Actual source code: da2.c

petsc-master 2020-07-10
Report Typos and Errors

  2:  #include <petsc/private/dmdaimpl.h>
  3:  #include <petscdraw.h>

  5: static PetscErrorCode DMView_DA_2d(DM da,PetscViewer viewer)
  6: {
  8:   PetscMPIInt    rank;
  9:   PetscBool      iascii,isdraw,isglvis,isbinary;
 10:   DM_DA          *dd = (DM_DA*)da->data;
 11: #if defined(PETSC_HAVE_MATLAB_ENGINE)
 12:   PetscBool ismatlab;
 13: #endif

 16:   MPI_Comm_rank(PetscObjectComm((PetscObject)da),&rank);

 18:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
 19:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
 20:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERGLVIS,&isglvis);
 21:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
 22: #if defined(PETSC_HAVE_MATLAB_ENGINE)
 23:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERMATLAB,&ismatlab);
 24: #endif
 25:   if (iascii) {
 26:     PetscViewerFormat format;

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

 71:     PetscViewerDrawGetDraw(viewer,0,&draw);
 72:     PetscDrawIsNull(draw,&isnull);
 73:     if (isnull) return(0);

 75:     PetscDrawCheckResizedWindow(draw);
 76:     PetscDrawClear(draw);
 77:     PetscDrawSetCoordinates(draw,xmin,ymin,xmax,ymax);

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

 95:     PetscDrawCollectiveBegin(draw);
 96:     /* draw my box */
 97:     xmin = dd->xs/dd->w; xmax =(dd->xe-1)/dd->w; ymin = dd->ys; ymax = dd->ye - 1;
 98:     PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_RED);
 99:     PetscDrawLine(draw,xmin,ymin,xmin,ymax,PETSC_DRAW_RED);
100:     PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_RED);
101:     PetscDrawLine(draw,xmax,ymin,xmax,ymax,PETSC_DRAW_RED);
102:     /* put in numbers */
103:     base = (dd->base)/dd->w;
104:     for (y=ymin; y<=ymax; y++) {
105:       for (x=xmin; x<=xmax; x++) {
106:         PetscSNPrintf(node,sizeof(node),"%d",(int)base++);
107:         PetscDrawString(draw,x,y,PETSC_DRAW_BLACK,node);
108:       }
109:     }
110:     PetscDrawCollectiveEnd(draw);
111:     PetscDrawFlush(draw);
112:     PetscDrawPause(draw);

114:     PetscDrawCollectiveBegin(draw);
115:     /* overlay ghost numbers, useful for error checking */
116:     ISLocalToGlobalMappingGetBlockIndices(da->ltogmap,&idx);
117:     base = 0; xmin = dd->Xs; xmax = dd->Xe; ymin = dd->Ys; ymax = dd->Ye;
118:     for (y=ymin; y<ymax; y++) {
119:       for (x=xmin; x<xmax; x++) {
120:         if ((base % dd->w) == 0) {
121:           PetscSNPrintf(node,sizeof(node),"%d",(int)(idx[base/dd->w]));
122:           PetscDrawString(draw,x/dd->w,y,PETSC_DRAW_BLUE,node);
123:         }
124:         base++;
125:       }
126:     }
127:     ISLocalToGlobalMappingRestoreBlockIndices(da->ltogmap,&idx);
128:     PetscDrawCollectiveEnd(draw);
129:     PetscDrawFlush(draw);
130:     PetscDrawPause(draw);
131:     PetscDrawSave(draw);
132:   } else if (isglvis) {
133:     DMView_DA_GLVis(da,viewer);
134:   } else if (isbinary) {
135:     DMView_DA_Binary(da,viewer);
136: #if defined(PETSC_HAVE_MATLAB_ENGINE)
137:   } else if (ismatlab) {
138:     DMView_DA_Matlab(da,viewer);
139: #endif
140:   }
141:   return(0);
142: }


145: #if defined(new)
146: /*
147:   DMDAGetDiagonal_MFFD - Gets the diagonal for a matrix free matrix where local
148:     function lives on a DMDA

150:         y ~= (F(u + ha) - F(u))/h,
151:   where F = nonlinear function, as set by SNESSetFunction()
152:         u = current iterate
153:         h = difference interval
154: */
155: PetscErrorCode DMDAGetDiagonal_MFFD(DM da,Vec U,Vec a)
156: {
157:   PetscScalar    h,*aa,*ww,v;
158:   PetscReal      epsilon = PETSC_SQRT_MACHINE_EPSILON,umin = 100.0*PETSC_SQRT_MACHINE_EPSILON;
160:   PetscInt       gI,nI;
161:   MatStencil     stencil;
162:   DMDALocalInfo  info;

