Actual source code: da1.c

petsc-master 2016-06-26
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  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>     /*I  "petscdmda.h"   I*/

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

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

 25:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
 26:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
 27:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
 28: #if defined(PETSC_HAVE_MATLAB_ENGINE)
 29:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERMATLAB,&ismatlab);
 30: #endif
 31:   if (iascii) {
 32:     PetscViewerFormat format;

 34:     PetscViewerGetFormat(viewer, &format);
 35:     if (format != PETSC_VIEWER_ASCII_VTK && format != PETSC_VIEWER_ASCII_VTK_CELL) {
 36:       DMDALocalInfo info;
 37:       DMDAGetLocalInfo(da,&info);
 38:       PetscViewerASCIIPushSynchronized(viewer);
 39:       PetscViewerASCIISynchronizedPrintf(viewer,"Processor [%d] M %D m %D w %D s %D\n",rank,dd->M,dd->m,dd->w,dd->s);
 40:       PetscViewerASCIISynchronizedPrintf(viewer,"X range of indices: %D %D\n",info.xs,info.xs+info.xm);
 41:       PetscViewerFlush(viewer);
 42:       PetscViewerASCIIPopSynchronized(viewer);
 43:     } else {
 44:       DMView_DA_VTK(da, viewer);
 45:     }
 46:   } else if (isdraw) {
 47:     PetscDraw draw;
 48:     double    ymin = -1,ymax = 1,xmin = -1,xmax = dd->M,x;
 49:     PetscInt  base;
 50:     char      node[10];
 51:     PetscBool isnull;

 53:     PetscViewerDrawGetDraw(viewer,0,&draw);
 54:     PetscDrawIsNull(draw,&isnull);
 55:     if (isnull) return(0);

 57:     PetscDrawCheckResizedWindow(draw);
 58:     PetscDrawClear(draw);
 59:     PetscDrawSetCoordinates(draw,xmin,ymin,xmax,ymax);

 61:     PetscDrawCollectiveBegin(draw);
 62:     /* first processor draws all node lines */
 63:     if (!rank) {
 64:       PetscInt xmin_tmp;
 65:       ymin = 0.0; ymax = 0.3;
 66:       for (xmin_tmp=0; xmin_tmp < dd->M; xmin_tmp++) {
 67:         PetscDrawLine(draw,(double)xmin_tmp,ymin,(double)xmin_tmp,ymax,PETSC_DRAW_BLACK);
 68:       }
 69:       xmin = 0.0; xmax = dd->M - 1;
 70:       PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_BLACK);
 71:       PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_BLACK);
 72:     }
 73:     PetscDrawCollectiveEnd(draw);
 74:     PetscDrawFlush(draw);
 75:     PetscDrawPause(draw);

 77:     PetscDrawCollectiveBegin(draw);
 78:     /* draw my box */
 79:     ymin = 0; ymax = 0.3; xmin = dd->xs / dd->w; xmax = (dd->xe / dd->w)  - 1;
 80:     PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_RED);
 81:     PetscDrawLine(draw,xmin,ymin,xmin,ymax,PETSC_DRAW_RED);
 82:     PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_RED);
 83:     PetscDrawLine(draw,xmax,ymin,xmax,ymax,PETSC_DRAW_RED);
 84:     /* Put in index numbers */
 85:     base = dd->base / dd->w;
 86:     for (x=xmin; x<=xmax; x++) {
 87:       PetscSNPrintf(node,sizeof(node),"%d",(int)base++);
 88:       PetscDrawString(draw,x,ymin,PETSC_DRAW_RED,node);
 89:     }
 90:     PetscDrawCollectiveEnd(draw);
 91:     PetscDrawFlush(draw);
 92:     PetscDrawPause(draw);
 93:     PetscDrawSave(draw);
 94:   } else if (isbinary) {
 95:     DMView_DA_Binary(da,viewer);
 96: #if defined(PETSC_HAVE_MATLAB_ENGINE)
 97:   } else if (ismatlab) {
 98:     DMView_DA_Matlab(da,viewer);
 99: #endif
100:   }
101:   return(0);
102: }


107: PetscErrorCode  DMSetUp_DA_1D(DM da)
108: {
109:   DM_DA            *dd   = (DM_DA*)da->data;
110:   const PetscInt   M     = dd->M;
111:   const PetscInt   dof   = dd->w;
112:   const PetscInt   s     = dd->s;
113:   const PetscInt   sDist = s;  /* stencil distance in points */
114:   const PetscInt   *lx   = dd->lx;
115:   DMBoundaryType   bx    = dd->bx;
116:   MPI_Comm         comm;
117:   Vec              local, global;
118:   VecScatter       gtol;
119:   IS               to, from;
120:   PetscBool        flg1 = PETSC_FALSE, flg2 = PETSC_FALSE;
121:   PetscMPIInt      rank, size;
122:   PetscInt         i,*idx,nn,left,xs,xe,x,Xs,Xe,start,m,IXs,IXe;
123:   PetscErrorCode   ierr;

