xref: /petsc/src/dm/impls/da/da1.c (revision 3de71b31db709282ed802e6ac0677e6c8e42aed3)
1 
2 /*
3    Code for manipulating distributed regular 1d arrays in parallel.
4    This file was created by Peter Mell   6/30/95
5 */
6 
7 #include <petsc/private/dmdaimpl.h>     /*I  "petscdmda.h"   I*/
8 
9 #include <petscdraw.h>
10 static PetscErrorCode DMView_DA_1d(DM da,PetscViewer viewer)
11 {
12   PetscErrorCode ierr;
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
19 
20   PetscFunctionBegin;
21   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)da),&rank);CHKERRQ(ierr);
22 
23   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
24   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
25   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERGLVIS,&isglvis);CHKERRQ(ierr);
26   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
27 #if defined(PETSC_HAVE_MATLAB_ENGINE)
28   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERMATLAB,&ismatlab);CHKERRQ(ierr);
29 #endif
30   if (iascii) {
31     PetscViewerFormat format;
32 
33     ierr = PetscViewerGetFormat(viewer, &format);CHKERRQ(ierr);
34     if (format != PETSC_VIEWER_ASCII_VTK && format != PETSC_VIEWER_ASCII_VTK_CELL && format != PETSC_VIEWER_ASCII_GLVIS) {
35       DMDALocalInfo info;
36       ierr = DMDAGetLocalInfo(da,&info);CHKERRQ(ierr);
37       ierr = PetscViewerASCIIPushSynchronized(viewer);CHKERRQ(ierr);
38       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"Processor [%d] M %D m %D w %D s %D\n",rank,dd->M,dd->m,dd->w,dd->s);CHKERRQ(ierr);
39       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"X range of indices: %D %D\n",info.xs,info.xs+info.xm);CHKERRQ(ierr);
40       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
41       ierr = PetscViewerASCIIPopSynchronized(viewer);CHKERRQ(ierr);
42     } else if (format == PETSC_VIEWER_ASCII_GLVIS) {
43       ierr = DMView_DA_GLVis(da,viewer);CHKERRQ(ierr);
44     } else {
45       ierr = DMView_DA_VTK(da, viewer);CHKERRQ(ierr);
46     }
47   } else if (isdraw) {
48     PetscDraw draw;
49     double    ymin = -1,ymax = 1,xmin = -1,xmax = dd->M,x;
50     PetscInt  base;
51     char      node[10];
52     PetscBool isnull;
53 
54     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
55     ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr);
56     if (isnull) PetscFunctionReturn(0);
57 
58     ierr = PetscDrawCheckResizedWindow(draw);CHKERRQ(ierr);
59     ierr = PetscDrawClear(draw);CHKERRQ(ierr);
60     ierr = PetscDrawSetCoordinates(draw,xmin,ymin,xmax,ymax);CHKERRQ(ierr);
61 
62     ierr = PetscDrawCollectiveBegin(draw);CHKERRQ(ierr);
63     /* first processor draws all node lines */
64     if (!rank) {
65       PetscInt xmin_tmp;
66       ymin = 0.0; ymax = 0.3;
67       for (xmin_tmp=0; xmin_tmp < dd->M; xmin_tmp++) {
68         ierr = PetscDrawLine(draw,(double)xmin_tmp,ymin,(double)xmin_tmp,ymax,PETSC_DRAW_BLACK);CHKERRQ(ierr);
69       }
70       xmin = 0.0; xmax = dd->M - 1;
71       ierr = PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_BLACK);CHKERRQ(ierr);
72       ierr = PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_BLACK);CHKERRQ(ierr);
73     }
74     ierr = PetscDrawCollectiveEnd(draw);CHKERRQ(ierr);
75     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
76     ierr = PetscDrawPause(draw);CHKERRQ(ierr);
77 
78     ierr = PetscDrawCollectiveBegin(draw);CHKERRQ(ierr);
79     /* draw my box */
80     ymin = 0; ymax = 0.3; xmin = dd->xs / dd->w; xmax = (dd->xe / dd->w)  - 1;
81     ierr = PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_RED);CHKERRQ(ierr);
82     ierr = PetscDrawLine(draw,xmin,ymin,xmin,ymax,PETSC_DRAW_RED);CHKERRQ(ierr);
83     ierr = PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_RED);CHKERRQ(ierr);
84     ierr = PetscDrawLine(draw,xmax,ymin,xmax,ymax,PETSC_DRAW_RED);CHKERRQ(ierr);
85     /* Put in index numbers */
