xref: /petsc/src/dm/impls/da/da1.c (revision c6228bba3efb3955e5e29a4ef79e8b65616d20d2)
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 #undef __FUNCT__
11 #define __FUNCT__ "DMView_DA_1d"
12 PetscErrorCode DMView_DA_1d(DM da,PetscViewer viewer)
13 {
14   PetscErrorCode ierr;
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
21 
22   PetscFunctionBegin;
23   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)da),&rank);CHKERRQ(ierr);
24 
25   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
26   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
27   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
28 #if defined(PETSC_HAVE_MATLAB_ENGINE)
29   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERMATLAB,&ismatlab);CHKERRQ(ierr);
30 #endif
31   if (iascii) {
32     PetscViewerFormat format;
33 
34     ierr = PetscViewerGetFormat(viewer, &format);CHKERRQ(ierr);
35     if (format != PETSC_VIEWER_ASCII_VTK && format != PETSC_VIEWER_ASCII_VTK_CELL) {
36       DMDALocalInfo info;
37       ierr = DMDAGetLocalInfo(da,&info);CHKERRQ(ierr);
38       ierr = PetscViewerASCIIPushSynchronized(viewer);CHKERRQ(ierr);
39       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);
40       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"X range of indices: %D %D\n",info.xs,info.xs+info.xm);CHKERRQ(ierr);
41       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
42       ierr = PetscViewerASCIIPopSynchronized(viewer);CHKERRQ(ierr);
43     } else {
44       ierr = DMView_DA_VTK(da, viewer);CHKERRQ(ierr);
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;
52 
53     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
54     ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr);
55     if (isnull) PetscFunctionReturn(0);
56 
57     ierr = PetscDrawCheckResizedWindow(draw);CHKERRQ(ierr);
58     ierr = PetscDrawClear(draw);CHKERRQ(ierr);
59 
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 
76     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
77     ierr = PetscDrawPause(draw);CHKERRQ(ierr);
78 
79     ierr = PetscDrawCollectiveBegin(draw);CHKERRQ(ierr);
80     /* draw my box */
81     ymin = 0; ymax = 0.3; xmin = dd->xs / dd->w; xmax = (dd->xe / dd->w)  - 1;
82     ierr = PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_RED);CHKERRQ(ierr);
83     ierr = PetscDrawLine(draw,xmin,ymin,xmin,ymax,PETSC_DRAW_RED);CHKERRQ(ierr);
84     ierr = PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_RED);CHKERRQ(ierr);
85     ierr = PetscDrawLine(draw,xmax,ymin,xmax,ymax,PETSC_DRAW_RED);CHKERRQ(ierr);
86     /* Put in index numbers */
87     base = dd->base / dd->w;
88     for (x=xmin; x<=xmax; x++) {
89       sprintf(node,"%d",(int)base++);
90       ierr = PetscDrawString(draw,x,ymin,PETSC_DRAW_RED,node);CHKERRQ(ierr);
91     }
92     ierr = PetscDrawCollectiveEnd(draw);CHKERRQ(ierr);
93 
94     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
95     ierr = PetscDrawPause(draw);CHKERRQ(ierr);
96   } else if (isbinary) {
97     ierr = DMView_DA_Binary(da,viewer);CHKERRQ(ierr);
98 #if defined(PETSC_HAVE_MATLAB_ENGINE)
99   } else if (ismatlab) {
100     ierr = DMView_DA_Matlab(da,viewer);CHKERRQ(ierr);
101 #endif
102   }
103   PetscFunctionReturn(0);
104 }
105 
106 
107 #undef __FUNCT__
108 #define __FUNCT__ "DMSetUp_DA_1D"
109 PetscErrorCode  DMSetUp_DA_1D(DM da)
110 {
111   DM_DA            *dd   = (DM_DA*)da->data;
