xref: /petsc/src/dm/impls/da/da1.c (revision 1ebf93c6b7d760d592de6ebe6cdc0debaa3caf75)
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 static 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     ierr = PetscDrawSetCoordinates(draw,xmin,ymin,xmax,ymax);CHKERRQ(ierr);
60 
61     ierr = PetscDrawCollectiveBegin(draw);CHKERRQ(ierr);
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         ierr = PetscDrawLine(draw,(double)xmin_tmp,ymin,(double)xmin_tmp,ymax,PETSC_DRAW_BLACK);CHKERRQ(ierr);
68       }
69       xmin = 0.0; xmax = dd->M - 1;
70       ierr = PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_BLACK);CHKERRQ(ierr);
71       ierr = PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_BLACK);CHKERRQ(ierr);
72     }
73     ierr = PetscDrawCollectiveEnd(draw);CHKERRQ(ierr);
74     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
75     ierr = PetscDrawPause(draw);CHKERRQ(ierr);
76 
77     ierr = PetscDrawCollectiveBegin(draw);CHKERRQ(ierr);
78     /* draw my box */
79     ymin = 0; ymax = 0.3; xmin = dd->xs / dd->w; xmax = (dd->xe / dd->w)  - 1;
80     ierr = PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_RED);CHKERRQ(ierr);
81     ierr = PetscDrawLine(draw,xmin,ymin,xmin,ymax,PETSC_DRAW_RED);CHKERRQ(ierr);
82     ierr = PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_RED);CHKERRQ(ierr);
83     ierr = PetscDrawLine(draw,xmax,ymin,xmax,ymax,PETSC_DRAW_RED);CHKERRQ(ierr);
84     /* Put in index numbers */
85     base = dd->base / dd->w;
86     for (x=xmin; x<=xmax; x++) {
87       ierr = PetscSNPrintf(node,sizeof(node),"%d",(int)base++);CHKERRQ(ierr);
88       ierr = PetscDrawString(draw,x,ymin,PETSC_DRAW_RED,node);CHKERRQ(ierr);
89     }
90     ierr = PetscDrawCollectiveEnd(draw);CHKERRQ(ierr);
91     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
92     ierr = PetscDrawPause(draw);CHKERRQ(ierr);
93     ierr = PetscDrawSave(draw);CHKERRQ(ierr);
94   } else if (isbinary) {
95     ierr = DMView_DA_Binary(da,viewer);CHKERRQ(ierr);
96 #if defined(PETSC_HAVE_MATLAB_ENGINE)
97   } else if (ismatlab) {
98     ierr = DMView_DA_Matlab(da,viewer);CHKERRQ(ierr);
99 #endif
100   }
101   PetscFunctionReturn(0);
102 }
103 
104 
105 #undef __FUNCT__
106 #define __FUNCT__ "DMSetUp_DA_1D"
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;
124 
125   PetscFunctionBegin;
126   ierr = PetscObjectGetComm((PetscObject) da, &comm);CHKERRQ(ierr);
127   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
128   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
129 
130   dd->p = 1;
131   dd->n = 1;
132   dd->m = size;
133   m     = dd->m;
134 
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   }
140 
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     ierr = PetscMalloc1(m, &dd->lx);CHKERRQ(ierr);
147     ierr = PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_blockcomm",&flg1,NULL);CHKERRQ(ierr);
148     ierr = PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_nodes_at_end",&flg2,NULL);CHKERRQ(ierr);
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     ierr = MPI_Allgather(&xs,1,MPIU_INT,dd->lx,1,MPIU_INT,comm);CHKERRQ(ierr);
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   }
174 
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);
180 
181   xe  = xs + x;
182 
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   }
200 
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   }
207 
208   /* allocate the base parallel and sequential vectors */
209   dd->Nlocal = dof*x;
210   ierr       = VecCreateMPIWithArray(comm,dof,dd->Nlocal,PETSC_DECIDE,NULL,&global);CHKERRQ(ierr);
211   dd->nlocal = dof*(Xe-Xs);
212   ierr       = VecCreateSeqWithArray(PETSC_COMM_SELF,dof,dd->nlocal,NULL,&local);CHKERRQ(ierr);
213 
214   ierr = VecGetOwnershipRange(global,&start,NULL);CHKERRQ(ierr);
215 