86     base = dd->base / dd->w;
87     for (x=xmin; x<=xmax; x++) {
88       ierr = PetscSNPrintf(node,sizeof(node),"%d",(int)base++);CHKERRQ(ierr);
89       ierr = PetscDrawString(draw,x,ymin,PETSC_DRAW_RED,node);CHKERRQ(ierr);
90     }
91     ierr = PetscDrawCollectiveEnd(draw);CHKERRQ(ierr);
92     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
93     ierr = PetscDrawPause(draw);CHKERRQ(ierr);
94     ierr = PetscDrawSave(draw);CHKERRQ(ierr);
95   } else if (isglvis) {
96     ierr = DMView_DA_GLVis(da,viewer);CHKERRQ(ierr);
97   } else if (isbinary) {
98     ierr = DMView_DA_Binary(da,viewer);CHKERRQ(ierr);
99 #if defined(PETSC_HAVE_MATLAB_ENGINE)
100   } else if (ismatlab) {
101     ierr = DMView_DA_Matlab(da,viewer);CHKERRQ(ierr);
102 #endif
103   }
104   PetscFunctionReturn(0);
105 }
106 
107 
108 PetscErrorCode  DMSetUp_DA_1D(DM da)
109 {
110   DM_DA            *dd   = (DM_DA*)da->data;
111   const PetscInt   M     = dd->M;
112   const PetscInt   dof   = dd->w;
113   const PetscInt   s     = dd->s;
114   const PetscInt   sDist = s;  /* stencil distance in points */
115   const PetscInt   *lx   = dd->lx;
116   DMBoundaryType   bx    = dd->bx;
117   MPI_Comm         comm;
118   Vec              local, global;
119   VecScatter       gtol;
120   IS               to, from;
121   PetscBool        flg1 = PETSC_FALSE, flg2 = PETSC_FALSE;
122   PetscMPIInt      rank, size;
123   PetscInt         i,*idx,nn,left,xs,xe,x,Xs,Xe,start,m,IXs,IXe;
124   PetscErrorCode   ierr;
125 
126   PetscFunctionBegin;
127   ierr = PetscObjectGetComm((PetscObject) da, &comm);CHKERRQ(ierr);
128   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
129   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
130 
131   dd->p = 1;
132   dd->n = 1;
133   dd->m = size;
134   m     = dd->m;
135 
136   if (s > 0) {
137     /* if not communicating data then should be ok to have nothing on some processes */
138     if (M < m) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"More processes than data points! %D %D",m,M);
139     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);
140   }
141 
142   /*
143      Determine locally owned region
144      xs is the first local node number, x is the number of local nodes
145   */
146   if (!lx) {
147     ierr = PetscMalloc1(m, &dd->lx);CHKERRQ(ierr);
148     ierr = PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_blockcomm",&flg1,NULL);CHKERRQ(ierr);
149     ierr = PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_nodes_at_end",&flg2,NULL);CHKERRQ(ierr);
150     if (flg1) {      /* Block Comm type Distribution */
151       xs = rank*M/m;
152       x  = (rank + 1)*M/m - xs;
153     } else if (flg2) { /* The odd nodes are evenly distributed across last nodes */
154       x = (M + rank)/m;
155       if (M/m == x) xs = rank*x;
156       else          xs = rank*(x-1) + (M+rank)%(x*m);
157     } else { /* The odd nodes are evenly distributed across the first k nodes */
158       /* Regular PETSc Distribution */
159       x = M/m + ((M % m) > rank);
160       if (rank >= (M % m)) xs = (rank * (PetscInt)(M/m) + M % m);
161       else                 xs = rank * (PetscInt)(M/m) + rank;
162     }
163     ierr = MPI_Allgather(&xs,1,MPIU_INT,dd->lx,1,MPIU_INT,comm);CHKERRQ(ierr);
164     for (i=0; i<m-1; i++) dd->lx[i] = dd->lx[i+1] - dd->lx[i];
165     dd->lx[m-1] = M - dd->lx[m-1];
166   } else {
167     x  = lx[rank];
168     xs = 0;
169     for (i=0; i<rank; i++) xs += lx[i];
170     /* verify that data user provided is consistent */
171     left = xs;
172     for (i=rank; i<size; i++) left += lx[i];
173     if (left != M) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Sum of lx across processors not equal to M %D %D",left,M);
174   }
175 
176   /*
177    check if the scatter requires more than one process neighbor or wraps around
178    the domain more than once
179   */
