Actual source code: da1.c
petsc-3.10.5 2019-03-28
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      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: {
     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

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

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

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

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

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

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

     97:     PetscDrawCollectiveBegin(draw);
     98:     /* draw my box */
     99:     ymin = 0; ymax = 0.3; xmin = dd->xs / dd->w; xmax = (dd->xe / dd->w)  - 1;
    100:     PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_RED);
    101:     PetscDrawLine(draw,xmin,ymin,xmin,ymax,PETSC_DRAW_RED);
    102:     PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_RED);
    103:     PetscDrawLine(draw,xmax,ymin,xmax,ymax,PETSC_DRAW_RED);
    104:     /* Put in index numbers */
    105:     base = dd->base / dd->w;
    106:     for (x=xmin; x<=xmax; x++) {
    107:       PetscSNPrintf(node,sizeof(node),"%d",(int)base++);
    108:       PetscDrawString(draw,x,ymin,PETSC_DRAW_RED,node);
    109:     }
    110:     PetscDrawCollectiveEnd(draw);
    111:     PetscDrawFlush(draw);
    112:     PetscDrawPause(draw);
    113:     PetscDrawSave(draw);
    114:   } else if (isglvis) {
    115:     DMView_DA_GLVis(da,viewer);
    116:   } else if (isbinary) {
    117:     DMView_DA_Binary(da,viewer);
    118: #if defined(PETSC_HAVE_MATLAB_ENGINE)
    119:   } else if (ismatlab) {
    120:     DMView_DA_Matlab(da,viewer);
    121: #endif
    122:   }
    123:   return(0);
    124: }

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

    146:   PetscObjectGetComm((PetscObject) da, &comm);
    147:   MPI_Comm_size(comm,&size);
    148:   MPI_Comm_rank(comm,&rank);

    150:   dd->p = 1;
    151:   dd->n = 1;
    152:   dd->m = size;
    153:   m     = dd->m;

    155:   if (s > 0) {
    156:     /* if not communicating data then should be ok to have nothing on some processes */
    157:     if (M < m) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"More processes than data points! %D %D",m,M);
    158:     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);
    159:   }

    161:   /*
    162:      Determine locally owned region
    163:      xs is the first local node number, x is the number of local nodes
    164:   */
    165:   if (!lx) {
    166:     PetscMalloc1(m, &dd->lx);
    167:     PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_blockcomm",&flg1,NULL);
    168:     PetscOptionsGetBool(((PetscObject)da)->options,((PetscObject)da)->prefix,"-da_partition_nodes_at_end",&flg2,NULL);
    169:     if (flg1) {      /* Block Comm type Distribution */
    170:       xs = rank*M/m;
    171:       x  = (rank + 1)*M/m - xs;
    172:     } else if (flg2) { /* The odd nodes are evenly distributed across last nodes */
    173:       x = (M + rank)/m;
    174:       if (M/m == x) xs = rank*x;
    175:       else          xs = rank*(x-1) + (M+rank)%(x*m);
    176:     } else { /* The odd nodes are evenly distributed across the first k nodes */
    177:       /* Regular PETSc Distribution */
    178:       x = M/m + ((M % m) > rank);
    179:       if (rank >= (M % m)) xs = (rank * (PetscInt)(M/m) + M % m);
    180:       else                 xs = rank * (PetscInt)(M/m) + rank;
    181:     }
    182:     MPI_Allgather(&xs,1,MPIU_INT,dd->lx,1,MPIU_INT,comm);
    183:     for (i=0; i<m-1; i++) dd->lx[i] = dd->lx[i+1] - dd->lx[i];
    184:     dd->lx[m-1] = M - dd->lx[m-1];
    185:   } else {
    186:     x  = lx[rank];
    187:     xs = 0;
    188:     for (i=0; i<rank; i++) xs += lx[i];
    189:     /* verify that data user provided is consistent */
    190:     left = xs;
    191:     for (i=rank; i<size; i++) left += lx[i];
    192:     if (left != M) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Sum of lx across processors not equal to M %D %D",left,M);
    193:   }

    195:   /*
    196:    check if the scatter requires more than one process neighbor or wraps around
    197:    the domain more than once
    198:   */
    199:   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);

    201:   xe  = xs + x;

    203:   /* determine ghost region (Xs) and region scattered into (IXs)  */
    204:   if (xs-sDist > 0) {
    205:     Xs  = xs - sDist;
    206:     IXs = xs - sDist;
    207:   } else {
    208:     if (bx) Xs = xs - sDist;
    209:     else Xs = 0;
    210:     IXs = 0;
    211:   }
    212:   if (xe+sDist <= M) {
    213:     Xe  = xe + sDist;
    214:     IXe = xe + sDist;
    215:   } else {
    216:     if (bx) Xe = xe + sDist;
    217:     else Xe = M;
    218:     IXe = M;
    219:   }

