Actual source code: daindex.c
1: /*$Id: daindex.c,v 1.33 2001/06/21 21:19:09 bsmith Exp $*/
2:
3: /*
4: Code for manipulating distributed regular arrays in parallel.
5: */
7: #include src/dm/da/daimpl.h
11: /*@C
12: DAGetGlobalIndices - Returns the global node number of all local nodes,
13: including ghost nodes.
15: Not Collective
17: Input Parameter:
18: . da - the distributed array
20: Output Parameters:
21: + n - the number of local elements, including ghost nodes (or PETSC_NULL)
22: - idx - the global indices
24: Level: intermediate
26: Note:
27: For DA_STENCIL_STAR stencils the inactive corner ghost nodes are also included
28: in the list of local indices (even though those nodes are not updated
29: during calls to DAXXXToXXX().
31: Essentially the same data is returned in the form of a local-to-global mapping
32: with the routine DAGetISLocalToGlobalMapping();
34: Fortran Note:
35: This routine is used differently from Fortran
36: .vb
37: DA da
38: integer n,da_array(1)
39: PetscOffset i_da
40: integer ierr
41: call DAGetGlobalIndices(da,n,da_array,i_da,ierr)
43: C Access first local entry in list
44: value = da_array(i_da + 1)
45: .ve
47: See the Fortran chapter of the users manual for details
49: .keywords: distributed array, get, global, indices, local-to-global
51: .seealso: DACreate2d(), DAGetGhostCorners(), DAGetCorners(), DALocalToGlobal()
52: DAGlobalToLocalBegin(), DAGlobalToLocalEnd(), DALocalToLocalBegin(), DAGetAO(), DAGetGlobalIndicesF90()
53: DAGetISLocalToGlobalMapping(), DACreate3d(), DACreate1d(), DALocalToLocalEnd()
54: @*/
55: int DAGetGlobalIndices(DA da,int *n,int **idx)
56: {
59: if (n) *n = da->Nl;
60: if (idx) *idx = da->idx;
61: return(0);
62: }
66: /*
67: Gets the natural number for each global number on the process.
69: Used by DAGetAO() and DAGlobalToNatural_Create()
70: */
71: int DAGetNatural_Private(DA da,int *outNlocal,IS *isnatural)
72: {
73: int Nlocal,i,j,k,ierr,*lidx,lict = 0;
76: Nlocal = (da->xe-da->xs);
77: if (da->dim > 1) {
78: Nlocal *= (da->ye-da->ys);
79: }
80: if (da->dim > 2) {
81: Nlocal *= (da->ze-da->zs);
82: }
83:
84: PetscMalloc(Nlocal*sizeof(int),&lidx);
85:
86: if (da->dim == 1) {
87: for (i=da->xs; i<da->xe; i++) {
88: /* global number in natural ordering */
89: lidx[lict++] = i;
90: }
91: } else if (da->dim == 2) {
92: for (j=da->ys; j<da->ye; j++) {
93: for (i=da->xs; i<da->xe; i++) {
94: /* global number in natural ordering */
95: lidx[lict++] = i + j*da->M*da->w;
96: }
97: }
98: } else if (da->dim == 3) {
99: for (k=da->zs; k<da->ze; k++) {
100: for (j=da->ys; j<da->ye; j++) {
101: for (i=da->xs; i<da->xe; i++) {
102: lidx[lict++] = i + j*da->M*da->w + k*da->M*da->N*da->w;
103: }
104: }
105: }
106: }
107: *outNlocal = Nlocal;
108: ISCreateGeneral(da->comm,Nlocal,lidx,isnatural);
109: PetscFree(lidx);
110: return(0);
111: }
115: /*@C
116: DAGetAO - Gets the application ordering context for a distributed array.
118: Collective on DA
120: Input Parameter:
121: . da - the distributed array
123: Output Parameters:
124: . ao - the application ordering context for DAs
126: Level: intermediate
128: Notes:
129: In this case, the AO maps to the natural grid ordering that would be used
130: for the DA if only 1 processor were employed (ordering most rapidly in the
131: x-direction, then y, then z). Multiple degrees of freedom are numbered
132: for each node (rather than 1 component for the whole grid, then the next
133: component, etc.)
135: .keywords: distributed array, get, global, indices, local-to-global
137: .seealso: DACreate2d(), DAGetGhostCorners(), DAGetCorners(), DALocalToGlocal()
138: DAGlobalToLocalBegin(), DAGlobalToLocalEnd(), DALocalToLocalBegin(), DALocalToLocalEnd(), DAGetGlobalIndices()
139: @*/
140: int DAGetAO(DA da,AO *ao)
141: {
146: /*
147: Build the natural ordering to PETSc ordering mappings.
148: */
149: if (!da->ao) {
150: IS ispetsc,isnatural;
151: int ierr,Nlocal;
153: DAGetNatural_Private(da,&Nlocal,&isnatural);
154: ISCreateStride(da->comm,Nlocal,da->base,1,&ispetsc);
155: AOCreateBasicIS(isnatural,ispetsc,&da->ao);
156: PetscLogObjectParent(da,da->ao);
157: ISDestroy(ispetsc);
158: ISDestroy(isnatural);
159: }
160: *ao = da->ao;
161: return(0);
162: }
164: /*MC
165: DAGetGlobalIndicesF90 - Returns a Fortran90 pointer to the list of
166: global indices (global node number of all local nodes, including
167: ghost nodes).
169: Synopsis:
170: DAGetGlobalIndicesF90(DA da,integer n,{integer, pointer :: idx(:)},integer ierr)
172: Input Parameter:
173: . da - the distributed array
175: Output Parameters:
176: + n - the number of local elements, including ghost nodes (or PETSC_NULL)
177: . idx - the Fortran90 pointer to the global indices
178: - ierr - error code
180: Level: intermediate
182: Notes:
183: Not yet supported for all F90 compilers
185: .keywords: distributed array, get, global, indices, local-to-global, f90
187: .seealso: DAGetGlobalIndices()
188: M*/