Actual source code: test7f.F
slepc-3.6.1 2015-09-03
1: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2: ! SLEPc - Scalable Library for Eigenvalue Problem Computations
3: ! Copyright (c) 2002-2015, Universitat Politecnica de Valencia, Spain
4: !
5: ! This file is part of SLEPc.
6: !
7: ! SLEPc is free software: you can redistribute it and/or modify it under the
8: ! terms of version 3 of the GNU Lesser General Public License as published by
9: ! the Free Software Foundation.
10: !
11: ! SLEPc is distributed in the hope that it will be useful, but WITHOUT ANY
12: ! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13: ! FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
14: ! more details.
15: !
16: ! You should have received a copy of the GNU Lesser General Public License
17: ! along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
18: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
19: !
20: ! Program usage: mpirun -np n test7f [-help] [-n <n>] [all SLEPc options]
21: !
22: ! Description: Simple example that solves an eigensystem with the EPS object.
23: ! Same problem as ex1f but with simplified output.
24: !
25: ! The command line options are:
26: ! -n <n>, where <n> = number of grid points = matrix size
27: !
28: ! ----------------------------------------------------------------------
29: !
30: program main
31: implicit none
33: #include <petsc/finclude/petscsys.h>
34: #include <petsc/finclude/petscvec.h>
35: #include <petsc/finclude/petscmat.h>
36: #include <slepc/finclude/slepcsys.h>
37: #include <slepc/finclude/slepceps.h>
39: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
40: ! Declarations
41: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
42: !
43: ! Variables:
44: ! A operator matrix
45: ! eps eigenproblem solver context
47: Mat A
48: EPS eps
49: EPSType tname
50: PetscInt n, i, Istart, Iend
51: PetscInt nev
52: PetscInt col(3)
53: PetscInt i1,i2,i3
54: PetscMPIInt rank
55: PetscErrorCode ierr
56: PetscBool flg
57: PetscScalar value(3)
59: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
60: ! Beginning of program
61: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
63: call SlepcInitialize(PETSC_NULL_CHARACTER,ierr)
64: call MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr)
65: n = 30
66: call PetscOptionsGetInt(PETSC_NULL_CHARACTER,'-n',n,flg,ierr)
68: if (rank .eq. 0) then
69: write(*,100) n
70: endif
71: 100 format (/'1-D Laplacian Eigenproblem, n =',I3,' (Fortran)')
73: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
74: ! Compute the operator matrix that defines the eigensystem, Ax=kx
75: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
77: call MatCreate(PETSC_COMM_WORLD,A,ierr)
78: call MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n,ierr)
79: call MatSetFromOptions(A,ierr)
80: call MatSetUp(A,ierr)
82: i1 = 1
83: i2 = 2
84: i3 = 3
85: call MatGetOwnershipRange(A,Istart,Iend,ierr)
86: if (Istart .eq. 0) then
87: i = 0
88: col(1) = 0
89: col(2) = 1
90: value(1) = 2.0
91: value(2) = -1.0
92: call MatSetValues(A,i1,i,i2,col,value,INSERT_VALUES,ierr)
93: Istart = Istart+1
94: endif
95: if (Iend .eq. n) then
96: i = n-1
97: col(1) = n-2
98: col(2) = n-1
99: value(1) = -1.0
100: value(2) = 2.0
101: call MatSetValues(A,i1,i,i2,col,value,INSERT_VALUES,ierr)
102: Iend = Iend-1
103: endif
104: value(1) = -1.0
105: value(2) = 2.0
106: value(3) = -1.0
107: do i=Istart,Iend-1
108: col(1) = i-1
109: col(2) = i
110: col(3) = i+1
111: call MatSetValues(A,i1,i,i3,col,value,INSERT_VALUES,ierr)
112: enddo
114: call MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY,ierr)
115: call MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY,ierr)
117: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
118: ! Create the eigensolver and display info
119: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
121: ! ** Create eigensolver context
122: call EPSCreate(PETSC_COMM_WORLD,eps,ierr)
124: ! ** Set operators. In this case, it is a standard eigenvalue problem
125: call EPSSetOperators(eps,A,PETSC_NULL_OBJECT,ierr)
126: call EPSSetProblemType(eps,EPS_HEP,ierr)
128: ! ** Set solver parameters at runtime
129: call EPSSetFromOptions(eps,ierr)
131: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
132: ! Solve the eigensystem
133: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
135: call EPSSolve(eps,ierr)
137: ! ** Optional: Get some information from the solver and display it
138: call EPSGetType(eps,tname,ierr)
139: if (rank .eq. 0) then
140: write(*,120) tname
141: endif
142: 120 format (' Solution method: ',A)
143: call EPSGetDimensions(eps,nev,PETSC_NULL_INTEGER, &
144: & PETSC_NULL_INTEGER,ierr)
145: if (rank .eq. 0) then
146: write(*,130) nev
147: endif
148: 130 format (' Number of requested eigenvalues:',I2)
150: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
151: ! Display solution and clean up
152: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
154: call EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_NULL_OBJECT,ierr)
155: call EPSDestroy(eps,ierr)
156: call MatDestroy(A,ierr)
158: call SlepcFinalize(ierr)
159: end