Actual source code: ex3f90.F90
petsc-3.13.6 2020-09-29
1: !
2: ! Description: Creates an index set based on blocks of integers. Views that index set
3: ! and then destroys it.
4: !
5: !/*T
6: ! Concepts: index sets^manipulating a block index set;
7: ! Concepts: Fortran90^accessing indices in index set;
8: !
9: !T*/
10: !
11: program main
12: #include <petsc/finclude/petscis.h>
13: use petscis
14: implicit none
16: PetscErrorCode ierr
17: PetscInt n,bs,issize
18: PetscInt inputindices(4)
19: PetscInt, pointer :: indices(:)
20: IS set
21: PetscBool isablock;
23: n = 4
24: bs = 3
25: inputindices(1) = 0
26: inputindices(2) = 1
27: inputindices(3) = 3
28: inputindices(4) = 4
30: call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
31: if (ierr .ne. 0) then
32: print*,'Unable to initialize PETSc'
33: stop
34: endif
35: !
36: ! Create a block index set. The index set has 4 blocks each of size 3.
37: ! The indices are {0,1,2,3,4,5,9,10,11,12,13,14}
38: ! Note each processor is generating its own index set
39: ! (in this case they are all identical)
40: !
41: call ISCreateBlock(PETSC_COMM_SELF,bs,n,inputindices,PETSC_COPY_VALUES,set,ierr);CHKERRA(ierr)
42: call ISView(set,PETSC_VIEWER_STDOUT_SELF,ierr);CHKERRA(ierr)
44: !
45: ! Extract indices from set.
46: !
47: call ISGetLocalSize(set,issize,ierr);CHKERRA(ierr)
48: call ISGetIndicesF90(set,indices,ierr);CHKERRA(ierr)
49: write(6,100)indices
50: 100 format(12I3)
51: call ISRestoreIndicesF90(set,indices,ierr);CHKERRA(ierr)
53: !
54: ! Extract the block indices. This returns one index per block.
55: !
56: call ISBlockGetIndicesF90(set,indices,ierr);CHKERRA(ierr)
57: write(6,200)indices
58: 200 format(4I3)
59: call ISBlockRestoreIndicesF90(set,indices,ierr);CHKERRA(ierr)
61: !
62: ! Check if this is really a block index set
63: !
64: call PetscObjectTypeCompare(set,ISBLOCK,isablock,ierr);CHKERRA(ierr)
65: if (.not. isablock) then
66: write(6,*) 'Index set is not blocked!'
67: endif
69: !
70: ! Determine the block size of the index set
71: !
72: call ISGetBlockSize(set,bs,ierr);CHKERRA(ierr)
73: if (bs .ne. 3) then
74: write(6,*) 'Blocksize != 3'
75: endif
77: !
78: ! Get the number of blocks
79: !
80: call ISBlockGetLocalSize(set,n,ierr);CHKERRA(ierr)
81: if (n .ne. 4) then
82: write(6,*) 'Number of blocks != 4'
83: endif
85: call ISDestroy(set,ierr);CHKERRA(ierr)
86: call PetscFinalize(ierr)
87: end
89: !/*TEST
90: !
91: ! test:
92: ! filter: sort -b
93: ! filter_output: sort -b
94: !
95: !TEST*/