Actual source code: da1.c

  1: #define PETSCDM_DLL
  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 src/dm/da/daimpl.h

 11: PetscErrorCode DAView_1d(DA da,PetscViewer viewer)
 12: {
 14:   PetscMPIInt    rank;
 15:   PetscTruth     iascii,isdraw;

 18:   MPI_Comm_rank(da->comm,&rank);

 20:   PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&iascii);
 21:   PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_DRAW,&isdraw);
 22:   if (iascii) {
 23:     PetscViewerASCIISynchronizedPrintf(viewer,"Processor [%d] M %D m %D w %D s %D\n",rank,da->M,
 24:                  da->m,da->w,da->s);
 25:     PetscViewerASCIISynchronizedPrintf(viewer,"X range of indices: %D %D\n",da->xs,da->xe);
 26:     PetscViewerFlush(viewer);
 27:   } else if (isdraw) {
 28:     PetscDraw       draw;
 29:     double     ymin = -1,ymax = 1,xmin = -1,xmax = da->M,x;
 30:     PetscInt        base;
 31:     char       node[10];
 32:     PetscTruth isnull;

 34:     PetscViewerDrawGetDraw(viewer,0,&draw);
 35:     PetscDrawIsNull(draw,&isnull); if (isnull) return(0);

 37:     PetscDrawSetCoordinates(draw,xmin,ymin,xmax,ymax);
 38:     PetscDrawSynchronizedClear(draw);

 40:     /* first processor draws all node lines */
 41:     if (!rank) {
 42:       PetscInt xmin_tmp;
 43:       ymin = 0.0; ymax = 0.3;
 44: 
 45:       /* ADIC doesn't like doubles in a for loop */
 46:       for (xmin_tmp =0; xmin_tmp < da->M; xmin_tmp++) {
 47:          PetscDrawLine(draw,(double)xmin_tmp,ymin,(double)xmin_tmp,ymax,PETSC_DRAW_BLACK);
 48:       }

 50:       xmin = 0.0; xmax = da->M - 1;
 51:       PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_BLACK);
 52:       PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_BLACK);
 53:     }

 55:     PetscDrawSynchronizedFlush(draw);
 56:     PetscDrawPause(draw);

 58:     /* draw my box */
 59:     ymin = 0; ymax = 0.3; xmin = da->xs / da->w; xmax = (da->xe / da->w)  - 1;
 60:     PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_RED);
 61:     PetscDrawLine(draw,xmin,ymin,xmin,ymax,PETSC_DRAW_RED);
 62:     PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_RED);
 63:     PetscDrawLine(draw,xmax,ymin,xmax,ymax,PETSC_DRAW_RED);

 65:     /* Put in index numbers */
 66:     base = da->base / da->w;
 67:     for (x=xmin; x<=xmax; x++) {
 68:       sprintf(node,"%d",(int)base++);
 69:       PetscDrawString(draw,x,ymin,PETSC_DRAW_RED,node);
 70:     }

 72:     PetscDrawSynchronizedFlush(draw);
 73:     PetscDrawPause(draw);
 74:   } else {
 75:     SETERRQ1(PETSC_ERR_SUP,"Viewer type %s not supported for DA 1d",((PetscObject)viewer)->type_name);
 76:   }
 77:   return(0);
 78: }

 80: EXTERN PetscErrorCode DAPublish_Petsc(PetscObject);

 84: /*@C
 85:    DACreate1d - Creates an object that will manage the communication of  one-dimensional 
 86:    regular array data that is distributed across some processors.

 88:    Collective on MPI_Comm

 90:    Input Parameters:
 91: +  comm - MPI communicator
 92: .  wrap - type of periodicity should the array have, if any. Use 
 93:           either DA_NONPERIODIC or DA_XPERIODIC
 94: .  M - global dimension of the array (use -M to indicate that it may be set to a different value 
 95:             from the command line with -da_grid_x <M>)
 96: .  dof - number of degrees of freedom per node
 97: .  lc - array containing number of nodes in the X direction on each processor, 
 98:         or PETSC_NULL. If non-null, must be of length as m.
 99: -  s - stencil width  

101:    Output Parameter:
102: .  inra - the resulting distributed array object

104:    Options Database Key:
105: +  -da_view - Calls DAView() at the conclusion of DACreate1d()
106: .  -da_grid_x <nx> - number of grid points in x direction; can set if M < 0
107: -  -da_refine_x - refinement factor 

109:    Level: beginner

111:    Notes:
112:    The array data itself is NOT stored in the DA, it is stored in Vec objects;
113:    The appropriate vector objects can be obtained with calls to DACreateGlobalVector()
114:    and DACreateLocalVector() and calls to VecDuplicate() if more are needed.


