Actual source code: da1.c

      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: {
     12:   PetscMPIInt    rank;
     13:   PetscBool      iascii,isdraw,isglvis,isbinary;
     14:   DM_DA          *dd = (DM_DA*)da->data;
     15: #if defined(PETSC_HAVE_MATLAB_ENGINE)
     16:   PetscBool ismatlab;
     17: #endif

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

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

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

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

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

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

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

    125: PetscErrorCode  DMSetUp_DA_1D(DM da)
    126: {
    127:   DM_DA            *dd   = (DM_DA*)da->data;
    128:   const PetscInt   M     = dd->M;
    129:   const PetscInt   dof   = dd->w;
    130:   const PetscInt   s     = dd->s;
    131:   const PetscInt   sDist = s;  /* stencil distance in points */
    132:   const PetscInt   *lx   = dd->lx;
    133:   DMBoundaryType   bx    = dd->bx;
    134:   MPI_Comm         comm;
    135:   Vec              local, global;
    136:   VecScatter       gtol;
    137:   IS               to, from;
    138:   PetscBool        flg1 = PETSC_FALSE, flg2 = PETSC_FALSE;
    139:   PetscMPIInt      rank, size;
    140:   PetscInt         i,*idx,nn,left,xs,xe,x,Xs,Xe,start,m,IXs,IXe;

    142:   PetscObjectGetComm((PetscObject) da, &comm);
    143:   MPI_Comm_size(comm,&size);
    144:   MPI_Comm_rank(comm,&rank);

    146:   dd->p = 1;
    147:   dd->n = 1;
    148:   dd->m = size;
    149:   m     = dd->m;

    151:   if (s > 0) {
    152:     /* if not communicating data then should be ok to have nothing on some processes */
    155:   }

    157:   /*
    158:      Determine locally owned region
    159:      xs is the first local node number, x is the number of local nodes
    160:   */
    161:   if (!lx) {
    162:     PetscMalloc1(m, &dd->lx);
    163:     PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_blockcomm",&flg1,NULL);
    164:     PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_nodes_at_end",&flg2,NULL);
    165:     if (flg1) {      /* Block Comm type Distribution */
    166:       xs = rank*M/m;
    167:       x  = (rank + 1)*M/m - xs;
    168:     } else if (flg2) { /* The odd nodes are evenly distributed across last nodes */
    169:       x = (M + rank)/m;
    170:       if (M/m == x) xs = rank*x;
    171:       else          xs = rank*(x-1) + (M+rank)%(x*m);
    172:     } else { /* The odd nodes are evenly distributed across the first k nodes */
    173:       /* Regular PETSc Distribution */
    174:       x = M/m + ((M % m) > rank);
    175:       if (rank >= (M % m)) xs = (rank * (PetscInt)(M/m) + M % m);
    176:       else                 xs = rank * (PetscInt)(M/m) + rank;
    177:     }
    178:     MPI_Allgather(&xs,1,MPIU_INT,dd->lx,1,MPIU_INT,comm);
    179:     for (i=0; i<m-1; i++) dd->lx[i] = dd->lx[i+1] - dd->lx[i];
    180:     dd->lx[m-1] = M - dd->lx[m-1];
    181:   } else {
    182:     x  = lx[rank];
    183:     xs = 0;
    184:     for (i=0; i<rank; i++) xs += lx[i];
    185:     /* verify that data user provided is consistent */
    186:     left = xs;
    187:     for (i=rank; i<size; i++) left += lx[i];
    189:   }

    191:   /*
    192:    check if the scatter requires more than one process neighbor or wraps around
    193:    the domain more than once
    194:   */

    197:   xe  = xs + x;

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

    217:   if (bx == DM_BOUNDARY_PERIODIC || bx == DM_BOUNDARY_MIRROR) {
    218:     Xs  = xs - sDist;
    219:     Xe  = xe + sDist;
    220:     IXs = xs - sDist;
    221:     IXe = xe + sDist;
    222:   }

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

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

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

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

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

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

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

    250:     for (i=0; i<sDist; i++) { /* Right ghost points */
    251:       if ((xe+i)<M) idx [nn++] =  xe+i;
    252:       else          idx [nn++] = (xe+i) - M;
    253:     }
    254:   } else if (bx == DM_BOUNDARY_MIRROR) { /* Handle all cases with periodic first */
    255:     for (i=0; i<(sDist); i++) {  /* Left ghost points */
    256:       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
    257:       else                 idx[nn++] = sDist - i;
    258:     }

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

    262:     for (i=0; i<(sDist); i++) { /* Right ghost points */
    263:       if ((xe+i)<M) idx[nn++] =  xe+i;
    264:       else          idx[nn++] = M - (i + 2);
    265:     }
    266:   } else {      /* Now do all cases with no periodicity */
    267:     if (0 <= xs-sDist) {
    268:       for (i=0; i<sDist; i++) idx[nn++] = xs - sDist + i;
    269:     } else {
    270:       for (i=0; i<xs; i++) idx[nn++] = i;
    271:     }

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

    275:     if ((xe+sDist)<=M) {
    276:       for (i=0; i<sDist; i++) idx[nn++]=xe+i;
    277:     } else {
    278:       for (i=xe; i<M; i++) idx[nn++]=i;
    279:     }
    280:   }

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

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

    293:   dd->gtol      = gtol;
    294:   dd->base      = dof*xs;
    295:   da->ops->view = DMView_DA_1d;

    297:   /*
    298:      Set the local to global ordering in the global vector, this allows use
    299:      of VecSetValuesLocal().
    300:   */
    301:   for (i=0; i<Xe-IXe; i++) idx[nn++] = -1; /* pad with -1s if needed for ghosted case*/

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

    306:   return 0;
    307: }

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

    313:    Collective

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

    327:    Output Parameter:
    328: .  da - the resulting distributed array object

    330:    Options Database Key:
    331: +  -dm_view - Calls DMView() at the conclusion of DMDACreate1d()
    332: .  -da_grid_x <nx> - number of grid points in x direction
    333: .  -da_refine_x <rx> - refinement factor
    334: -  -da_refine <n> - refine the DMDA n times before creating it

    336:    Level: beginner

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

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

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

    348: .seealso: DMDestroy(), DMView(), DMDACreate2d(), DMDACreate3d(), DMGlobalToLocalBegin(), DMDASetRefinementFactor(),
    349:           DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMLocalToLocalBegin(), DMLocalToLocalEnd(), DMDAGetRefinementFactor(),
    350:           DMDAGetInfo(), DMCreateGlobalVector(), DMCreateLocalVector(), DMDACreateNaturalVector(), DMLoad(), DMDAGetOwnershipRanges(),
    351:           DMStagCreate1d()

    353: @*/
    354: PetscErrorCode  DMDACreate1d(MPI_Comm comm, DMBoundaryType bx, PetscInt M, PetscInt dof, PetscInt s, const PetscInt lx[], DM *da)
    355: {
    356:   PetscMPIInt    size;

    358:   DMDACreate(comm, da);
    359:   DMSetDimension(*da, 1);
    360:   DMDASetSizes(*da, M, 1, 1);
    361:   MPI_Comm_size(comm, &size);
    362:   DMDASetNumProcs(*da, size, PETSC_DECIDE, PETSC_DECIDE);
    363:   DMDASetBoundaryType(*da, bx, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE);
    364:   DMDASetDof(*da, dof);
    365:   DMDASetStencilWidth(*da, s);
    366:   DMDASetOwnershipRanges(*da, lx, NULL, NULL);
    367:   return 0;
    368: }