Date: 2015-10-02T22:13:01+00:00

Actual source code: da1.c
petsc-3.6.2 2015-10-02
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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>     /*I  "petscdmda.h"   I*/

      9: #include <petscdraw.h>
     12: PetscErrorCode DMView_DA_1d(DM da,PetscViewer viewer)
     13: {
     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

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

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

     34:     PetscViewerGetFormat(viewer, &format);
     35:     if (format != PETSC_VIEWER_ASCII_VTK && format != PETSC_VIEWER_ASCII_VTK_CELL) {
     36:       DMDALocalInfo info;
     37:       DMDAGetLocalInfo(da,&info);
     38:       PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);
     39:       PetscViewerASCIISynchronizedPrintf(viewer,"Processor [%d] M %D m %D w %D s %D\n",rank,dd->M,dd->m,dd->w,dd->s);
     40:       PetscViewerASCIISynchronizedPrintf(viewer,"X range of indices: %D %D\n",info.xs,info.xs+info.xm);
     41:       PetscViewerFlush(viewer);
     42:       PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);
     43:     } else {
     44:       DMView_DA_VTK(da, viewer);
     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;

     53:     PetscViewerDrawGetDraw(viewer,0,&draw);
     54:     PetscDrawIsNull(draw,&isnull); if (isnull) return(0);

     56:     PetscDrawSetCoordinates(draw,xmin,ymin,xmax,ymax);
     57:     PetscDrawSynchronizedClear(draw);

     59:     /* first processor draws all node lines */
     60:     if (!rank) {
     61:       PetscInt xmin_tmp;
     62:       ymin = 0.0; ymax = 0.3;

     64:       for (xmin_tmp=0; xmin_tmp < dd->M; xmin_tmp++) {
     65:         PetscDrawLine(draw,(double)xmin_tmp,ymin,(double)xmin_tmp,ymax,PETSC_DRAW_BLACK);
     66:       }

     68:       xmin = 0.0; xmax = dd->M - 1;
     69:       PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_BLACK);
     70:       PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_BLACK);
     71:     }

     73:     PetscDrawSynchronizedFlush(draw);
     74:     PetscDrawPause(draw);

     76:     /* draw my box */
     77:     ymin = 0; ymax = 0.3; xmin = dd->xs / dd->w; xmax = (dd->xe / dd->w)  - 1;
     78:     PetscDrawLine(draw,xmin,ymin,xmax,ymin,PETSC_DRAW_RED);
     79:     PetscDrawLine(draw,xmin,ymin,xmin,ymax,PETSC_DRAW_RED);
     80:     PetscDrawLine(draw,xmin,ymax,xmax,ymax,PETSC_DRAW_RED);
     81:     PetscDrawLine(draw,xmax,ymin,xmax,ymax,PETSC_DRAW_RED);

     83:     /* Put in index numbers */
     84:     base = dd->base / dd->w;
     85:     for (x=xmin; x<=xmax; x++) {
     86:       sprintf(node,"%d",(int)base++);
     87:       PetscDrawString(draw,x,ymin,PETSC_DRAW_RED,node);
     88:     }

     90:     PetscDrawSynchronizedFlush(draw);
     91:     PetscDrawPause(draw);
     92:   } else if (isbinary) {
     93:     DMView_DA_Binary(da,viewer);
     94: #if defined(PETSC_HAVE_MATLAB_ENGINE)
     95:   } else if (ismatlab) {
     96:     DMView_DA_Matlab(da,viewer);
     97: #endif
     98:   }
     99:   return(0);
    100: }

    105: PetscErrorCode  DMSetUp_DA_1D(DM da)
    106: {
    107:   DM_DA            *dd   = (DM_DA*)da->data;
    108:   const PetscInt   M     = dd->M;
    109:   const PetscInt   dof   = dd->w;
    110:   const PetscInt   s     = dd->s;
    111:   const PetscInt   sDist = s;  /* stencil distance in points */
    112:   const PetscInt   *lx   = dd->lx;
    113:   DMBoundaryType   bx    = dd->bx;
    114:   MPI_Comm         comm;
    115:   Vec              local, global;
    116:   VecScatter       gtol;
    117:   IS               to, from;
    118:   PetscBool        flg1 = PETSC_FALSE, flg2 = PETSC_FALSE;
    119:   PetscMPIInt      rank, size;
    120:   PetscInt         i,*idx,nn,left,xs,xe,x,Xs,Xe,start,m,IXs,IXe;
    121:   PetscErrorCode   ierr;

    124:   PetscObjectGetComm((PetscObject) da, &comm);
    125:   MPI_Comm_size(comm,&size);
    126:   MPI_Comm_rank(comm,&rank);