180   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 
182   xe  = xs + x;
183 
184   /* determine ghost region (Xs) and region scattered into (IXs)  */
185   if (xs-sDist > 0) {
186     Xs  = xs - sDist;
187     IXs = xs - sDist;
188   } else {
189     if (bx) Xs = xs - sDist;
190     else Xs = 0;
191     IXs = 0;
192   }
193   if (xe+sDist <= M) {
194     Xe  = xe + sDist;
195     IXe = xe + sDist;
196   } else {
197     if (bx) Xe = xe + sDist;
198     else Xe = M;
199     IXe = M;
200   }
201 
202   if (bx == DM_BOUNDARY_PERIODIC || bx == DM_BOUNDARY_MIRROR) {
203     Xs  = xs - sDist;
204     Xe  = xe + sDist;
205     IXs = xs - sDist;
206     IXe = xe + sDist;
207   }
208 
209   /* allocate the base parallel and sequential vectors */
210   dd->Nlocal = dof*x;
211   ierr       = VecCreateMPIWithArray(comm,dof,dd->Nlocal,PETSC_DECIDE,NULL,&global);CHKERRQ(ierr);
212   dd->nlocal = dof*(Xe-Xs);
213   ierr       = VecCreateSeqWithArray(PETSC_COMM_SELF,dof,dd->nlocal,NULL,&local);CHKERRQ(ierr);
214 
215   ierr = VecGetOwnershipRange(global,&start,NULL);CHKERRQ(ierr);
216 
217   /* Create Global to Local Vector Scatter Context */
218   /* global to local must retrieve ghost points */
219   ierr = ISCreateStride(comm,dof*(IXe-IXs),dof*(IXs-Xs),1,&to);CHKERRQ(ierr);
220 
221   ierr = PetscMalloc1(x+2*sDist,&idx);CHKERRQ(ierr);
222   ierr = PetscLogObjectMemory((PetscObject)da,(x+2*(sDist))*sizeof(PetscInt));CHKERRQ(ierr);
223 
224   for (i=0; i<IXs-Xs; i++) idx[i] = -1; /* prepend with -1s if needed for ghosted case*/
225 
226   nn = IXs-Xs;
227   if (bx == DM_BOUNDARY_PERIODIC) { /* Handle all cases with periodic first */
228     for (i=0; i<sDist; i++) {  /* Left ghost points */
229       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
230       else                 idx[nn++] = M+(xs-sDist+i);
231     }
232 
233     for (i=0; i<x; i++) idx [nn++] = xs + i;  /* Non-ghost points */
234 
235     for (i=0; i<sDist; i++) { /* Right ghost points */
236       if ((xe+i)<M) idx [nn++] =  xe+i;
237       else          idx [nn++] = (xe+i) - M;
238     }
239   } else if (bx == DM_BOUNDARY_MIRROR) { /* Handle all cases with periodic first */
240     for (i=0; i<(sDist); i++) {  /* Left ghost points */
241       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
242       else                 idx[nn++] = sDist - i;
243     }
244 
245     for (i=0; i<x; i++) idx [nn++] = xs + i;  /* Non-ghost points */
246 
247     for (i=0; i<(sDist); i++) { /* Right ghost points */
248       if ((xe+i)<M) idx[nn++] =  xe+i;
249       else          idx[nn++] = M - (i + 2);
250     }
251   } else {      /* Now do all cases with no periodicity */
252     if (0 <= xs-sDist) {
253       for (i=0; i<sDist; i++) idx[nn++] = xs - sDist + i;
254     } else {
255       for (i=0; i<xs; i++) idx[nn++] = i;
256     }
257 
258     for (i=0; i<x; i++) idx [nn++] = xs + i;
259 
260     if ((xe+sDist)<=M) {
261       for (i=0; i<sDist; i++) idx[nn++]=xe+i;
262     } else {
263       for (i=xe; i<M; i++) idx[nn++]=i;
264     }
265   }
266 
267   ierr = ISCreateBlock(comm,dof,nn-IXs+Xs,&idx[IXs-Xs],PETSC_USE_POINTER,&from);CHKERRQ(ierr);
268   ierr = VecScatterCreate(global,from,local,to,&gtol);CHKERRQ(ierr);
269   ierr = PetscLogObjectParent((PetscObject)da,(PetscObject)gtol);CHKERRQ(ierr);
270   ierr = ISDestroy(&to);CHKERRQ(ierr);
271   ierr = ISDestroy(&from);CHKERRQ(ierr);
272   ierr = VecDestroy(&local);CHKERRQ(ierr);
273   ierr = VecDestroy(&global);CHKERRQ(ierr);
274 
275   dd->xs = dof*xs; dd->xe = dof*xe; dd->ys = 0; dd->ye = 1; dd->zs = 0; dd->ze = 1;
276   dd->Xs = dof*Xs; dd->Xe = dof*Xe; dd->Ys = 0; dd->Ye = 1; dd->Zs = 0; dd->Ze = 1;
277 
278   dd->gtol      = gtol;
279   dd->base      = dof*xs;
280   da->ops->view = DMView_DA_1d;
281 
282   /*
283      Set the local to global ordering in the global vector, this allows use
284      of VecSetValuesLocal().