126:   PetscObjectGetComm((PetscObject) da, &comm);
127:   MPI_Comm_size(comm,&size);
128:   MPI_Comm_rank(comm,&rank);

130:   dd->p = 1;
131:   dd->n = 1;
132:   dd->m = size;
133:   m     = dd->m;

135:   if (s > 0) {
136:     /* if not communicating data then should be ok to have nothing on some processes */
137:     if (M < m) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"More processes than data points! %D %D",m,M);
138:     if ((M-1) < s && size > 1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Array is too small for stencil! %D %D",M-1,s);
139:   }

141:   /*
142:      Determine locally owned region
143:      xs is the first local node number, x is the number of local nodes
144:   */
145:   if (!lx) {
146:     PetscMalloc1(m, &dd->lx);
147:     PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_blockcomm",&flg1,NULL);
148:     PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_nodes_at_end",&flg2,NULL);
149:     if (flg1) {      /* Block Comm type Distribution */
150:       xs = rank*M/m;
151:       x  = (rank + 1)*M/m - xs;
152:     } else if (flg2) { /* The odd nodes are evenly distributed across last nodes */
153:       x = (M + rank)/m;
154:       if (M/m == x) xs = rank*x;
155:       else          xs = rank*(x-1) + (M+rank)%(x*m);
156:     } else { /* The odd nodes are evenly distributed across the first k nodes */
157:       /* Regular PETSc Distribution */
158:       x = M/m + ((M % m) > rank);
159:       if (rank >= (M % m)) xs = (rank * (PetscInt)(M/m) + M % m);
160:       else                 xs = rank * (PetscInt)(M/m) + rank;
161:     }
162:     MPI_Allgather(&xs,1,MPIU_INT,dd->lx,1,MPIU_INT,comm);
163:     for (i=0; i<m-1; i++) dd->lx[i] = dd->lx[i+1] - dd->lx[i];
164:     dd->lx[m-1] = M - dd->lx[m-1];
165:   } else {
166:     x  = lx[rank];
167:     xs = 0;
168:     for (i=0; i<rank; i++) xs += lx[i];
169:     /* verify that data user provided is consistent */
170:     left = xs;
171:     for (i=rank; i<size; i++) left += lx[i];
172:     if (left != M) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Sum of lx across processors not equal to M %D %D",left,M);
173:   }

175:   /*
176:    check if the scatter requires more than one process neighbor or wraps around
177:    the domain more than once
178:   */
179:   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);

181:   xe  = xs + x;

183:   /* determine ghost region (Xs) and region scattered into (IXs)  */
184:   if (xs-sDist > 0) {
185:     Xs  = xs - sDist;
186:     IXs = xs - sDist;
187:   } else {
188:     if (bx) Xs = xs - sDist;
189:     else Xs = 0;
190:     IXs = 0;
191:   }
192:   if (xe+sDist <= M) {
193:     Xe  = xe + sDist;
194:     IXe = xe + sDist;
195:   } else {
196:     if (bx) Xe = xe + sDist;
197:     else Xe = M;
198:     IXe = M;
199:   }

201:   if (bx == DM_BOUNDARY_PERIODIC || bx == DM_BOUNDARY_MIRROR) {
202:     Xs  = xs - sDist;
203:     Xe  = xe + sDist;
204:     IXs = xs - sDist;
205:     IXe = xe + sDist;
206:   }

208:   /* allocate the base parallel and sequential vectors */
209:   dd->Nlocal = dof*x;
210:   VecCreateMPIWithArray(comm,dof,dd->Nlocal,PETSC_DECIDE,NULL,&global);
211:   dd->nlocal = dof*(Xe-Xs);
212:   VecCreateSeqWithArray(PETSC_COMM_SELF,dof,dd->nlocal,NULL,&local);

214:   VecGetOwnershipRange(global,&start,NULL);

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

220:   PetscMalloc1(x+2*sDist,&idx);
221:   PetscLogObjectMemory((PetscObject)da,(x+2*(sDist))*sizeof(PetscInt));

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

225:   nn = IXs-Xs;
226:   if (bx == DM_BOUNDARY_PERIODIC) { /* Handle all cases with periodic first */
227:     for (i=0; i<sDist; i++) {  /* Left ghost points */
228:       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
229:       else                 idx[nn++] = M+(xs-sDist+i);
230:     }

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

234:     for (i=0; i<sDist; i++) { /* Right ghost points */
235:       if ((xe+i)<M) idx [nn++] =  xe+i;
236:       else          idx [nn++] = (xe+i) - M;
237:     }
238:   } else if (bx == DM_BOUNDARY_MIRROR) { /* Handle all cases with periodic first */
239:     for (i=0; i<(sDist); i++) {  /* Left ghost points */
240:       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
241:       else                 idx[nn++] = sDist - i;
242:     }

