Actual source code: test7f.F
slepc-3.8.0 2017-10-20
1: !
2: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: ! SLEPc - Scalable Library for Eigenvalue Problem Computations
4: ! Copyright (c) 2002-2017, Universitat Politecnica de Valencia, Spain
5: !
6: ! This file is part of SLEPc.
7: ! SLEPc is distributed under a 2-clause BSD license (see LICENSE).
8: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
9: !
10: ! Program usage: mpiexec -n <np> ./test7f [-help] [-n <n>] [all SLEPc options]
11: !
12: ! Description: Simple example that solves an eigensystem with the EPS object.
13: ! Same problem as ex1f but with simplified output.
14: !
15: ! The command line options are:
16: ! -n <n>, where <n> = number of grid points = matrix size
17: !
18: ! ----------------------------------------------------------------------
19: !
20: program main
21: #include <slepc/finclude/slepceps.h>
22: use slepceps
23: implicit none
25: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
26: ! Declarations
27: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
28: !
29: ! Variables:
30: ! A operator matrix
31: ! eps eigenproblem solver context
33: Mat A
34: EPS eps
35: EPSType tname
36: PetscInt n, i, Istart, Iend
37: PetscInt nev
38: PetscInt col(3)
39: PetscInt i1,i2,i3
40: PetscMPIInt rank
41: PetscErrorCode ierr
42: PetscBool flg
43: PetscScalar value(3)
45: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
46: ! Beginning of program
47: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
49: call SlepcInitialize(PETSC_NULL_CHARACTER,ierr)
50: call MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr)
51: n = 30
52: call PetscOptionsGetInt(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER, &
53: & '-n',n,flg,ierr)
55: if (rank .eq. 0) then
56: write(*,100) n
57: endif
58: 100 format (/'1-D Laplacian Eigenproblem, n =',I3,' (Fortran)')
60: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
61: ! Compute the operator matrix that defines the eigensystem, Ax=kx
62: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
64: call MatCreate(PETSC_COMM_WORLD,A,ierr)
65: call MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n,ierr)
66: call MatSetFromOptions(A,ierr)
67: call MatSetUp(A,ierr)
69: i1 = 1
70: i2 = 2
71: i3 = 3
72: call MatGetOwnershipRange(A,Istart,Iend,ierr)
73: if (Istart .eq. 0) then
74: i = 0
75: col(1) = 0
76: col(2) = 1
77: value(1) = 2.0
78: value(2) = -1.0
79: call MatSetValues(A,i1,i,i2,col,value,INSERT_VALUES,ierr)
80: Istart = Istart+1
81: endif
82: if (Iend .eq. n) then
83: i = n-1
84: col(1) = n-2
85: col(2) = n-1
86: value(1) = -1.0
87: value(2) = 2.0
88: call MatSetValues(A,i1,i,i2,col,value,INSERT_VALUES,ierr)
89: Iend = Iend-1
90: endif
91: value(1) = -1.0
92: value(2) = 2.0
93: value(3) = -1.0
94: do i=Istart,Iend-1
95: col(1) = i-1
96: col(2) = i
97: col(3) = i+1
98: call MatSetValues(A,i1,i,i3,col,value,INSERT_VALUES,ierr)
99: enddo
101: call MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY,ierr)
102: call MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY,ierr)
104: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
105: ! Create the eigensolver and display info
106: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
108: ! ** Create eigensolver context
109: call EPSCreate(PETSC_COMM_WORLD,eps,ierr)
111: ! ** Set operators. In this case, it is a standard eigenvalue problem
112: call EPSSetOperators(eps,A,PETSC_NULL_MAT,ierr)
113: call EPSSetProblemType(eps,EPS_HEP,ierr)
115: ! ** Set solver parameters at runtime
116: call EPSSetFromOptions(eps,ierr)
118: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
119: ! Solve the eigensystem
120: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
122: call EPSSolve(eps,ierr)
124: ! ** Optional: Get some information from the solver and display it
125: call EPSGetType(eps,tname,ierr)
126: if (rank .eq. 0) then
127: write(*,120) tname
128: endif
129: 120 format (' Solution method: ',A)
130: call EPSGetDimensions(eps,nev,PETSC_NULL_INTEGER, &
131: & PETSC_NULL_INTEGER,ierr)
132: if (rank .eq. 0) then
133: write(*,130) nev
134: endif
135: 130 format (' Number of requested eigenvalues:',I2)
137: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
138: ! Display solution and clean up
139: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
141: call EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_NULL_VIEWER,ierr)
142: call EPSDestroy(eps,ierr)
143: call MatDestroy(A,ierr)
145: call SlepcFinalize(ierr)
146: end