112   const PetscInt   M     = dd->M;
113   const PetscInt   dof   = dd->w;
114   const PetscInt   s     = dd->s;
115   const PetscInt   sDist = s;  /* stencil distance in points */
116   const PetscInt   *lx   = dd->lx;
117   DMBoundaryType   bx    = dd->bx;
118   MPI_Comm         comm;
119   Vec              local, global;
120   VecScatter       gtol;
121   IS               to, from;
122   PetscBool        flg1 = PETSC_FALSE, flg2 = PETSC_FALSE;
123   PetscMPIInt      rank, size;
124   PetscInt         i,*idx,nn,left,xs,xe,x,Xs,Xe,start,m,IXs,IXe;
125   PetscErrorCode   ierr;
126 
127   PetscFunctionBegin;
128   ierr = PetscObjectGetComm((PetscObject) da, &comm);CHKERRQ(ierr);
129   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
130   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
131 
132   dd->p = 1;
133   dd->n = 1;
134   dd->m = size;
135   m     = dd->m;
136 
137   if (s > 0) {
138     /* if not communicating data then should be ok to have nothing on some processes */
139     if (M < m) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"More processes than data points! %D %D",m,M);
140     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);
141   }
142 
143   /*
144      Determine locally owned region
145      xs is the first local node number, x is the number of local nodes
146   */
147   if (!lx) {
148     ierr = PetscMalloc1(m, &dd->lx);CHKERRQ(ierr);
149     ierr = PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_blockcomm",&flg1,NULL);CHKERRQ(ierr);
150     ierr = PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_nodes_at_end",&flg2,NULL);CHKERRQ(ierr);
151     if (flg1) {      /* Block Comm type Distribution */
152       xs = rank*M/m;
153       x  = (rank + 1)*M/m - xs;
154     } else if (flg2) { /* The odd nodes are evenly distributed across last nodes */
155       x = (M + rank)/m;
156       if (M/m == x) xs = rank*x;
157       else          xs = rank*(x-1) + (M+rank)%(x*m);
158     } else { /* The odd nodes are evenly distributed across the first k nodes */
159       /* Regular PETSc Distribution */
160       x = M/m + ((M % m) > rank);
161       if (rank >= (M % m)) xs = (rank * (PetscInt)(M/m) + M % m);
162       else                 xs = rank * (PetscInt)(M/m) + rank;
163     }
164     ierr = MPI_Allgather(&xs,1,MPIU_INT,dd->lx,1,MPIU_INT,comm);CHKERRQ(ierr);
165     for (i=0; i<m-1; i++) dd->lx[i] = dd->lx[i+1] - dd->lx[i];
166     dd->lx[m-1] = M - dd->lx[m-1];
167   } else {
168     x  = lx[rank];
169     xs = 0;
170     for (i=0; i<rank; i++) xs += lx[i];
171     /* verify that data user provided is consistent */
172     left = xs;
173     for (i=rank; i<size; i++) left += lx[i];
174     if (left != M) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Sum of lx across processors not equal to M %D %D",left,M);
175   }
176 
177   /*
178    check if the scatter requires more than one process neighbor or wraps around
179    the domain more than once
180   */
181   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);
182 
183   xe  = xs + x;
184 
185   /* determine ghost region (Xs) and region scattered into (IXs)  */
186   if (xs-sDist > 0) {
187     Xs  = xs - sDist;
188     IXs = xs - sDist;
189   } else {
190     if (bx) Xs = xs - sDist;
191     else Xs = 0;
192     IXs = 0;
193   }
194   if (xe+sDist <= M) {
195     Xe  = xe + sDist;
196     IXe = xe + sDist;
197   } else {
198     if (bx) Xe = xe + sDist;
199     else Xe = M;