    128:   dd->p = 1;
    129:   dd->n = 1;
    130:   dd->m = size;
    131:   m     = dd->m;

    133:   if (s > 0) {
    134:     /* if not communicating data then should be ok to have nothing on some processes */
    135:     if (M < m) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"More processes than data points! %D %D",m,M);
    136:     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);
    137:   }

    139:   /*
    140:      Determine locally owned region
    141:      xs is the first local node number, x is the number of local nodes
    142:   */
    143:   if (!lx) {
    144:     PetscMalloc1(m, &dd->lx);
    145:     PetscOptionsGetBool(NULL,"-da_partition_blockcomm",&flg1,NULL);
    146:     PetscOptionsGetBool(NULL,"-da_partition_nodes_at_end",&flg2,NULL);
    147:     if (flg1) {      /* Block Comm type Distribution */
    148:       xs = rank*M/m;
    149:       x  = (rank + 1)*M/m - xs;
    150:     } else if (flg2) { /* The odd nodes are evenly distributed across last nodes */
    151:       x = (M + rank)/m;
    152:       if (M/m == x) xs = rank*x;
    153:       else          xs = rank*(x-1) + (M+rank)%(x*m);
    154:     } else { /* The odd nodes are evenly distributed across the first k nodes */
    155:       /* Regular PETSc Distribution */
    156:       x = M/m + ((M % m) > rank);
    157:       if (rank >= (M % m)) xs = (rank * (PetscInt)(M/m) + M % m);
    158:       else                 xs = rank * (PetscInt)(M/m) + rank;
    159:     }
    160:     MPI_Allgather(&xs,1,MPIU_INT,dd->lx,1,MPIU_INT,comm);
    161:     for (i=0; i<m-1; i++) dd->lx[i] = dd->lx[i+1] - dd->lx[i];
    162:     dd->lx[m-1] = M - dd->lx[m-1];
    163:   } else {
    164:     x  = lx[rank];
    165:     xs = 0;
    166:     for (i=0; i<rank; i++) xs += lx[i];
    167:     /* verify that data user provided is consistent */
    168:     left = xs;
    169:     for (i=rank; i<size; i++) left += lx[i];
    170:     if (left != M) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Sum of lx across processors not equal to M %D %D",left,M);
    171:   }

    173:   /*
    174:    check if the scatter requires more than one process neighbor or wraps around
    175:    the domain more than once
    176:   */
    177:   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);

    179:   xe  = xs + x;

    181:   /* determine ghost region (Xs) and region scattered into (IXs)  */
    182:   if (xs-sDist > 0) {
    183:     Xs  = xs - sDist;
    184:     IXs = xs - sDist;
    185:   } else {
    186:     if (bx) Xs = xs - sDist;
    187:     else Xs = 0;
    188:     IXs = 0;
    189:   }
    190:   if (xe+sDist <= M) {
    191:     Xe  = xe + sDist;
    192:     IXe = xe + sDist;
    193:   } else {
    194:     if (bx) Xe = xe + sDist;
    195:     else Xe = M;
    196:     IXe = M;
    197:   }

    199:   if (bx == DM_BOUNDARY_PERIODIC || bx == DM_BOUNDARY_MIRROR) {
    200:     Xs  = xs - sDist;
    201:     Xe  = xe + sDist;
    202:     IXs = xs - sDist;
    203:     IXe = xe + sDist;
    204:   }

    206:   /* allocate the base parallel and sequential vectors */
    207:   dd->Nlocal = dof*x;
    208:   VecCreateMPIWithArray(comm,dof,dd->Nlocal,PETSC_DECIDE,NULL,&global);
    209:   dd->nlocal = dof*(Xe-Xs);
    210:   VecCreateSeqWithArray(PETSC_COMM_SELF,dof,dd->nlocal,NULL,&local);

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

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

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

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

    223:   nn = IXs-Xs;
    224:   if (bx == DM_BOUNDARY_PERIODIC) { /* Handle all cases with periodic first */
    225:     for (i=0; i<sDist; i++) {  /* Left ghost points */
    226:       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
    227:       else                 idx[nn++] = M+(xs-sDist+i);
    228:     }

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

    232:     for (i=0; i<sDist; i++) { /* Right ghost points */
    233:       if ((xe+i)<M) idx [nn++] =  xe+i;
    234:       else          idx [nn++] = (xe+i) - M;
    235:     }
    236:   } else if (bx == DM_BOUNDARY_MIRROR) { /* Handle all cases with periodic first */
    237:     for (i=0; i<(sDist); i++) {  /* Left ghost points */
    238:       if ((xs-sDist+i)>=0) idx[nn++] = xs-sDist+i;
    239:       else                 idx[nn++] = sDist - i;
    240:     }

