Actual source code: ex4.c
2: /* "$Id: ex4.c,v 1.13 2001/03/23 23:21:14 balay Exp $"; */
4: static char help[] = "Demonstrates using ISLocalToGlobalMappings.nn";
6: /*T
7: Concepts: local to global mappings
8: Concepts: global to local mappings
10: Description: Creates an index set based on blocks of integers. Views that index set
11: and then destroys it.
12: T*/
14: #include petscis.h
16: int main(int argc,char **argv)
17: {
18: int i,n = 4,ierr,indices[] = {0,3,9,12},m = 2,input[] = {0,2};
19: int output[2],inglobals[13],outlocals[13];
20: ISLocalToGlobalMapping mapping;
22: PetscInitialize(&argc,&argv,(char*)0,help);
24: /*
25: Create a local to global mapping. Each processor independently
26: creates a mapping
27: */
28: ISLocalToGlobalMappingCreate(PETSC_COMM_WORLD,n,indices,&mapping);
30: /*
31: Map a set of local indices to their global values
32: */
33: ISLocalToGlobalMappingApply(mapping,m,input,output);
34: PetscIntView(m,output,PETSC_VIEWER_STDOUT_SELF);
35:
36: /*
37: Map some global indices to local, retaining the ones without a local index by -1
38: */
39: for (i=0; i<13; i++) {
40: inglobals[i] = i;
41: }
42: ISGlobalToLocalMappingApply(mapping,IS_GTOLM_MASK,13,inglobals,PETSC_NULL,outlocals);
43:
44: PetscIntView(13,outlocals,PETSC_VIEWER_STDOUT_SELF);
46: /*
47: Map some global indices to local, dropping the ones without a local index.
48: */
49: ISGlobalToLocalMappingApply(mapping,IS_GTOLM_DROP,13,inglobals,&m,outlocals);
50:
51: PetscIntView(m,outlocals,PETSC_VIEWER_STDOUT_SELF);
53: /*
54: Free the space used by the local to global mapping
55: */
56: ISLocalToGlobalMappingDestroy(mapping);
59: PetscFinalize();
60: return 0;
61: }