200     IXe = M;
201   }
202 
203   if (bx == DM_BOUNDARY_PERIODIC || bx == DM_BOUNDARY_MIRROR) {
204     Xs  = xs - sDist;
205     Xe  = xe + sDist;
206     IXs = xs - sDist;
207     IXe = xe + sDist;
208   }
209 
210   /* allocate the base parallel and sequential vectors */
211   dd->Nlocal = dof*x;
212   ierr       = VecCreateMPIWithArray(comm,dof,dd->Nlocal,PETSC_DECIDE,NULL,&global);CHKERRQ(ierr);
213   dd->nlocal = dof*(Xe-Xs);
214   ierr       = VecCreateSeqWithArray(PETSC_COMM_SELF,dof,dd->nlocal,NULL,&local);CHKERRQ(ierr);
215 
216   ierr = VecGetOwnershipRange(global,&start,NULL);CHKERRQ(ierr);
217 
218   /* Create Global to Local Vector Scatter Context */
219   /* global to local must retrieve ghost points */
220   ierr = ISCreateStride(comm,dof*(IXe-IXs),dof*(IXs-Xs),1,&to);CHKERRQ(ierr);
221 
222   ierr = PetscMalloc1(x+2*sDist,&idx);CHKERRQ(ierr);
223   ierr = PetscLogObjectMemory((PetscObject)da,(x+2*(sDist))*sizeof(PetscInt));CHKERRQ(ierr);
224 
225   for (i=0; i<IXs-Xs; i++) idx[i] = -1; /* prepend with -1s if needed for ghosted case*/
226 
227   nn = IXs-Xs;
228   if (bx == DM_BOUNDARY_PERIODIC) { /* Handle all cases with periodic first */
229     for (i=0; i<sDist; i++) {  /* Left ghost points */
230       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
231       else                 idx[nn++] = M+(xs-sDist+i);
232     }
233 
234     for (i=0; i<x; i++) idx [nn++] = xs + i;  /* Non-ghost points */
235 
236     for (i=0; i<sDist; i++) { /* Right ghost points */
237       if ((xe+i)<M) idx [nn++] =  xe+i;
238       else          idx [nn++] = (xe+i) - M;
239     }
240   } else if (bx == DM_BOUNDARY_MIRROR) { /* Handle all cases with periodic first */
241     for (i=0; i<(sDist); i++) {  /* Left ghost points */
242       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
243       else                 idx[nn++] = sDist - i;
244     }
245 
246     for (i=0; i<x; i++) idx [nn++] = xs + i;  /* Non-ghost points */
247 
248     for (i=0; i<(sDist); i++) { /* Right ghost points */
249       if ((xe+i)<M) idx[nn++] =  xe+i;
250       else          idx[nn++] = M - (i + 1);
251     }
252   } else {      /* Now do all cases with no periodicity */
253     if (0 <= xs-sDist) {
254       for (i=0; i<sDist; i++) idx[nn++] = xs - sDist + i;
255     } else {
256       for (i=0; i<xs; i++) idx[nn++] = i;
257     }
258 
259     for (i=0; i<x; i++) idx [nn++] = xs + i;
260 
261     if ((xe+sDist)<=M) {
262       for (i=0; i<sDist; i++) idx[nn++]=xe+i;
263     } else {
264       for (i=xe; i<M; i++) idx[nn++]=i;
265     }
266   }
267 
268   ierr = ISCreateBlock(comm,dof,nn-IXs+Xs,&idx[IXs-Xs],PETSC_USE_POINTER,&from);CHKERRQ(ierr);
269   ierr = VecScatterCreate(global,from,local,to,&gtol);CHKERRQ(ierr);
270   ierr = PetscLogObjectParent((PetscObject)da,(PetscObject)gtol);CHKERRQ(ierr);
271   ierr = ISDestroy(&to);CHKERRQ(ierr);
272   ierr = ISDestroy(&from);CHKERRQ(ierr);
273   ierr = VecDestroy(&local);CHKERRQ(ierr);
274   ierr = VecDestroy(&global);CHKERRQ(ierr);
275 
276   dd->xs = dof*xs; dd->xe = dof*xe; dd->ys = 0; dd->ye = 1; dd->zs = 0; dd->ze = 1;
277   dd->Xs = dof*Xs; dd->Xe = dof*Xe; dd->Ys = 0; dd->Ye = 1; dd->Zs = 0; dd->Ze = 1;
278 
279   dd->gtol      = gtol;
280   dd->base      = dof*xs;
281   da->ops->view = DMView_DA_1d;
282 
283   /*
284      Set the local to global ordering in the global vector, this allows use
285      of VecSetValuesLocal().
