Actual source code: ex126f.F
petsc-3.4.2 2013-07-02
1: !
2: ! This program is modified from a user's contribution.
3: ! It illustrates how to call MUMPS's LU solver
4: !
6: program main
7: implicit none
9: #include <finclude/petscsys.h>
10: #include <finclude/petscvec.h>
11: #include <finclude/petscmat.h>
13: Vec x,b,u
14: Mat A, fact
15: PetscInt i,j,II,JJ,m
16: PetscInt Istart, Iend
17: PetscInt ione, ifive
18: PetscBool wmumps
19: PetscBool flg
20: PetscScalar one, v
21: IS perm,iperm
22: PetscErrorCode ierr
24: call PetscInitialize(PETSC_NULL_CHARACTER, ierr)
25: m = 10
26: one = 1.0
27: ione = 1
28: ifive = 5
30: wmumps = PETSC_FALSE
32: call PetscOptionsGetInt(PETSC_NULL_CHARACTER,'-m',m,flg, ierr)
33: call PetscOptionsGetBool(PETSC_NULL_CHARACTER,'-use_mumps', &
34: & wmumps,flg,ierr)
36: call MatCreate(PETSC_COMM_WORLD, A, ierr)
37: call MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, m*m, m*m, ierr)
38: call MatSetType(A, MATAIJ, ierr)
39: call MatSetFromOptions(A, ierr)
40: call MatSeqAIJSetPreallocation(A,ifive, PETSC_NULL_INTEGER, ierr)
41: call MatMPIAIJSetPreallocation(A,ifive,PETSC_NULL_INTEGER,ifive, &
42: & PETSC_NULL_INTEGER,ierr)
44: call MatGetOwnershipRange(A,Istart,Iend,ierr)
46: do 10, II=Istart,Iend - 1
47: v = -1.0
48: i = II/m
49: j = II - i*m
50: if (i.gt.0) then
51: JJ = II - m
52: call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
53: endif
54: if (i.lt.m-1) then
55: JJ = II + m
56: call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
57: endif
58: if (j.gt.0) then
59: JJ = II - 1
60: call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
61: endif
62: if (j.lt.m-1) then
63: JJ = II + 1
64: call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
65: endif
66: v = 4.0
67: call MatSetValues(A,ione,II,ione,II,v,INSERT_VALUES,ierr)
68: 10 continue
70: call MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY, ierr)
71: call MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY, ierr)
73: call VecCreate(PETSC_COMM_WORLD, u, ierr)
74: call VecSetSizes(u, PETSC_DECIDE, m*m, ierr)
75: call VecSetFromOptions(u, ierr)
76: call VecDuplicate(u,b,ierr)
77: call VecDuplicate(b,x,ierr)
78: call VecSet(u, one, ierr)
79: call MatMult(A, u, b, ierr)
81: if (wmumps) then
82: write(*,*) 'use MUMPS LU...'
83: call MatGetFactor(A, MATSOLVERMUMPS, MAT_FACTOR_LU, &
84: & fact, ierr)
85: call MatLUFactorSymbolic(fact, A, PETSC_NULL_OBJECT, &
86: & PETSC_NULL_OBJECT,PETSC_NULL_INTEGER, ierr)
87: else
88: write(*,*) 'use PETSc LU...'
89: call MatGetOrdering(A,MATORDERINGNATURAL,perm,iperm,ierr)
90: call MatGetFactor(A, MATSOLVERPETSC, MAT_FACTOR_LU, &
91: & fact, ierr)
93: call MatLUFactorSymbolic(fact, A, perm, iperm, &
94: & PETSC_NULL_INTEGER, ierr)
95: call ISDestroy(perm,ierr)
96: call ISDestroy(iperm,ierr)
97: endif
99: call MatLUFactorNumeric(fact, A, PETSC_NULL_INTEGER, ierr)
100: call MatSolve(fact, b, x,ierr)
101: call MatDestroy(fact, ierr)
103: call MatDestroy(A, ierr)
104: call VecDestroy(u, ierr)
105: call VecDestroy(x, ierr)
106: call VecDestroy(b, ierr)
108: call PetscFinalize(ierr)
109: end