165:   (*ctx->func)(0,U,a,ctx->funcctx);
166:   (*ctx->funcisetbase)(U,ctx->funcctx);

168:   VecGetArray(U,&ww);
169:   VecGetArray(a,&aa);

171:   nI = 0;
172:   h  = ww[gI];
173:   if (h == 0.0) h = 1.0;
174:   if (PetscAbsScalar(h) < umin && PetscRealPart(h) >= 0.0) h = umin;
175:   else if (PetscRealPart(h) < 0.0 && PetscAbsScalar(h) < umin) h = -umin;
176:   h *= epsilon;

178:   ww[gI] += h;
179:   (*ctx->funci)(i,w,&v,ctx->funcctx);
180:   aa[nI]  = (v - aa[nI])/h;
181:   ww[gI] -= h;
182:   nI++;

184:   VecRestoreArray(U,&ww);
185:   VecRestoreArray(a,&aa);
186:   return(0);
187: }
188: #endif

190: PetscErrorCode  DMSetUp_DA_2D(DM da)
191: {
192:   DM_DA            *dd = (DM_DA*)da->data;
193:   const PetscInt   M            = dd->M;
194:   const PetscInt   N            = dd->N;
195:   PetscInt         m            = dd->m;
196:   PetscInt         n            = dd->n;
197:   const PetscInt   dof          = dd->w;
198:   const PetscInt   s            = dd->s;
199:   DMBoundaryType   bx           = dd->bx;
200:   DMBoundaryType   by           = dd->by;
201:   DMDAStencilType  stencil_type = dd->stencil_type;
202:   PetscInt         *lx          = dd->lx;
203:   PetscInt         *ly          = dd->ly;
204:   MPI_Comm         comm;
205:   PetscMPIInt      rank,size;
206:   PetscInt         xs,xe,ys,ye,x,y,Xs,Xe,Ys,Ye,IXs,IXe,IYs,IYe;
207:   PetscInt         up,down,left,right,i,n0,n1,n2,n3,n5,n6,n7,n8,*idx,nn;
208:   PetscInt         xbase,*bases,*ldims,j,x_t,y_t,s_t,base,count;
209:   PetscInt         s_x,s_y; /* s proportionalized to w */
210:   PetscInt         sn0 = 0,sn2 = 0,sn6 = 0,sn8 = 0;
211:   Vec              local,global;
212:   VecScatter       gtol;
213:   IS               to,from;
214:   PetscErrorCode   ierr;

217:   if (stencil_type == DMDA_STENCIL_BOX && (bx == DM_BOUNDARY_MIRROR || by == DM_BOUNDARY_MIRROR)) SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_SUP,"Mirror boundary and box stencil");
218:   PetscObjectGetComm((PetscObject)da,&comm);
219: #if !defined(PETSC_USE_64BIT_INDICES)
220:   if (((PetscInt64) M)*((PetscInt64) N)*((PetscInt64) dof) > (PetscInt64) PETSC_MPI_INT_MAX) SETERRQ3(comm,PETSC_ERR_INT_OVERFLOW,"Mesh of %D by %D by %D (dof) is too large for 32 bit indices",M,N,dof);
221: #endif

223:   MPI_Comm_size(comm,&size);
224:   MPI_Comm_rank(comm,&rank);

226:   dd->p = 1;
227:   if (m != PETSC_DECIDE) {
228:     if (m < 1) SETERRQ1(comm,PETSC_ERR_ARG_OUTOFRANGE,"Non-positive number of processors in X direction: %D",m);
229:     else if (m > size) SETERRQ2(comm,PETSC_ERR_ARG_OUTOFRANGE,"Too many processors in X direction: %D %d",m,size);
230:   }
231:   if (n != PETSC_DECIDE) {
232:     if (n < 1) SETERRQ1(comm,PETSC_ERR_ARG_OUTOFRANGE,"Non-positive number of processors in Y direction: %D",n);
233:     else if (n > size) SETERRQ2(comm,PETSC_ERR_ARG_OUTOFRANGE,"Too many processors in Y direction: %D %d",n,size);
234:   }