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

    244:     for (i=0; i<(sDist); i++) { /* Right ghost points */
    245:       if ((xe+i)<M) idx[nn++] =  xe+i;
    246:       else          idx[nn++] = M - (i + 1);
    247:     }
    248:   } else {      /* Now do all cases with no periodicity */
    249:     if (0 <= xs-sDist) {
    250:       for (i=0; i<sDist; i++) idx[nn++] = xs - sDist + i;
    251:     } else {
    252:       for (i=0; i<xs; i++) idx[nn++] = i;
    253:     }

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

    257:     if ((xe+sDist)<=M) {
    258:       for (i=0; i<sDist; i++) idx[nn++]=xe+i;
    259:     } else {
    260:       for (i=xe; i<M; i++) idx[nn++]=i;
    261:     }
    262:   }

    264:   ISCreateBlock(comm,dof,nn-IXs+Xs,&idx[IXs-Xs],PETSC_USE_POINTER,&from);
    265:   VecScatterCreate(global,from,local,to,&gtol);
    266:   PetscLogObjectParent((PetscObject)da,(PetscObject)gtol);
    267:   ISDestroy(&to);
    268:   ISDestroy(&from);
    269:   VecDestroy(&local);
    270:   VecDestroy(&global);

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

    275:   dd->gtol      = gtol;
    276:   dd->base      = dof*xs;
    277:   da->ops->view = DMView_DA_1d;

    279:   /*
    280:      Set the local to global ordering in the global vector, this allows use
    281:      of VecSetValuesLocal().
    282:   */
    283:   for (i=0; i<Xe-IXe; i++) idx[nn++] = -1; /* pad with -1s if needed for ghosted case*/

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

    288:   return(0);
    289: }

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

    298:    Collective on MPI_Comm

    300:    Input Parameters:
    301: +  comm - MPI communicator
    302: .  bx - type of ghost cells at the boundary the array should have, if any. Use
    303:           DM_BOUNDARY_NONE, DM_BOUNDARY_GHOSTED, or DM_BOUNDARY_PERIODIC.
    304: .  M - global dimension of the array (use -M to indicate that it may be set to a different value
    305:             from the command line with -da_grid_x <M>)
    306: .  dof - number of degrees of freedom per node
    307: .  s - stencil width
    308: -  lx - array containing number of nodes in the X direction on each processor,
    309:         or NULL. If non-null, must be of length as the number of processes in the MPI_Comm.

    311:    Output Parameter:
    312: .  da - the resulting distributed array object

    314:    Options Database Key:
    315: +  -dm_view - Calls DMView() at the conclusion of DMDACreate1d()
    316: .  -da_grid_x <nx> - number of grid points in x direction; can set if M < 0
    317: .  -da_refine_x <rx> - refinement factor
    318: -  -da_refine <n> - refine the DMDA n times before creating it, if M < 0

    320:    Level: beginner

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

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

    329: .seealso: DMDestroy(), DMView(), DMDACreate2d(), DMDACreate3d(), DMGlobalToLocalBegin(), DMDASetRefinementFactor(),
    330:           DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMLocalToLocalBegin(), DMLocalToLocalEnd(), DMDAGetRefinementFactor(),
    331:           DMDAGetInfo(), DMCreateGlobalVector(), DMCreateLocalVector(), DMDACreateNaturalVector(), DMLoad(), DMDAGetOwnershipRanges()

    333: @*/
    334: PetscErrorCode  DMDACreate1d(MPI_Comm comm, DMBoundaryType bx, PetscInt M, PetscInt dof, PetscInt s, const PetscInt lx[], DM *da)
    335: {
    337:   PetscMPIInt    size;

    340:   DMDACreate(comm, da);
    341:   DMSetDimension(*da, 1);
    342:   DMDASetSizes(*da, M, 1, 1);
    343:   MPI_Comm_size(comm, &size);
    344:   DMDASetNumProcs(*da, size, PETSC_DECIDE, PETSC_DECIDE);
    345:   DMDASetBoundaryType(*da, bx, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE);
    346:   DMDASetDof(*da, dof);
    347:   DMDASetStencilWidth(*da, s);
    348:   DMDASetOwnershipRanges(*da, lx, NULL, NULL);
    349:   /* This violates the behavior for other classes, but right now users expect negative dimensions to be handled this way */
    350:   DMSetFromOptions(*da);
    351:   DMSetUp(*da);
    352:   return(0);
    353: }