    221:   if (bx == DM_BOUNDARY_PERIODIC || bx == DM_BOUNDARY_MIRROR) {
    222:     Xs  = xs - sDist;
    223:     Xe  = xe + sDist;
    224:     IXs = xs - sDist;
    225:     IXe = xe + sDist;
    226:   }

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

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

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

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

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

    245:   nn = IXs-Xs;
    246:   if (bx == DM_BOUNDARY_PERIODIC) { /* Handle all cases with periodic first */
    247:     for (i=0; i<sDist; i++) {  /* Left ghost points */
    248:       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
    249:       else                 idx[nn++] = M+(xs-sDist+i);
    250:     }

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

    254:     for (i=0; i<sDist; i++) { /* Right ghost points */
    255:       if ((xe+i)<M) idx [nn++] =  xe+i;
    256:       else          idx [nn++] = (xe+i) - M;
    257:     }
    258:   } else if (bx == DM_BOUNDARY_MIRROR) { /* Handle all cases with periodic first */
    259:     for (i=0; i<(sDist); i++) {  /* Left ghost points */
    260:       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
    261:       else                 idx[nn++] = sDist - i;
    262:     }

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

    266:     for (i=0; i<(sDist); i++) { /* Right ghost points */
    267:       if ((xe+i)<M) idx[nn++] =  xe+i;
    268:       else          idx[nn++] = M - (i + 2);
    269:     }
    270:   } else {      /* Now do all cases with no periodicity */
    271:     if (0 <= xs-sDist) {
    272:       for (i=0; i<sDist; i++) idx[nn++] = xs - sDist + i;
    273:     } else {
    274:       for (i=0; i<xs; i++) idx[nn++] = i;
    275:     }

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

    279:     if ((xe+sDist)<=M) {
    280:       for (i=0; i<sDist; i++) idx[nn++]=xe+i;
    281:     } else {
    282:       for (i=xe; i<M; i++) idx[nn++]=i;
    283:     }
    284:   }

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

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

    297:   dd->gtol      = gtol;
    298:   dd->base      = dof*xs;
    299:   da->ops->view = DMView_DA_1d;

    301:   /*
    302:      Set the local to global ordering in the global vector, this allows use
    303:      of VecSetValuesLocal().
    304:   */
    305:   for (i=0; i<Xe-IXe; i++) idx[nn++] = -1; /* pad with -1s if needed for ghosted case*/

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

    310:   return(0);
    311: }

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

    318:    Collective on MPI_Comm

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

    332:    Output Parameter:
    333: .  da - the resulting distributed array object

    335:    Options Database Key:
    336: +  -dm_view - Calls DMView() at the conclusion of DMDACreate1d()
    337: .  -da_grid_x <nx> - number of grid points in x direction
    338: .  -da_refine_x <rx> - refinement factor
    339: -  -da_refine <n> - refine the DMDA n times before creating it

    341:    Level: beginner

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

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

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

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

    355: .seealso: DMDestroy(), DMView(), DMDACreate2d(), DMDACreate3d(), DMGlobalToLocalBegin(), DMDASetRefinementFactor(),
    356:           DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMLocalToLocalBegin(), DMLocalToLocalEnd(), DMDAGetRefinementFactor(),
    357:           DMDAGetInfo(), DMCreateGlobalVector(), DMCreateLocalVector(), DMDACreateNaturalVector(), DMLoad(), DMDAGetOwnershipRanges()

    359: @*/
    360: PetscErrorCode  DMDACreate1d(MPI_Comm comm, DMBoundaryType bx, PetscInt M, PetscInt dof, PetscInt s, const PetscInt lx[], DM *da)
    361: {
    363:   PetscMPIInt    size;

    366:   DMDACreate(comm, da);
    367:   DMSetDimension(*da, 1);
    368:   DMDASetSizes(*da, M, 1, 1);
    369:   MPI_Comm_size(comm, &size);
    370:   DMDASetNumProcs(*da, size, PETSC_DECIDE, PETSC_DECIDE);
    371:   DMDASetBoundaryType(*da, bx, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE);
    372:   DMDASetDof(*da, dof);
    373:   DMDASetStencilWidth(*da, s);
    374:   DMDASetOwnershipRanges(*da, lx, NULL, NULL);
    375:   return(0);
    376: }