236:   if (m == PETSC_DECIDE || n == PETSC_DECIDE) {
237:     if (n != PETSC_DECIDE) {
238:       m = size/n;
239:     } else if (m != PETSC_DECIDE) {
240:       n = size/m;
241:     } else {
242:       /* try for squarish distribution */
243:       m = (PetscInt)(0.5 + PetscSqrtReal(((PetscReal)M)*((PetscReal)size)/((PetscReal)N)));
244:       if (!m) m = 1;
245:       while (m > 0) {
246:         n = size/m;
247:         if (m*n == size) break;
248:         m--;
249:       }
250:       if (M > N && m < n) {PetscInt _m = m; m = n; n = _m;}
251:     }
252:     if (m*n != size) SETERRQ(comm,PETSC_ERR_PLIB,"Unable to create partition, check the size of the communicator and input m and n ");
253:   } else if (m*n != size) SETERRQ(comm,PETSC_ERR_ARG_OUTOFRANGE,"Given Bad partition");

255:   if (M < m) SETERRQ2(comm,PETSC_ERR_ARG_OUTOFRANGE,"Partition in x direction is too fine! %D %D",M,m);
256:   if (N < n) SETERRQ2(comm,PETSC_ERR_ARG_OUTOFRANGE,"Partition in y direction is too fine! %D %D",N,n);

258:   /*
259:      Determine locally owned region
260:      xs is the first local node number, x is the number of local nodes
261:   */
262:   if (!lx) {
263:     PetscMalloc1(m, &dd->lx);
264:     lx   = dd->lx;
265:     for (i=0; i<m; i++) {
266:       lx[i] = M/m + ((M % m) > i);
267:     }
268:   }
269:   x  = lx[rank % m];
270:   xs = 0;
271:   for (i=0; i<(rank % m); i++) {
272:     xs += lx[i];
273:   }
274:   if (PetscDefined(USE_DEBUG)) {
275:     left = xs;
276:     for (i=(rank % m); i<m; i++) {
277:       left += lx[i];
278:     }
279:     if (left != M) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Sum of lx across processors not equal to M: %D %D",left,M);
280:   }

282:   /*
283:      Determine locally owned region
284:      ys is the first local node number, y is the number of local nodes
285:   */
286:   if (!ly) {
287:     PetscMalloc1(n, &dd->ly);
288:     ly   = dd->ly;
289:     for (i=0; i<n; i++) {
290:       ly[i] = N/n + ((N % n) > i);
291:     }
292:   }
293:   y  = ly[rank/m];
294:   ys = 0;
295:   for (i=0; i<(rank/m); i++) {
296:     ys += ly[i];
297:   }
298:   if (PetscDefined(USE_DEBUG)) {
299:     left = ys;
300:     for (i=(rank/m); i<n; i++) {
301:       left += ly[i];
302:     }
303:     if (left != N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Sum of ly across processors not equal to N: %D %D",left,N);
304:   }

306:   /*
307:    check if the scatter requires more than one process neighbor or wraps around
308:    the domain more than once
309:   */
310:   if ((x < s) && ((m > 1) || (bx == DM_BOUNDARY_PERIODIC))) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Local x-width of domain x %D is smaller than stencil width s %D",x,s);
311:   if ((y < s) && ((n > 1) || (by == DM_BOUNDARY_PERIODIC))) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Local y-width of domain y %D is smaller than stencil width s %D",y,s);
312:   xe = xs + x;
313:   ye = ys + y;

315:   /* determine ghost region (Xs) and region scattered into (IXs)  */
316:   if (xs-s > 0) {
317:     Xs = xs - s; IXs = xs - s;
318:   } else {
319:     if (bx) {
320:       Xs = xs - s;
321:     } else {
322:       Xs = 0;
323:     }
324:     IXs = 0;
325:   }
326:   if (xe+s <= M) {
327:     Xe = xe + s; IXe = xe + s;
328:   } else {
329:     if (bx) {
330:       Xs = xs - s; Xe = xe + s;
331:     } else {
332:       Xe = M;
333:     }
334:     IXe = M;
335:   }

337:   if (bx == DM_BOUNDARY_PERIODIC || bx == DM_BOUNDARY_MIRROR) {
338:     IXs = xs - s;
339:     IXe = xe + s;
340:     Xs  = xs - s;
341:     Xe  = xe + s;
342:   }

344:   if (ys-s > 0) {
345:     Ys = ys - s; IYs = ys - s;
346:   } else {
347:     if (by) {
348:       Ys = ys - s;
349:     } else {
350:       Ys = 0;
351:     }
352:     IYs = 0;
353:   }
354:   if (ye+s <= N) {
355:     Ye = ye + s; IYe = ye + s;
356:   } else {
357:     if (by) {
358:       Ye = ye + s;
359:     } else {
360:       Ye = N;
361:     }
362:     IYe = N;
363:   }

