Actual source code: ex3.c
2: /* "$Id: ex3.c,v 1.21 2001/03/23 23:21:14 balay Exp $"; */
4: static char help[] = "Demonstrates creating a blocked index set.nn";
6: /*T
7: Concepts: index sets^creating a block index set;
8: Concepts: IS^creating a block index set;
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: #undef __FUNCT__
18: int main(int argc,char **argv)
19: {
20: int i,n = 4,ierr, inputindices[] = {0,3,9,12},bs = 3,issize,*indices;
21: IS set;
22: PetscTruth isblock;
24: PetscInitialize(&argc,&argv,(char*)0,help);
25:
26: /*
27: Create a block index set. The index set has 4 blocks each of size 3.
28: The indices are {0,1,2,3,4,5,9,10,11,12,13,14}
29: Note each processor is generating its own index set
30: (in this case they are all identical)
31: */
32: ISCreateBlock(PETSC_COMM_SELF,bs,n,inputindices,&set);
33: ISView(set,PETSC_VIEWER_STDOUT_SELF);
35: /*
36: Extract indices from set.
37: */
38: ISGetLocalSize(set,&issize);
39: ISGetIndices(set,&indices);
40: PetscPrintf(PETSC_COMM_SELF,"Printing indices directlyn");
41: for (i=0; i<issize; i++) {
42: PetscPrintf(PETSC_COMM_SELF,"%dn",indices[i]);
43: }
44: ISRestoreIndices(set,&indices);
46: /*
47: Extract the block indices. This returns one index per block.
48: */
49: ISBlockGetIndices(set,&indices);
50: PetscPrintf(PETSC_COMM_SELF,"Printing block indices directlyn");
51: for (i=0; i<n; i++) {
52: PetscPrintf(PETSC_COMM_SELF,"%dn",indices[i]);
53: }
54: ISBlockRestoreIndices(set,&indices);
56: /*
57: Check if this is really a block index set
58: */
59: ISBlock(set,&isblock);
60: if (isblock != PETSC_TRUE) SETERRQ(1,"Index set is not blocked!");
62: /*
63: Determine the block size of the index set
64: */
65: ISBlockGetBlockSize(set,&bs);
66: if (bs != 3) SETERRQ(1,"Block size is not 3!");
68: /*
69: Get the number of blocks
70: */
71: ISBlockGetSize(set,&n);
72: if (n != 4) SETERRQ(1,"Number of blocks not 4!");
74: ISDestroy(set);
75: PetscFinalize();
76: return 0;
77: }