286   */
287   for (i=0; i<Xe-IXe; i++) idx[nn++] = -1; /* pad with -1s if needed for ghosted case*/
288 
289   ierr = ISLocalToGlobalMappingCreate(comm,dof,nn,idx,PETSC_OWN_POINTER,&da->ltogmap);CHKERRQ(ierr);
290   ierr = PetscLogObjectParent((PetscObject)da,(PetscObject)da->ltogmap);CHKERRQ(ierr);
291 
292   PetscFunctionReturn(0);
293 }
294 
295 
296 #undef __FUNCT__
297 #define __FUNCT__ "DMDACreate1d"
298 /*@C
299    DMDACreate1d - Creates an object that will manage the communication of  one-dimensional
300    regular array data that is distributed across some processors.
301 
302    Collective on MPI_Comm
303 
304    Input Parameters:
305 +  comm - MPI communicator
306 .  bx - type of ghost cells at the boundary the array should have, if any. Use
307           DM_BOUNDARY_NONE, DM_BOUNDARY_GHOSTED, or DM_BOUNDARY_PERIODIC.
308 .  M - global dimension of the array (use -M to indicate that it may be set to a different value
309             from the command line with -da_grid_x <M>)
310 .  dof - number of degrees of freedom per node
311 .  s - stencil width
312 -  lx - array containing number of nodes in the X direction on each processor,
313         or NULL. If non-null, must be of length as the number of processes in the MPI_Comm.
314 
315    Output Parameter:
316 .  da - the resulting distributed array object
317 
318    Options Database Key:
319 +  -dm_view - Calls DMView() at the conclusion of DMDACreate1d()
320 .  -da_grid_x <nx> - number of grid points in x direction; can set if M < 0
321 .  -da_refine_x <rx> - refinement factor
322 -  -da_refine <n> - refine the DMDA n times before creating it, if M < 0
323 
324    Level: beginner
325 
326    Notes:
327    The array data itself is NOT stored in the DMDA, it is stored in Vec objects;
328    The appropriate vector objects can be obtained with calls to DMCreateGlobalVector()
329    and DMCreateLocalVector() and calls to VecDuplicate() if more are needed.
330 
331 .keywords: distributed array, create, one-dimensional
332 
333 .seealso: DMDestroy(), DMView(), DMDACreate2d(), DMDACreate3d(), DMGlobalToLocalBegin(), DMDASetRefinementFactor(),
334           DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMLocalToLocalBegin(), DMLocalToLocalEnd(), DMDAGetRefinementFactor(),
335           DMDAGetInfo(), DMCreateGlobalVector(), DMCreateLocalVector(), DMDACreateNaturalVector(), DMLoad(), DMDAGetOwnershipRanges()
336 
337 @*/
338 PetscErrorCode  DMDACreate1d(MPI_Comm comm, DMBoundaryType bx, PetscInt M, PetscInt dof, PetscInt s, const PetscInt lx[], DM *da)
339 {
340   PetscErrorCode ierr;
341   PetscMPIInt    size;
342 
343   PetscFunctionBegin;
344   ierr = DMDACreate(comm, da);CHKERRQ(ierr);
345   ierr = DMSetDimension(*da, 1);CHKERRQ(ierr);
346   ierr = DMDASetSizes(*da, M, 1, 1);CHKERRQ(ierr);
347   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
348   ierr = DMDASetNumProcs(*da, size, PETSC_DECIDE, PETSC_DECIDE);CHKERRQ(ierr);
349   ierr = DMDASetBoundaryType(*da, bx, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE);CHKERRQ(ierr);
350   ierr = DMDASetDof(*da, dof);CHKERRQ(ierr);
351   ierr = DMDASetStencilWidth(*da, s);CHKERRQ(ierr);
352   ierr = DMDASetOwnershipRanges(*da, lx, NULL, NULL);CHKERRQ(ierr);
353   /* This violates the behavior for other classes, but right now users expect negative dimensions to be handled this way */
354   ierr = DMSetFromOptions(*da);CHKERRQ(ierr);
355   ierr = DMSetUp(*da);CHKERRQ(ierr);
356   PetscFunctionReturn(0);
357 }
358