365:   if (by == DM_BOUNDARY_PERIODIC || by == DM_BOUNDARY_MIRROR) {
366:     IYs = ys - s;
367:     IYe = ye + s;
368:     Ys  = ys - s;
369:     Ye  = ye + s;
370:   }

372:   /* stencil length in each direction */
373:   s_x = s;
374:   s_y = s;

376:   /* determine starting point of each processor */
377:   nn       = x*y;
378:   PetscMalloc2(size+1,&bases,size,&ldims);
379:   MPI_Allgather(&nn,1,MPIU_INT,ldims,1,MPIU_INT,comm);
380:   bases[0] = 0;
381:   for (i=1; i<=size; i++) {
382:     bases[i] = ldims[i-1];
383:   }
384:   for (i=1; i<=size; i++) {
385:     bases[i] += bases[i-1];
386:   }
387:   base = bases[rank]*dof;

389:   /* allocate the base parallel and sequential vectors */
390:   dd->Nlocal = x*y*dof;
391:   VecCreateMPIWithArray(comm,dof,dd->Nlocal,PETSC_DECIDE,NULL,&global);
392:   dd->nlocal = (Xe-Xs)*(Ye-Ys)*dof;
393:   VecCreateSeqWithArray(PETSC_COMM_SELF,dof,dd->nlocal,NULL,&local);

395:   /* generate global to local vector scatter and local to global mapping*/

397:   /* global to local must include ghost points within the domain,
398:      but not ghost points outside the domain that aren't periodic */
399:   PetscMalloc1((IXe-IXs)*(IYe-IYs),&idx);
400:   if (stencil_type == DMDA_STENCIL_BOX) {
401:     left  = IXs - Xs; right = left + (IXe-IXs);
402:     down  = IYs - Ys; up = down + (IYe-IYs);
403:     count = 0;
404:     for (i=down; i<up; i++) {
405:       for (j=left; j<right; j++) {
406:         idx[count++] = j + i*(Xe-Xs);
407:       }
408:     }
409:     ISCreateBlock(comm,dof,count,idx,PETSC_OWN_POINTER,&to);

411:   } else {
412:     /* must drop into cross shape region */
413:     /*       ---------|
414:             |  top    |
415:          |---         ---| up
416:          |   middle      |
417:          |               |
418:          ----         ---- down
419:             | bottom  |
420:             -----------
421:          Xs xs        xe Xe */
422:     left  = xs - Xs; right = left + x;
423:     down  = ys - Ys; up = down + y;
424:     count = 0;
425:     /* bottom */
426:     for (i=(IYs-Ys); i<down; i++) {
427:       for (j=left; j<right; j++) {
428:         idx[count++] = j + i*(Xe-Xs);
429:       }
430:     }
431:     /* middle */
432:     for (i=down; i<up; i++) {
433:       for (j=(IXs-Xs); j<(IXe-Xs); j++) {
434:         idx[count++] = j + i*(Xe-Xs);
435:       }
436:     }
437:     /* top */
438:     for (i=up; i<up+IYe-ye; i++) {
439:       for (j=left; j<right; j++) {
440:         idx[count++] = j + i*(Xe-Xs);
441:       }
442:     }
443:     ISCreateBlock(comm,dof,count,idx,PETSC_OWN_POINTER,&to);
444:   }


447:   /* determine who lies on each side of us stored in    n6 n7 n8
448:                                                         n3    n5
449:                                                         n0 n1 n2
450:   */

452:   /* Assume the Non-Periodic Case */
453:   n1 = rank - m;
454:   if (rank % m) {
455:     n0 = n1 - 1;
456:   } else {
457:     n0 = -1;
458:   }
459:   if ((rank+1) % m) {
460:     n2 = n1 + 1;
461:     n5 = rank + 1;
462:     n8 = rank + m + 1; if (n8 >= m*n) n8 = -1;
463:   } else {
464:     n2 = -1; n5 = -1; n8 = -1;
465:   }
466:   if (rank % m) {
467:     n3 = rank - 1;
468:     n6 = n3 + m; if (n6 >= m*n) n6 = -1;
469:   } else {
470:     n3 = -1; n6 = -1;
471:   }
472:   n7 = rank + m; if (n7 >= m*n) n7 = -1;