285   */
286   for (i=0; i<Xe-IXe; i++) idx[nn++] = -1; /* pad with -1s if needed for ghosted case*/
287 
288   ierr = ISLocalToGlobalMappingCreate(comm,dof,nn,idx,PETSC_OWN_POINTER,&da->ltogmap);CHKERRQ(ierr);
289   ierr = PetscLogObjectParent((PetscObject)da,(PetscObject)da->ltogmap);CHKERRQ(ierr);
290 
291   PetscFunctionReturn(0);
292 }
293 
294 
295 /*@C
296    DMDACreate1d - Creates an object that will manage the communication of  one-dimensional
297    regular array data that is distributed across some processors.
298 
299    Collective on MPI_Comm
300 
301    Input Parameters:
302 +  comm - MPI communicator
303 .  bx - type of ghost cells at the boundary the array should have, if any. Use
304           DM_BOUNDARY_NONE, DM_BOUNDARY_GHOSTED, or DM_BOUNDARY_PERIODIC.
305 .  M - global dimension of the array
306             from the command line with -da_grid_x <M>)
307 .  dof - number of degrees of freedom per node
308 .  s - stencil width
309 -  lx - array containing number of nodes in the X direction on each processor,
310         or NULL. If non-null, must be of length as the number of processes in the MPI_Comm.
311 
312    Output Parameter:
313 .  da - the resulting distributed array object
314 
315    Options Database Key:
316 +  -dm_view - Calls DMView() at the conclusion of DMDACreate1d()
317 .  -da_grid_x <nx> - number of grid points in x direction; can set if M < 0
318 .  -da_refine_x <rx> - refinement factor
319 -  -da_refine <n> - refine the DMDA n times before creating it, if M < 0
320 
321    Level: beginner
322 
323    Notes:
324    The array data itself is NOT stored in the DMDA, it is stored in Vec objects;
325    The appropriate vector objects can be obtained with calls to DMCreateGlobalVector()
326    and DMCreateLocalVector() and calls to VecDuplicate() if more are needed.
327 
328    You must call DMSetUp() after this call before using this DM.
329 
330    If you wish to use the options database to change values in the DMDA call DMSetFromOptions() after this call
331    but before DMSetUp().
332 
333 .keywords: distributed array, create, one-dimensional
334 
335 .seealso: DMDestroy(), DMView(), DMDACreate2d(), DMDACreate3d(), DMGlobalToLocalBegin(), DMDASetRefinementFactor(),
336           DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMLocalToLocalBegin(), DMLocalToLocalEnd(), DMDAGetRefinementFactor(),
337           DMDAGetInfo(), DMCreateGlobalVector(), DMCreateLocalVector(), DMDACreateNaturalVector(), DMLoad(), DMDAGetOwnershipRanges()
338 
339 @*/
340 PetscErrorCode  DMDACreate1d(MPI_Comm comm, DMBoundaryType bx, PetscInt M, PetscInt dof, PetscInt s, const PetscInt lx[], DM *da)
341 {
342   PetscErrorCode ierr;
343   PetscMPIInt    size;
344 
345   PetscFunctionBegin;
346   ierr = DMDACreate(comm, da);CHKERRQ(ierr);
347   ierr = DMSetDimension(*da, 1);CHKERRQ(ierr);
348   ierr = DMDASetSizes(*da, M, 1, 1);CHKERRQ(ierr);
349   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
350   ierr = DMDASetNumProcs(*da, size, PETSC_DECIDE, PETSC_DECIDE);CHKERRQ(ierr);
351   ierr = DMDASetBoundaryType(*da, bx, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE);CHKERRQ(ierr);
352   ierr = DMDASetDof(*da, dof);CHKERRQ(ierr);
353   ierr = DMDASetStencilWidth(*da, s);CHKERRQ(ierr);
354   ierr = DMDASetOwnershipRanges(*da, lx, NULL, NULL);CHKERRQ(ierr);
355   PetscFunctionReturn(0);
356 }
357