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

119: .seealso: DADestroy(), DAView(), DACreate2d(), DACreate3d(), DAGlobalToLocalBegin(), DASetRefinementFactor(),
120:           DAGlobalToLocalEnd(), DALocalToGlobal(), DALocalToLocalBegin(), DALocalToLocalEnd(), DAGetRefinementFactor(),
121:           DAGetInfo(), DACreateGlobalVector(), DACreateLocalVector(), DACreateNaturalVector(), DALoad(), DAView()

123: @*/
124: PetscErrorCode PETSCDM_DLLEXPORT DACreate1d(MPI_Comm comm,DAPeriodicType wrap,PetscInt M,PetscInt dof,PetscInt s,PetscInt *lc,DA *inra)
125: {
127:   PetscMPIInt    rank,size;
128:   PetscInt       i,*idx,nn,left,refine_x = 2,tM = M,xs,xe,x,Xs,Xe,start,end,m;
129:   PetscTruth     flg1,flg2;
130:   DA             da;
131:   Vec            local,global;
132:   VecScatter     ltog,gtol;
133:   IS             to,from;

137:   *inra = 0;
138: #ifndef PETSC_USE_DYNAMIC_LIBRARIES
139:   DMInitializePackage(PETSC_NULL);
140: #endif

142:   if (dof < 1) SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"Must have 1 or more degrees of freedom per node: %D",dof);
143:   if (s < 0) SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"Stencil width cannot be negative: %D",s);

145:   PetscOptionsBegin(comm,PETSC_NULL,"1d DA Options","DA");
146:     if (M < 0) {
147:       tM   = -M;
148:       PetscOptionsInt("-da_grid_x","Number of grid points in x direction","DACreate1d",tM,&tM,PETSC_NULL);
149:     }
150:     PetscOptionsInt("-da_refine_x","Refinement ratio in x direction","DASetRefinementFactor",refine_x,&refine_x,PETSC_NULL);
151:   PetscOptionsEnd();
152:   M = tM;

154:   PetscHeaderCreate(da,_p_DA,struct _DAOps,DA_COOKIE,0,"DA",comm,DADestroy,DAView);
155:   da->bops->publish           = DAPublish_Petsc;
156:   da->ops->createglobalvector = DACreateGlobalVector;
157:   da->ops->getinterpolation   = DAGetInterpolation;
158:   da->ops->getcoloring        = DAGetColoring;
159:   da->ops->getmatrix          = DAGetMatrix;
160:   da->ops->refine             = DARefine;
161:   PetscLogObjectMemory(da,sizeof(struct _p_DA));
162:   da->dim        = 1;
163:   da->interptype = DA_Q1;
164:   da->refine_x   = refine_x;
165:   PetscMalloc(dof*sizeof(char*),&da->fieldname);
166:   PetscMemzero(da->fieldname,dof*sizeof(char*));
167:   MPI_Comm_size(comm,&size);
168:   MPI_Comm_rank(comm,&rank);

170:   m = size;

172:   if (M < m)     SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"More processors than data points! %D %D",m,M);
173:   if ((M-1) < s) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Array is too small for stencil! %D %D",M-1,s);

175:   /* 
176:      Determine locally owned region 
177:      xs is the first local node number, x is the number of local nodes 
178:   */
179:   if (!lc) {
180:     PetscOptionsHasName(PETSC_NULL,"-da_partition_blockcomm",&flg1);
181:     PetscOptionsHasName(PETSC_NULL,"-da_partition_nodes_at_end",&flg2);
182:     if (flg1) {      /* Block Comm type Distribution */
183:       xs = rank*M/m;
184:       x  = (rank + 1)*M/m - xs;
185:     } else if (flg2) { /* The odd nodes are evenly distributed across last nodes */
186:       x = (M + rank)/m;
187:       if (M/m == x) { xs = rank*x; }
188:       else          { xs = rank*(x-1) + (M+rank)%(x*m); }
189:     } else { /* The odd nodes are evenly distributed across the first k nodes */
190:       /* Regular PETSc Distribution */
191:       x = M/m + ((M % m) > rank);
192:       if (rank >= (M % m)) {xs = (rank * (PetscInt)(M/m) + M % m);}
193:       else                 {xs = rank * (PetscInt)(M/m) + rank;}
194:     }
195:   } else {
196:     x  = lc[rank];
197:     xs = 0;
198:     for (i=0; i<rank; i++) {
199:       xs += lc[i];
200:     }
201:     /* verify that data user provided is consistent */
202:     left = xs;
203:     for (i=rank; i<size; i++) {
204:       left += lc[i];
205:     }
206:     if (left != M) {
207:       SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Sum of lc across processors not equal to M %D %D",left,M);
208:     }
209:   }

211:   /* From now on x,s,xs,xe,Xs,Xe are the exact location in the array */
212:   x  *= dof;
213:   s  *= dof;  /* NOTE: here change s to be absolute stencil distance */
214:   xs *= dof;
215:   xe = xs + x;

217:   /* determine ghost region */
218:   if (wrap == DA_XPERIODIC) {
219:     Xs = xs - s;
220:     Xe = xe + s;
221:   } else {
222:     if ((xs-s) >= 0)   Xs = xs-s;  else Xs = 0;
223:     if ((xe+s) <= M*dof) Xe = xe+s;  else Xe = M*dof;
224:   }