474:   if (bx == DM_BOUNDARY_PERIODIC && by == DM_BOUNDARY_PERIODIC) {
475:     /* Modify for Periodic Cases */
476:     /* Handle all four corners */
477:     if ((n6 < 0) && (n7 < 0) && (n3 < 0)) n6 = m-1;
478:     if ((n8 < 0) && (n7 < 0) && (n5 < 0)) n8 = 0;
479:     if ((n2 < 0) && (n5 < 0) && (n1 < 0)) n2 = size-m;
480:     if ((n0 < 0) && (n3 < 0) && (n1 < 0)) n0 = size-1;

482:     /* Handle Top and Bottom Sides */
483:     if (n1 < 0) n1 = rank + m * (n-1);
484:     if (n7 < 0) n7 = rank - m * (n-1);
485:     if ((n3 >= 0) && (n0 < 0)) n0 = size - m + rank - 1;
486:     if ((n3 >= 0) && (n6 < 0)) n6 = (rank%m)-1;
487:     if ((n5 >= 0) && (n2 < 0)) n2 = size - m + rank + 1;
488:     if ((n5 >= 0) && (n8 < 0)) n8 = (rank%m)+1;

490:     /* Handle Left and Right Sides */
491:     if (n3 < 0) n3 = rank + (m-1);
492:     if (n5 < 0) n5 = rank - (m-1);
493:     if ((n1 >= 0) && (n0 < 0)) n0 = rank-1;
494:     if ((n1 >= 0) && (n2 < 0)) n2 = rank-2*m+1;
495:     if ((n7 >= 0) && (n6 < 0)) n6 = rank+2*m-1;
496:     if ((n7 >= 0) && (n8 < 0)) n8 = rank+1;
497:   } else if (by == DM_BOUNDARY_PERIODIC) {  /* Handle Top and Bottom Sides */
498:     if (n1 < 0) n1 = rank + m * (n-1);
499:     if (n7 < 0) n7 = rank - m * (n-1);
500:     if ((n3 >= 0) && (n0 < 0)) n0 = size - m + rank - 1;
501:     if ((n3 >= 0) && (n6 < 0)) n6 = (rank%m)-1;
502:     if ((n5 >= 0) && (n2 < 0)) n2 = size - m + rank + 1;
503:     if ((n5 >= 0) && (n8 < 0)) n8 = (rank%m)+1;
504:   } else if (bx == DM_BOUNDARY_PERIODIC) { /* Handle Left and Right Sides */
505:     if (n3 < 0) n3 = rank + (m-1);
506:     if (n5 < 0) n5 = rank - (m-1);
507:     if ((n1 >= 0) && (n0 < 0)) n0 = rank-1;
508:     if ((n1 >= 0) && (n2 < 0)) n2 = rank-2*m+1;
509:     if ((n7 >= 0) && (n6 < 0)) n6 = rank+2*m-1;
510:     if ((n7 >= 0) && (n8 < 0)) n8 = rank+1;
511:   }

513:   PetscMalloc1(9,&dd->neighbors);

515:   dd->neighbors[0] = n0;
516:   dd->neighbors[1] = n1;
517:   dd->neighbors[2] = n2;
518:   dd->neighbors[3] = n3;
519:   dd->neighbors[4] = rank;
520:   dd->neighbors[5] = n5;
521:   dd->neighbors[6] = n6;
522:   dd->neighbors[7] = n7;
523:   dd->neighbors[8] = n8;

525:   if (stencil_type == DMDA_STENCIL_STAR) {
526:     /* save corner processor numbers */
527:     sn0 = n0; sn2 = n2; sn6 = n6; sn8 = n8;
528:     n0  = n2 = n6 = n8 = -1;
529:   }

531:   PetscMalloc1((Xe-Xs)*(Ye-Ys),&idx);

533:   nn = 0;
534:   xbase = bases[rank];
535:   for (i=1; i<=s_y; i++) {
536:     if (n0 >= 0) { /* left below */
537:       x_t = lx[n0 % m];
538:       y_t = ly[(n0/m)];
539:       s_t = bases[n0] + x_t*y_t - (s_y-i)*x_t - s_x;
540:       for (j=0; j<s_x; j++) idx[nn++] = s_t++;
541:     }

