Actual source code: da1.c

petsc-master 2018-05-20
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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>

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

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

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

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

 73:     PetscViewerDrawGetDraw(viewer,0,&draw);
 74:     PetscDrawIsNull(draw,&isnull);
 75:     if (isnull) return(0);

 77:     PetscDrawCheckResizedWindow(draw);
 78:     PetscDrawClear(draw);
 79:     PetscDrawSetCoordinates(draw,xmin,ymin,xmax,ymax);

 81:     PetscDrawCollectiveBegin(draw);
 82:     /* first processor draws all node lines */
 83:     if (!rank) {
 84:       PetscInt xmin_tmp;
 85:       ymin = 0.0; ymax = 0.3;
 86:       for (xmin_tmp=0; xmin_tmp < dd->M; xmin_tmp++) {
 87:         PetscDrawLine(draw,(double)xmin_tmp,ymin,(double)xmin_tmp,ymax,PETSC_DRAW_BLACK);
 88:       }
 89:       xmin = 0.0; xmax = dd->M - 1;
 90:       PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_BLACK);
 91:       PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_BLACK);
 92:     }
 93:     PetscDrawCollectiveEnd(draw);
 94:     PetscDrawFlush(draw);
 95:     PetscDrawPause(draw);

 97:     PetscDrawCollectiveBegin(draw);
 98:     /* draw my box */
 99:     ymin = 0; ymax = 0.3; xmin = dd->xs / dd->w; xmax = (dd->xe / dd->w)  - 1;
100:     PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_RED);
101:     PetscDrawLine(draw,xmin,ymin,xmin,ymax,PETSC_DRAW_RED);
102:     PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_RED);
103:     PetscDrawLine(draw,xmax,ymin,xmax,ymax,PETSC_DRAW_RED);
104:     /* Put in index numbers */
105:     base = dd->base / dd->w;
106:     for (x=xmin; x<=xmax; x++) {
107:       PetscSNPrintf(node,sizeof(node),"%d",(int)base++);
108:       PetscDrawString(draw,x,ymin,PETSC_DRAW_RED,node);
109:     }
110:     PetscDrawCollectiveEnd(draw);
111:     PetscDrawFlush(draw);
112:     PetscDrawPause(draw);
113:     PetscDrawSave(draw);
114:   } else if (isglvis) {
115:     DMView_DA_GLVis(da,viewer);
116:   } else if (isbinary) {
117:     DMView_DA_Binary(da,viewer);
118: #if defined(PETSC_HAVE_MATLAB_ENGINE)
119:   } else if (ismatlab) {
120:     DMView_DA_Matlab(da,viewer);
121: #endif
122:   }
123:   return(0);
124: }


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

146:   PetscObjectGetComm((PetscObject) da, &comm);
147:   MPI_Comm_size(comm,&size);
148:   MPI_Comm_rank(comm,&rank);

150:   dd->p = 1;
151:   dd->n = 1;
152:   dd->m = size;
153:   m     = dd->m;

155:   if (s > 0) {
156:     /* if not communicating data then should be ok to have nothing on some processes */
157:     if (M < m) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"More processes than data points! %D %D",m,M);
158:     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);
159:   }

161:   /*
162:      Determine locally owned region
163:      xs is the first local node number, x is the number of local nodes
164:   */
165:   if (!lx) {
166:     PetscMalloc1(m, &dd->lx);
167:     PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_blockcomm",&flg1,NULL);
168:     PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_nodes_at_end",&flg2,NULL);
169:     if (flg1) {      /* Block Comm type Distribution */
170:       xs = rank*M/m;
171:       x  = (rank + 1)*M/m - xs;
172:     } else if (flg2) { /* The odd nodes are evenly distributed across last nodes */
173:       x = (M + rank)/m;
174:       if (M/m == x) xs = rank*x;
175:       else          xs = rank*(x-1) + (M+rank)%(x*m);
176:     } else { /* The odd nodes are evenly distributed across the first k nodes */
177:       /* Regular PETSc Distribution */
178:       x = M/m + ((M % m) > rank);
179:       if (rank >= (M % m)) xs = (rank * (PetscInt)(M/m) + M % m);
180:       else                 xs = rank * (PetscInt)(M/m) + rank;
181:     }
182:     MPI_Allgather(&xs,1,MPIU_INT,dd->lx,1,MPIU_INT,comm);
183:     for (i=0; i<m-1; i++) dd->lx[i] = dd->lx[i+1] - dd->lx[i];
184:     dd->lx[m-1] = M - dd->lx[m-1];
185:   } else {
186:     x  = lx[rank];
187:     xs = 0;
188:     for (i=0; i<rank; i++) xs += lx[i];
189:     /* verify that data user provided is consistent */
190:     left = xs;
191:     for (i=rank; i<size; i++) left += lx[i];
192:     if (left != M) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Sum of lx across processors not equal to M %D %D",left,M);
193:   }

