Actual source code: daltol.c

      2: /*
      3:   Code for manipulating distributed regular arrays in parallel.
      4: */

      6: #include <petsc/private/dmdaimpl.h>

      8: /*
      9:    DMLocalToLocalCreate_DA - Creates the local to local scatter

     11:    Collective on da

     13:    Input Parameter:
     14: .  da - the distributed array

     16: */
     17: PetscErrorCode  DMLocalToLocalCreate_DA(DM da)
     18: {
     19:   PetscInt       *idx,left,j,count,up,down,i,bottom,top,k,dim=da->dim;
     20:   DM_DA          *dd = (DM_DA*)da->data;

     24:   if (dd->ltol) return 0;
     25:   /*
     26:      We simply remap the values in the from part of
     27:      global to local to read from an array with the ghost values
     28:      rather then from the plain array.
     29:   */
     30:   VecScatterCopy(dd->gtol,&dd->ltol);
     31:   PetscLogObjectParent((PetscObject)da,(PetscObject)dd->ltol);
     32:   if (dim == 1) {
     33:     left = dd->xs - dd->Xs;
     34:     PetscMalloc1(dd->xe-dd->xs,&idx);
     35:     for (j=0; j<dd->xe-dd->xs; j++) idx[j] = left + j;
     36:   } else if (dim == 2) {
     37:     left  = dd->xs - dd->Xs; down  = dd->ys - dd->Ys; up    = down + dd->ye-dd->ys;
     38:     PetscMalloc1((dd->xe-dd->xs)*(up - down),&idx);
     39:     count = 0;
     40:     for (i=down; i<up; i++) {
     41:       for (j=0; j<dd->xe-dd->xs; j++) {
     42:         idx[count++] = left + i*(dd->Xe-dd->Xs) + j;
     43:       }
     44:     }
     45:   } else if (dim == 3) {
     46:     left   = dd->xs - dd->Xs;
     47:     bottom = dd->ys - dd->Ys; top = bottom + dd->ye-dd->ys;
     48:     down   = dd->zs - dd->Zs; up  = down + dd->ze-dd->zs;
     49:     count  = (dd->xe-dd->xs)*(top-bottom)*(up-down);
     50:     PetscMalloc1(count,&idx);
     51:     count  = 0;
     52:     for (i=down; i<up; i++) {
     53:       for (j=bottom; j<top; j++) {
     54:         for (k=0; k<dd->xe-dd->xs; k++) {
     55:           idx[count++] = (left+j*(dd->Xe-dd->Xs))+i*(dd->Xe-dd->Xs)*(dd->Ye-dd->Ys) + k;
     56:         }
     57:       }
     58:     }
     59:   } else SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_ARG_CORRUPT,"DMDA has invalid dimension %D",dim);

     61:   VecScatterRemap(dd->ltol,idx,NULL);
     62:   PetscFree(idx);
     63:   return 0;
     64: }

     66: /*
     67:    DMLocalToLocalBegin_DA - Maps from a local vector (including ghost points
     68:    that contain irrelevant values) to another local vector where the ghost
     69:    points in the second are set correctly. Must be followed by DMLocalToLocalEnd_DA().

     71:    Neighbor-wise Collective on da

     73:    Input Parameters:
     74: +  da - the distributed array context
     75: .  g - the original local vector
     76: -  mode - one of INSERT_VALUES or ADD_VALUES

     78:    Output Parameter:
     79: .  l  - the local vector with correct ghost values

     81:    Notes:
     82:    The local vectors used here need not be the same as those
     83:    obtained from DMCreateLocalVector(), BUT they
     84:    must have the same parallel data layout; they could, for example, be
     85:    obtained with VecDuplicate() from the DMDA originating vectors.

     87: */
     88: PetscErrorCode  DMLocalToLocalBegin_DA(DM da,Vec g,InsertMode mode,Vec l)
     89: {
     90:   DM_DA          *dd = (DM_DA*)da->data;

     93:   if (!dd->ltol) {
     94:     DMLocalToLocalCreate_DA(da);
     95:   }
     96:   VecScatterBegin(dd->ltol,g,l,mode,SCATTER_FORWARD);
     97:   return 0;
     98: }

    100: /*
    101:    DMLocalToLocalEnd_DA - Maps from a local vector (including ghost points
    102:    that contain irrelevant values) to another local vector where the ghost
    103:    points in the second are set correctly.  Must be preceded by
    104:    DMLocalToLocalBegin_DA().

    106:    Neighbor-wise Collective on da

    108:    Input Parameters:
    109: +  da - the distributed array context
    110: .  g - the original local vector
    111: -  mode - one of INSERT_VALUES or ADD_VALUES

    113:    Output Parameter:
    114: .  l  - the local vector with correct ghost values

    116:    Note:
    117:    The local vectors used here need not be the same as those
    118:    obtained from DMCreateLocalVector(), BUT they
    119:    must have the same parallel data layout; they could, for example, be
    120:    obtained with VecDuplicate() from the DMDA originating vectors.

    122: */
    123: PetscErrorCode  DMLocalToLocalEnd_DA(DM da,Vec g,InsertMode mode,Vec l)
    124: {
    125:   DM_DA          *dd = (DM_DA*)da->data;

    129:   VecScatterEnd(dd->ltol,g,l,mode,SCATTER_FORWARD);
    130:   return 0;
    131: }