543:     if (n1 >= 0) { /* directly below */
544:       x_t = x;
545:       y_t = ly[(n1/m)];
546:       s_t = bases[n1] + x_t*y_t - (s_y+1-i)*x_t;
547:       for (j=0; j<x_t; j++) idx[nn++] = s_t++;
548:     } else if (by == DM_BOUNDARY_MIRROR) {
549:       for (j=0; j<x; j++) idx[nn++] = bases[rank] + x*(s_y - i + 1)  + j;
550:     }

552:     if (n2 >= 0) { /* right below */
553:       x_t = lx[n2 % m];
554:       y_t = ly[(n2/m)];
555:       s_t = bases[n2] + x_t*y_t - (s_y+1-i)*x_t;
556:       for (j=0; j<s_x; j++) idx[nn++] = s_t++;
557:     }
558:   }

560:   for (i=0; i<y; i++) {
561:     if (n3 >= 0) { /* directly left */
562:       x_t = lx[n3 % m];
563:       /* y_t = y; */
564:       s_t = bases[n3] + (i+1)*x_t - s_x;
565:       for (j=0; j<s_x; j++) idx[nn++] = s_t++;
566:     } else if (bx == DM_BOUNDARY_MIRROR) {
567:       for (j=0; j<s_x; j++) idx[nn++] = bases[rank] + x*i + s_x - j;
568:     }

570:     for (j=0; j<x; j++) idx[nn++] = xbase++; /* interior */

572:     if (n5 >= 0) { /* directly right */
573:       x_t = lx[n5 % m];
574:       /* y_t = y; */
575:       s_t = bases[n5] + (i)*x_t;
576:       for (j=0; j<s_x; j++) idx[nn++] = s_t++;
577:     } else if (bx == DM_BOUNDARY_MIRROR) {
578:       for (j=0; j<s_x; j++) idx[nn++] = bases[rank] + x*(i + 1) - 2 - j;
579:     }
580:   }

582:   for (i=1; i<=s_y; i++) {
583:     if (n6 >= 0) { /* left above */
584:       x_t = lx[n6 % m];
585:       /* y_t = ly[(n6/m)]; */
586:       s_t = bases[n6] + (i)*x_t - s_x;
587:       for (j=0; j<s_x; j++) idx[nn++] = s_t++;
588:     }

590:     if (n7 >= 0) { /* directly above */
591:       x_t = x;
592:       /* y_t = ly[(n7/m)]; */
593:       s_t = bases[n7] + (i-1)*x_t;
594:       for (j=0; j<x_t; j++) idx[nn++] = s_t++;
595:     } else if (by == DM_BOUNDARY_MIRROR) {
596:       for (j=0; j<x; j++) idx[nn++] = bases[rank] + x*(y - i - 1)  + j;
597:     }

599:     if (n8 >= 0) { /* right above */
600:       x_t = lx[n8 % m];
601:       /* y_t = ly[(n8/m)]; */
602:       s_t = bases[n8] + (i-1)*x_t;
603:       for (j=0; j<s_x; j++) idx[nn++] = s_t++;
604:     }
605:   }

607:   ISCreateBlock(comm,dof,nn,idx,PETSC_USE_POINTER,&from);
608:   VecScatterCreate(global,from,local,to,&gtol);
609:   PetscLogObjectParent((PetscObject)da,(PetscObject)gtol);
610:   ISDestroy(&to);
611:   ISDestroy(&from);

613:   if (stencil_type == DMDA_STENCIL_STAR) {
614:     n0 = sn0; n2 = sn2; n6 = sn6; n8 = sn8;
615:   }

617:   if (((stencil_type == DMDA_STENCIL_STAR)  || (bx && bx != DM_BOUNDARY_PERIODIC) || (by && by != DM_BOUNDARY_PERIODIC))) {
618:     /*
619:         Recompute the local to global mappings, this time keeping the
620:       information about the cross corner processor numbers and any ghosted
621:       but not periodic indices.
622:     */
623:     nn    = 0;
624:     xbase = bases[rank];
625:     for (i=1; i<=s_y; i++) {
626:       if (n0 >= 0) { /* left below */
627:         x_t = lx[n0 % m];
628:         y_t = ly[(n0/m)];
629:         s_t = bases[n0] + x_t*y_t - (s_y-i)*x_t - s_x;
630:         for (j=0; j<s_x; j++) idx[nn++] = s_t++;
631:       } else if (xs-Xs > 0 && ys-Ys > 0) {
632:         for (j=0; j<s_x; j++) idx[nn++] = -1;
633:       }
634:       if (n1 >= 0) { /* directly below */
635:         x_t = x;
636:         y_t = ly[(n1/m)];
637:         s_t = bases[n1] + x_t*y_t - (s_y+1-i)*x_t;
638:         for (j=0; j<x_t; j++) idx[nn++] = s_t++;
639:       } else if (ys-Ys > 0) {
640:         if (by == DM_BOUNDARY_MIRROR) {
641:           for (j=0; j<x; j++) idx[nn++] = bases[rank] + x*(s_y - i + 1)  + j;
642:         } else {
643:           for (j=0; j<x; j++) idx[nn++] = -1;
644:         }
645:       }
646:       if (n2 >= 0) { /* right below */
647:         x_t = lx[n2 % m];
648:         y_t = ly[(n2/m)];
649:         s_t = bases[n2] + x_t*y_t - (s_y+1-i)*x_t;
650:         for (j=0; j<s_x; j++) idx[nn++] = s_t++;
651:       } else if (Xe-xe> 0 && ys-Ys > 0) {
652:         for (j=0; j<s_x; j++) idx[nn++] = -1;
653:       }
654:     }