216   /* Create Global to Local Vector Scatter Context */
217   /* global to local must retrieve ghost points */
218   ierr = ISCreateStride(comm,dof*(IXe-IXs),dof*(IXs-Xs),1,&to);CHKERRQ(ierr);
219 
220   ierr = PetscMalloc1(x+2*sDist,&idx);CHKERRQ(ierr);
221   ierr = PetscLogObjectMemory((PetscObject)da,(x+2*(sDist))*sizeof(PetscInt));CHKERRQ(ierr);
222 
223   for (i=0; i<IXs-Xs; i++) idx[i] = -1; /* prepend with -1s if needed for ghosted case*/
224 
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     }
231 
232     for (i=0; i<x; i++) idx [nn++] = xs + i;  /* Non-ghost points */
233 
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     }
243 
244     for (i=0; i<x; i++) idx [nn++] = xs + i;  /* Non-ghost points */
245 
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     }
256 
257     for (i=0; i<x; i++) idx [nn++] = xs + i;
258 
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   }
265 
266   ierr = ISCreateBlock(comm,dof,nn-IXs+Xs,&idx[IXs-Xs],PETSC_USE_POINTER,&from);CHKERRQ(ierr);
267   ierr = VecScatterCreate(global,from,local,to,&gtol);CHKERRQ(ierr);
268   ierr = PetscLogObjectParent((PetscObject)da,(PetscObject)gtol);CHKERRQ(ierr);
269   ierr = ISDestroy(&to);CHKERRQ(ierr);
270   ierr = ISDestroy(&from);CHKERRQ(ierr);
271   ierr = VecDestroy(&local);CHKERRQ(ierr);
272   ierr = VecDestroy(&global);CHKERRQ(ierr);
273 
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;
276 
277   dd->gtol      = gtol;
278   dd->base      = dof*xs;
279   da->ops->view = DMView_DA_1d;
280 
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*/
286 
287   ierr = ISLocalToGlobalMappingCreate(comm,dof,nn,idx,PETSC_OWN_POINTER,&da->ltogmap);CHKERRQ(ierr);
288   ierr = PetscLogObjectParent((PetscObject)da,(PetscObject)da->ltogmap);CHKERRQ(ierr);
289 
290   PetscFunctionReturn(0);
291 }
292 
293 
294 #undef __FUNCT__
295 #define __FUNCT__ "DMDACreate1d"
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.
299 
300    Collective on MPI_Comm
301 
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.
312 
313    Output Parameter:
314 .  da - the resulting distributed array object
315 
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
321 
322    Level: beginner
323 
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.
328 
329 .keywords: distributed array, create, one-dimensional
330 
331 .seealso: DMDestroy(), DMView(), DMDACreate2d(), DMDACreate3d(), DMGlobalToLocalBegin(), DMDASetRefinementFactor(),
332           DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMLocalToLocalBegin(), DMLocalToLocalEnd(), DMDAGetRefinementFactor(),
333           DMDAGetInfo(), DMCreateGlobalVector(), DMCreateLocalVector(), DMDACreateNaturalVector(), DMLoad(), DMDAGetOwnershipRanges()
334 
335 @*/
336 PetscErrorCode  DMDACreate1d(MPI_Comm comm, DMBoundaryType bx, PetscInt M, PetscInt dof, PetscInt s, const PetscInt lx[], DM *da)
337 {
338   PetscErrorCode ierr;
339   PetscMPIInt    size;
340 
341   PetscFunctionBegin;
342   ierr = DMDACreate(comm, da);CHKERRQ(ierr);
343   ierr = DMSetDimension(*da, 1);CHKERRQ(ierr);
344   ierr = DMDASetSizes(*da, M, 1, 1);CHKERRQ(ierr);
345   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
346   ierr = DMDASetNumProcs(*da, size, PETSC_DECIDE, PETSC_DECIDE);CHKERRQ(ierr);
347   ierr = DMDASetBoundaryType(*da, bx, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE);CHKERRQ(ierr);
348   ierr = DMDASetDof(*da, dof);CHKERRQ(ierr);
349   ierr = DMDASetStencilWidth(*da, s);CHKERRQ(ierr);
350   ierr = DMDASetOwnershipRanges(*da, lx, NULL, NULL);CHKERRQ(ierr);
351   /* This violates the behavior for other classes, but right now users expect negative dimensions to be handled this way */
352   ierr = DMSetFromOptions(*da);CHKERRQ(ierr);
353   ierr = DMSetUp(*da);CHKERRQ(ierr);
354   PetscFunctionReturn(0);
355 }
356