Actual source code: ex126f.F
petsc-3.6.4 2016-04-12
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 <petsc/finclude/petscsys.h>
10: #include <petsc/finclude/petscvec.h>
11: #include <petsc/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
23: PetscReal info(MAT_FACTORINFO_SIZE)
25: call PetscInitialize(PETSC_NULL_CHARACTER, ierr)
26: m = 10
27: one = 1.0
28: ione = 1
29: ifive = 5
31: wmumps = PETSC_FALSE
33: call PetscOptionsGetInt(PETSC_NULL_CHARACTER,'-m',m,flg, ierr)
34: call PetscOptionsGetBool(PETSC_NULL_CHARACTER,'-use_mumps', &
35: & wmumps,flg,ierr)
37: call MatCreate(PETSC_COMM_WORLD, A, ierr)
38: call MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, m*m, m*m, ierr)
39: call MatSetType(A, MATAIJ, ierr)
40: call MatSetFromOptions(A, ierr)
41: call MatSeqAIJSetPreallocation(A,ifive, PETSC_NULL_INTEGER, ierr)
42: call MatMPIAIJSetPreallocation(A,ifive,PETSC_NULL_INTEGER,ifive, &
43: & PETSC_NULL_INTEGER,ierr)
45: call MatGetOwnershipRange(A,Istart,Iend,ierr)
47: do 10, II=Istart,Iend - 1
48: v = -1.0
49: i = II/m
50: j = II - i*m
51: if (i.gt.0) then
52: JJ = II - m
53: call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
54: endif
55: if (i.lt.m-1) then
56: JJ = II + m
57: call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
58: endif
59: if (j.gt.0) then
60: JJ = II - 1
61: call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
62: endif
63: if (j.lt.m-1) then
64: JJ = II + 1
65: call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
66: endif
67: v = 4.0
68: call MatSetValues(A,ione,II,ione,II,v,INSERT_VALUES,ierr)
69: 10 continue
71: call MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY, ierr)
72: call MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY, ierr)
74: call VecCreate(PETSC_COMM_WORLD, u, ierr)
75: call VecSetSizes(u, PETSC_DECIDE, m*m, ierr)
76: call VecSetFromOptions(u, ierr)
77: call VecDuplicate(u,b,ierr)
78: call VecDuplicate(b,x,ierr)
79: call VecSet(u, one, ierr)
80: call MatMult(A, u, b, ierr)
82: call MatFactorInfoInitialize(info,ierr)
83: if (wmumps) then
84: write(*,*) 'use MUMPS LU...'
85: call MatGetFactor(A,MATSOLVERMUMPS,MAT_FACTOR_LU,fact,ierr)
86: call MatLUFactorSymbolic(fact, A, PETSC_NULL_OBJECT, &
87: & PETSC_NULL_OBJECT,info, ierr)
88: else
89: write(*,*) 'use PETSc LU...'
90: call MatGetOrdering(A,MATORDERINGNATURAL,perm,iperm,ierr)
91: call MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_LU,fact,ierr)
93: call MatLUFactorSymbolic(fact, A, perm, iperm, &
94: & info, ierr)
95: call ISDestroy(perm,ierr)
96: call ISDestroy(iperm,ierr)
97: endif
99: call MatLUFactorNumeric(fact, A, info, 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