656:     for (i=0; i<y; i++) {
657:       if (n3 >= 0) { /* directly left */
658:         x_t = lx[n3 % m];
659:         /* y_t = y; */
660:         s_t = bases[n3] + (i+1)*x_t - s_x;
661:         for (j=0; j<s_x; j++) idx[nn++] = s_t++;
662:       } else if (xs-Xs > 0) {
663:         if (bx == DM_BOUNDARY_MIRROR) {
664:           for (j=0; j<s_x; j++) idx[nn++] = bases[rank] + x*i + s_x - j;
665:         } else {
666:           for (j=0; j<s_x; j++) idx[nn++] = -1;
667:         }
668:       }

670:       for (j=0; j<x; j++) idx[nn++] = xbase++; /* interior */

672:       if (n5 >= 0) { /* directly right */
673:         x_t = lx[n5 % m];
674:         /* y_t = y; */
675:         s_t = bases[n5] + (i)*x_t;
676:         for (j=0; j<s_x; j++) idx[nn++] = s_t++;
677:       } else if (Xe-xe > 0) {
678:         if (bx == DM_BOUNDARY_MIRROR) {
679:           for (j=0; j<s_x; j++) idx[nn++] = bases[rank] + x*(i + 1) - 2 - j;
680:         } else {
681:           for (j=0; j<s_x; j++) idx[nn++] = -1;
682:         }
683:       }
684:     }

686:     for (i=1; i<=s_y; i++) {
687:       if (n6 >= 0) { /* left above */
688:         x_t = lx[n6 % m];
689:         /* y_t = ly[(n6/m)]; */
690:         s_t = bases[n6] + (i)*x_t - s_x;
691:         for (j=0; j<s_x; j++) idx[nn++] = s_t++;
692:       } else if (xs-Xs > 0 && Ye-ye > 0) {
693:         for (j=0; j<s_x; j++) idx[nn++] = -1;
694:       }
695:       if (n7 >= 0) { /* directly above */
696:         x_t = x;
697:         /* y_t = ly[(n7/m)]; */
698:         s_t = bases[n7] + (i-1)*x_t;
699:         for (j=0; j<x_t; j++) idx[nn++] = s_t++;
700:       } else if (Ye-ye > 0) {
701:         if (by == DM_BOUNDARY_MIRROR) {
702:           for (j=0; j<x; j++) idx[nn++] = bases[rank] + x*(y - i - 1)  + j;
703:         } else {
704:           for (j=0; j<x; j++) idx[nn++] = -1;
705:         }
706:       }
707:       if (n8 >= 0) { /* right above */
708:         x_t = lx[n8 % m];
709:         /* y_t = ly[(n8/m)]; */
710:         s_t = bases[n8] + (i-1)*x_t;
711:         for (j=0; j<s_x; j++) idx[nn++] = s_t++;
712:       } else if (Xe-xe > 0 && Ye-ye > 0) {
713:         for (j=0; j<s_x; j++) idx[nn++] = -1;
714:       }
715:     }
716:   }
717:   /*
718:      Set the local to global ordering in the global vector, this allows use
719:      of VecSetValuesLocal().
720:   */
721:   ISLocalToGlobalMappingCreate(comm,dof,nn,idx,PETSC_OWN_POINTER,&da->ltogmap);
722:   PetscLogObjectParent((PetscObject)da,(PetscObject)da->ltogmap);