195:   /*
196:    check if the scatter requires more than one process neighbor or wraps around
197:    the domain more than once
198:   */
199:   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);

201:   xe  = xs + x;

203:   /* determine ghost region (Xs) and region scattered into (IXs)  */
204:   if (xs-sDist > 0) {
205:     Xs  = xs - sDist;
206:     IXs = xs - sDist;
207:   } else {
208:     if (bx) Xs = xs - sDist;
209:     else Xs = 0;
210:     IXs = 0;
211:   }
212:   if (xe+sDist <= M) {
213:     Xe  = xe + sDist;
214:     IXe = xe + sDist;
215:   } else {
216:     if (bx) Xe = xe + sDist;
217:     else Xe = M;
218:     IXe = M;
219:   }

221:   if (bx == DM_BOUNDARY_PERIODIC || bx == DM_BOUNDARY_MIRROR) {
222:     Xs  = xs - sDist;
223:     Xe  = xe + sDist;
224:     IXs = xs - sDist;
225:     IXe = xe + sDist;
226:   }

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

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

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

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

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

245:   nn = IXs-Xs;
246:   if (bx == DM_BOUNDARY_PERIODIC) { /* Handle all cases with periodic first */
247:     for (i=0; i<sDist; i++) {  /* Left ghost points */
248:       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
249:       else                 idx[nn++] = M+(xs-sDist+i);
250:     }

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

254:     for (i=0; i<sDist; i++) { /* Right ghost points */
255:       if ((xe+i)<M) idx [nn++] =  xe+i;
256:       else          idx [nn++] = (xe+i) - M;
257:     }
258:   } else if (bx == DM_BOUNDARY_MIRROR) { /* Handle all cases with periodic first */
259:     for (i=0; i<(sDist); i++) {  /* Left ghost points */
260:       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
261:       else                 idx[nn++] = sDist - i;
262:     }

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

266:     for (i=0; i<(sDist); i++) { /* Right ghost points */
267:       if ((xe+i)<M) idx[nn++] =  xe+i;
268:       else          idx[nn++] = M - (i + 2);
269:     }
270:   } else {      /* Now do all cases with no periodicity */
271:     if (0 <= xs-sDist) {
272:       for (i=0; i<sDist; i++) idx[nn++] = xs - sDist + i;
273:     } else {
274:       for (i=0; i<xs; i++) idx[nn++] = i;
275:     }

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

279:     if ((xe+sDist)<=M) {
280:       for (i=0; i<sDist; i++) idx[nn++]=xe+i;
281:     } else {
282:       for (i=xe; i<M; i++) idx[nn++]=i;
283:     }
284:   }

286:   ISCreateBlock(comm,dof,nn-IXs+Xs,&idx[IXs-Xs],PETSC_USE_POINTER,&from);
287:   VecScatterCreate(global,from,local,to,&gtol);
288:   PetscLogObjectParent((PetscObject)da,(PetscObject)gtol);
289:   ISDestroy(&to);
290:   ISDestroy(&from);
291:   VecDestroy(&local);
292:   VecDestroy(&global);

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

297:   dd->gtol      = gtol;
298:   dd->base      = dof*xs;
299:   da->ops->view = DMView_DA_1d;

301:   /*
302:      Set the local to global ordering in the global vector, this allows use
303:      of VecSetValuesLocal().
304:   */
305:   for (i=0; i<Xe-IXe; i++) idx[nn++] = -1; /* pad with -1s if needed for ghosted case*/

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

310:   return(0);
311: }


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

318:    Collective on MPI_Comm

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

332:    Output Parameter:
333: .  da - the resulting distributed array object

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

341:    Level: beginner

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

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

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

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

355: .seealso: DMDestroy(), DMView(), DMDACreate2d(), DMDACreate3d(), DMGlobalToLocalBegin(), DMDASetRefinementFactor(),
356:           DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMLocalToLocalBegin(), DMLocalToLocalEnd(), DMDAGetRefinementFactor(),
357:           DMDAGetInfo(), DMCreateGlobalVector(), DMCreateLocalVector(), DMDACreateNaturalVector(), DMLoad(), DMDAGetOwnershipRanges()

359: @*/
360: PetscErrorCode  DMDACreate1d(MPI_Comm comm, DMBoundaryType bx, PetscInt M, PetscInt dof, PetscInt s, const PetscInt lx[], DM *da)
361: {
363:   PetscMPIInt    size;

366:   DMDACreate(comm, da);
367:   DMSetDimension(*da, 1);
368:   DMDASetSizes(*da, M, 1, 1);
369:   MPI_Comm_size(comm, &size);
370:   DMDASetNumProcs(*da, size, PETSC_DECIDE, PETSC_DECIDE);
371:   DMDASetBoundaryType(*da, bx, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE);
372:   DMDASetDof(*da, dof);
373:   DMDASetStencilWidth(*da, s);
374:   DMDASetOwnershipRanges(*da, lx, NULL, NULL);
375:   return(0);
376: }