226:   /* allocate the base parallel and sequential vectors */
227:   da->Nlocal = x;
228:   VecCreateMPIWithArray(comm,da->Nlocal,PETSC_DECIDE,0,&global);
229:   VecSetBlockSize(global,dof);
230:   da->nlocal = (Xe-Xs);
231:   VecCreateSeqWithArray(PETSC_COMM_SELF,da->nlocal,0,&local);
232:   VecSetBlockSize(local,dof);
233: 
234:   /* Create Local to Global Vector Scatter Context */
235:   /* local to global inserts non-ghost point region into global */
236:   VecGetOwnershipRange(global,&start,&end);
237:   ISCreateStride(comm,x,start,1,&to);
238:   ISCreateStride(comm,x,xs-Xs,1,&from);
239:   VecScatterCreate(local,from,global,to,&ltog);
240:   PetscLogObjectParent(da,to);
241:   PetscLogObjectParent(da,from);
242:   PetscLogObjectParent(da,ltog);
243:   ISDestroy(from);
244:   ISDestroy(to);

246:   /* Create Global to Local Vector Scatter Context */
247:   /* global to local must retrieve ghost points */
248:   ISCreateStride(comm,(Xe-Xs),0,1,&to);
249: 
250:   PetscMalloc((x+2*s)*sizeof(PetscInt),&idx);
251:   PetscLogObjectMemory(da,(x+2*s)*sizeof(PetscInt));

253:   nn = 0;
254:   if (wrap == DA_XPERIODIC) {    /* Handle all cases with wrap first */

256:     for (i=0; i<s; i++) {  /* Left ghost points */
257:       if ((xs-s+i)>=0) { idx[nn++] = xs-s+i;}
258:       else             { idx[nn++] = M*dof+(xs-s+i);}
259:     }

261:     for (i=0; i<x; i++) { idx [nn++] = xs + i;}  /* Non-ghost points */
262: 
263:     for (i=0; i<s; i++) { /* Right ghost points */
264:       if ((xe+i)<M*dof) { idx [nn++] =  xe+i; }
265:       else            { idx [nn++] = (xe+i) - M*dof;}
266:     }
267:   } else {      /* Now do all cases with no wrapping */

269:     if (s <= xs) {for (i=0; i<s; i++) {idx[nn++] = xs - s + i;}}
270:     else         {for (i=0; i<xs;  i++) {idx[nn++] = i;}}

272:     for (i=0; i<x; i++) { idx [nn++] = xs + i;}
273: 
274:     if ((xe+s)<=M*dof) {for (i=0;  i<s;     i++) {idx[nn++]=xe+i;}}
275:     else             {for (i=xe; i<(M*dof); i++) {idx[nn++]=i;   }}
276:   }

278:   ISCreateGeneral(comm,nn,idx,&from);
279:   VecScatterCreate(global,from,local,to,&gtol);
280:   PetscLogObjectParent(da,to);
281:   PetscLogObjectParent(da,from);
282:   PetscLogObjectParent(da,gtol);
283:   ISDestroy(to);
284:   ISDestroy(from);
285:   VecDestroy(local);
286:   VecDestroy(global);

288:   da->M  = M;  da->N  = 1;  da->m  = m; da->n = 1;
289:   da->xs = xs; da->xe = xe; da->ys = 0; da->ye = 1; da->zs = 0; da->ze = 1;
290:   da->Xs = Xs; da->Xe = Xe; da->Ys = 0; da->Ye = 1; da->Zs = 0; da->Ze = 1;
291:   da->P  = 1;  da->p  = 1;  da->w = dof; da->s = s/dof;

293:   da->gtol         = gtol;
294:   da->ltog         = ltog;
295:   da->idx          = idx;
296:   da->Nl           = nn;
297:   da->base         = xs;
298:   da->ops->view    = DAView_1d;
299:   da->wrap         = wrap;
300:   da->stencil_type = DA_STENCIL_STAR;

302:   /* 
303:      Set the local to global ordering in the global vector, this allows use
304:      of VecSetValuesLocal().
305:   */
306:   ISLocalToGlobalMappingCreateNC(comm,nn,idx,&da->ltogmap);
307:   ISLocalToGlobalMappingBlock(da->ltogmap,da->w,&da->ltogmapb);
308:   PetscLogObjectParent(da,da->ltogmap);

310:   da->ltol = PETSC_NULL;
311:   da->ao   = PETSC_NULL;

313:   PetscOptionsHasName(PETSC_NULL,"-da_view",&flg1);
314:   if (flg1) {DAView(da,PETSC_VIEWER_STDOUT_(da->comm));}
315:   PetscOptionsHasName(PETSC_NULL,"-da_view_draw",&flg1);
316:   if (flg1) {DAView(da,PETSC_VIEWER_DRAW_(da->comm));}
317:   PetscOptionsHasName(PETSC_NULL,"-help",&flg1);
318:   if (flg1) {DAPrintHelp(da);}
319:   *inra = da;
320:   PetscPublishAll(da);
321:   return(0);
322: }