724:   PetscFree2(bases,ldims);
725:   dd->m = m;  dd->n  = n;
726:   /* note petsc expects xs/xe/Xs/Xe to be multiplied by #dofs in many places */
727:   dd->xs = xs*dof; dd->xe = xe*dof; dd->ys = ys; dd->ye = ye; dd->zs = 0; dd->ze = 1;
728:   dd->Xs = Xs*dof; dd->Xe = Xe*dof; dd->Ys = Ys; dd->Ye = Ye; dd->Zs = 0; dd->Ze = 1;

730:   VecDestroy(&local);
731:   VecDestroy(&global);

733:   dd->gtol      = gtol;
734:   dd->base      = base;
735:   da->ops->view = DMView_DA_2d;
736:   dd->ltol      = NULL;
737:   dd->ao        = NULL;
738:   return(0);
739: }

741: /*@C
742:    DMDACreate2d -  Creates an object that will manage the communication of  two-dimensional
743:    regular array data that is distributed across some processors.

745:    Collective

747:    Input Parameters:
748: +  comm - MPI communicator
749: .  bx,by - type of ghost nodes the array have.
750:          Use one of DM_BOUNDARY_NONE, DM_BOUNDARY_GHOSTED, DM_BOUNDARY_PERIODIC.
751: .  stencil_type - stencil type.  Use either DMDA_STENCIL_BOX or DMDA_STENCIL_STAR.
752: .  M,N - global dimension in each direction of the array
753: .  m,n - corresponding number of processors in each dimension
754:          (or PETSC_DECIDE to have calculated)
755: .  dof - number of degrees of freedom per node
756: .  s - stencil width
757: -  lx, ly - arrays containing the number of nodes in each cell along
758:            the x and y coordinates, or NULL. If non-null, these
759:            must be of length as m and n, and the corresponding
760:            m and n cannot be PETSC_DECIDE. The sum of the lx[] entries
761:            must be M, and the sum of the ly[] entries must be N.

763:    Output Parameter:
764: .  da - the resulting distributed array object

766:    Options Database Key:
767: +  -dm_view - Calls DMView() at the conclusion of DMDACreate2d()
768: .  -da_grid_x <nx> - number of grid points in x direction
769: .  -da_grid_y <ny> - number of grid points in y direction
770: .  -da_processors_x <nx> - number of processors in x direction
771: .  -da_processors_y <ny> - number of processors in y direction
772: .  -da_refine_x <rx> - refinement ratio in x direction
773: .  -da_refine_y <ry> - refinement ratio in y direction
774: -  -da_refine <n> - refine the DMDA n times before creating


777:    Level: beginner

779:    Notes:
780:    The stencil type DMDA_STENCIL_STAR with width 1 corresponds to the
781:    standard 5-pt stencil, while DMDA_STENCIL_BOX with width 1 denotes
782:    the standard 9-pt stencil.

784:    The array data itself is NOT stored in the DMDA, it is stored in Vec objects;
785:    The appropriate vector objects can be obtained with calls to DMCreateGlobalVector()
786:    and DMCreateLocalVector() and calls to VecDuplicate() if more are needed.

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

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

793: .seealso: DMDestroy(), DMView(), DMDACreate1d(), DMDACreate3d(), DMGlobalToLocalBegin(), DMDAGetRefinementFactor(),
794:           DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMLocalToLocalBegin(), DMLocalToLocalEnd(), DMDASetRefinementFactor(),
795:           DMDAGetInfo(), DMCreateGlobalVector(), DMCreateLocalVector(), DMDACreateNaturalVector(), DMLoad(), DMDAGetOwnershipRanges(),
796:           DMStagCreate2d()

798: @*/

800: PetscErrorCode  DMDACreate2d(MPI_Comm comm,DMBoundaryType bx,DMBoundaryType by,DMDAStencilType stencil_type,
801:                              PetscInt M,PetscInt N,PetscInt m,PetscInt n,PetscInt dof,PetscInt s,const PetscInt lx[],const PetscInt ly[],DM *da)
802: {

806:   DMDACreate(comm, da);
807:   DMSetDimension(*da, 2);
808:   DMDASetSizes(*da, M, N, 1);
809:   DMDASetNumProcs(*da, m, n, PETSC_DECIDE);
810:   DMDASetBoundaryType(*da, bx, by, DM_BOUNDARY_NONE);
811:   DMDASetDof(*da, dof);
812:   DMDASetStencilType(*da, stencil_type);
813:   DMDASetStencilWidth(*da, s);
814:   DMDASetOwnershipRanges(*da, lx, ly, NULL);
815:   return(0);
816: }