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

246:     for (i=0; i<(sDist); i++) { /* Right ghost points */
247:       if ((xe+i)<M) idx[nn++] =  xe+i;
248:       else          idx[nn++] = M - (i + 1);
249:     }
250:   } else {      /* Now do all cases with no periodicity */
251:     if (0 <= xs-sDist) {
252:       for (i=0; i<sDist; i++) idx[nn++] = xs - sDist + i;
253:     } else {
254:       for (i=0; i<xs; i++) idx[nn++] = i;
255:     }

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

259:     if ((xe+sDist)<=M) {
260:       for (i=0; i<sDist; i++) idx[nn++]=xe+i;
261:     } else {
262:       for (i=xe; i<M; i++) idx[nn++]=i;
263:     }
264:   }

266:   ISCreateBlock(comm,dof,nn-IXs+Xs,&idx[IXs-Xs],PETSC_USE_POINTER,&from);
267:   VecScatterCreate(global,from,local,to,&gtol);
268:   PetscLogObjectParent((PetscObject)da,(PetscObject)gtol);
269:   ISDestroy(&to);
270:   ISDestroy(&from);
271:   VecDestroy(&local);
272:   VecDestroy(&global);

274:   dd->xs = dof*xs; dd->xe = dof*xe; dd->ys = 0; dd->ye = 1; dd->zs = 0; dd->ze = 1;
275:   dd->Xs = dof*Xs; dd->Xe = dof*Xe; dd->Ys = 0; dd->Ye = 1; dd->Zs = 0; dd->Ze = 1;

277:   dd->gtol      = gtol;
278:   dd->base      = dof*xs;
279:   da->ops->view = DMView_DA_1d;

281:   /*
282:      Set the local to global ordering in the global vector, this allows use
283:      of VecSetValuesLocal().
284:   */
285:   for (i=0; i<Xe-IXe; i++) idx[nn++] = -1; /* pad with -1s if needed for ghosted case*/

287:   ISLocalToGlobalMappingCreate(comm,dof,nn,idx,PETSC_OWN_POINTER,&da->ltogmap);
288:   PetscLogObjectParent((PetscObject)da,(PetscObject)da->ltogmap);

290:   return(0);
291: }


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

300:    Collective on MPI_Comm

302:    Input Parameters:
303: +  comm - MPI communicator
304: .  bx - type of ghost cells at the boundary the array should have, if any. Use
305:           DM_BOUNDARY_NONE, DM_BOUNDARY_GHOSTED, or DM_BOUNDARY_PERIODIC.
306: .  M - global dimension of the array (use -M to indicate that it may be set to a different value
307:             from the command line with -da_grid_x <M>)
308: .  dof - number of degrees of freedom per node
309: .  s - stencil width
310: -  lx - array containing number of nodes in the X direction on each processor,
311:         or NULL. If non-null, must be of length as the number of processes in the MPI_Comm.

313:    Output Parameter:
314: .  da - the resulting distributed array object

316:    Options Database Key:
317: +  -dm_view - Calls DMView() at the conclusion of DMDACreate1d()
318: .  -da_grid_x <nx> - number of grid points in x direction; can set if M < 0
319: .  -da_refine_x <rx> - refinement factor
320: -  -da_refine <n> - refine the DMDA n times before creating it, if M < 0

322:    Level: beginner

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

329: .keywords: distributed array, create, one-dimensional

331: .seealso: DMDestroy(), DMView(), DMDACreate2d(), DMDACreate3d(), DMGlobalToLocalBegin(), DMDASetRefinementFactor(),
332:           DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMLocalToLocalBegin(), DMLocalToLocalEnd(), DMDAGetRefinementFactor(),
333:           DMDAGetInfo(), DMCreateGlobalVector(), DMCreateLocalVector(), DMDACreateNaturalVector(), DMLoad(), DMDAGetOwnershipRanges()

335: @*/
336: PetscErrorCode  DMDACreate1d(MPI_Comm comm, DMBoundaryType bx, PetscInt M, PetscInt dof, PetscInt s, const PetscInt lx[], DM *da)
337: {
339:   PetscMPIInt    size;

342:   DMDACreate(comm, da);
343:   DMSetDimension(*da, 1);
344:   DMDASetSizes(*da, M, 1, 1);
345:   MPI_Comm_size(comm, &size);
346:   DMDASetNumProcs(*da, size, PETSC_DECIDE, PETSC_DECIDE);
347:   DMDASetBoundaryType(*da, bx, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE);
348:   DMDASetDof(*da, dof);
349:   DMDASetStencilWidth(*da, s);
350:   DMDASetOwnershipRanges(*da, lx, NULL, NULL);
351:   /* This violates the behavior for other classes, but right now users expect negative dimensions to be handled this way */
352:   DMSetFromOptions(*da);
353:   DMSetUp(*da);
354:   return(0);
355: }