n times before creating it

344:    Level: beginner

346:    Notes:
347:    The array data itself is NOT stored in the `DMDA`, it is stored in `Vec` objects;
348:    The appropriate vector objects can be obtained with calls to `DMCreateGlobalVector()`
349:    and `DMCreateLocalVector()` and calls to `VecDuplicate()` if more are needed.

351:    You must call `DMSetUp()` after this call before using this `DM`.

353:    If you wish to use the options database to change values in the `DMDA` call `DMSetFromOptions()` after this call
354:    but before `DMSetUp()`.

356: .seealso: `DMDA`, `DM`, `DMDestroy()`, `DMView()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMGlobalToLocalBegin()`, `DMDASetRefinementFactor()`,
357:           `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`, `DMLocalToLocalBegin()`, `DMLocalToLocalEnd()`, `DMDAGetRefinementFactor()`,
358:           `DMDAGetInfo()`, `DMCreateGlobalVector()`, `DMCreateLocalVector()`, `DMDACreateNaturalVector()`, `DMLoad()`, `DMDAGetOwnershipRanges()`,
359:           `DMStagCreate1d()`
360: @*/
361: PetscErrorCode DMDACreate1d(MPI_Comm comm, DMBoundaryType bx, PetscInt M, PetscInt dof, PetscInt s, const PetscInt lx[], DM *da)
362: {
363:   PetscMPIInt size;

365:   PetscFunctionBegin;
366:   PetscCall(DMDACreate(comm, da));
367:   PetscCall(DMSetDimension(*da, 1));
368:   PetscCall(DMDASetSizes(*da, M, 1, 1));
369:   PetscCallMPI(MPI_Comm_size(comm, &size));
370:   PetscCall(DMDASetNumProcs(*da, size, PETSC_DECIDE, PETSC_DECIDE));
371:   PetscCall(DMDASetBoundaryType(*da, bx, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE));
372:   PetscCall(DMDASetDof(*da, dof));
373:   PetscCall(DMDASetStencilWidth(*da, s));
374:   PetscCall(DMDASetOwnershipRanges(*da, lx, NULL, NULL));
375:   PetscFunctionReturn(PETSC_SUCCESS);
376: }