Actual source code: test15f.F90

slepc-3.22.2 2024-12-02
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  1: !
  2: !  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3: !  SLEPc - Scalable Library for Eigenvalue Problem Computations
  4: !  Copyright (c) 2002-, 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> ./test15f [-help] [-n <n>] [all SLEPc options]
 11: !
 12: !  Description: Tests custom monitors from Fortran.
 13: !
 14: !  The command line options are:
 15: !    -n <n>, where <n> = number of grid points = matrix size
 16: !    -my_eps_monitor, activates the custom monitor
 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: !  Note: Any user-defined Fortran routines (such as MyEPSMonitor)
 46: !  MUST be declared as external.

 48:       external MyEPSMonitor

 50: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 51: !     Beginning of program
 52: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

 54:       PetscCallA(SlepcInitialize(PETSC_NULL_CHARACTER,ierr))
 55:       PetscCallMPIA(MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr))
 56:       n = 30
 57:       PetscCallA(PetscOptionsGetInt(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER,'-n',n,flg,ierr))

 59:       if (rank .eq. 0) then
 60:         write(*,100) n
 61:       endif
 62:  100  format (/'1-D Laplacian Eigenproblem, n =',I3,' (Fortran)')

 64: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 65: !     Compute the operator matrix that defines the eigensystem, Ax=kx
 66: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

 68:       PetscCallA(MatCreate(PETSC_COMM_WORLD,A,ierr))
 69:       PetscCallA(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n,ierr))
 70:       PetscCallA(MatSetFromOptions(A,ierr))

 72:       i1 = 1
 73:       i2 = 2
 74:       i3 = 3
 75:       PetscCallA(MatGetOwnershipRange(A,Istart,Iend,ierr))
 76:       if (Istart .eq. 0) then
 77:         i = 0
 78:         col(1) = 0
 79:         col(2) = 1
 80:         value(1) =  2.0
 81:         value(2) = -1.0
 82:         PetscCallA(MatSetValues(A,i1,[i],i2,col,value,INSERT_VALUES,ierr))
 83:         Istart = Istart+1
 84:       endif
 85:       if (Iend .eq. n) then
 86:         i = n-1
 87:         col(1) = n-2
 88:         col(2) = n-1
 89:         value(1) = -1.0
 90:         value(2) =  2.0
 91:         PetscCallA(MatSetValues(A,i1,[i],i2,col,value,INSERT_VALUES,ierr))
 92:         Iend = Iend-1
 93:       endif
 94:       value(1) = -1.0
 95:       value(2) =  2.0
 96:       value(3) = -1.0
 97:       do i=Istart,Iend-1
 98:         col(1) = i-1
 99:         col(2) = i
100:         col(3) = i+1
101:         PetscCallA(MatSetValues(A,i1,[i],i3,col,value,INSERT_VALUES,ierr))
102:       enddo

104:       PetscCallA(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY,ierr))
105:       PetscCallA(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY,ierr))

107: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
108: !     Create the eigensolver and display info
109: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

111: !     ** Create eigensolver context
112:       PetscCallA(EPSCreate(PETSC_COMM_WORLD,eps,ierr))

114: !     ** Set operators. In this case, it is a standard eigenvalue problem
115:       PetscCallA(EPSSetOperators(eps,A,PETSC_NULL_MAT,ierr))
116:       PetscCallA(EPSSetProblemType(eps,EPS_HEP,ierr))

118: !     ** Set user-defined monitor
119:       PetscCallA(PetscOptionsHasName(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER,'-my_eps_monitor',flg,ierr))
120:       if (flg) then
121:         PetscCallA(EPSMonitorSet(eps,MyEPSMonitor,0,PETSC_NULL_FUNCTION,ierr))
122:       endif

124: !     ** Set solver parameters at runtime
125:       PetscCallA(EPSSetFromOptions(eps,ierr))

127: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
128: !     Solve the eigensystem
129: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

131:       PetscCallA(EPSSolve(eps,ierr))

133: !     ** Optional: Get some information from the solver and display it
134:       PetscCallA(EPSGetType(eps,tname,ierr))
135:       if (rank .eq. 0) then
136:         write(*,120) tname
137:       endif
138:  120  format (' Solution method: ',A)
139:       PetscCallA(EPSGetDimensions(eps,nev,PETSC_NULL_INTEGER,PETSC_NULL_INTEGER,ierr))
140:       if (rank .eq. 0) then
141:         write(*,130) nev
142:       endif
143:  130  format (' Number of requested eigenvalues:',I2)

145: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
146: !     Display solution and clean up
147: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

149:       PetscCallA(EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_NULL_VIEWER,ierr))
150:       PetscCallA(EPSDestroy(eps,ierr))
151:       PetscCallA(MatDestroy(A,ierr))

153:       PetscCallA(SlepcFinalize(ierr))
154:       end

156: ! --------------------------------------------------------------
157: !
158: !  MyEPSMonitor - This is a user-defined routine for monitoring
159: !  the EPS iterative solvers.
160: !
161: !  Input Parameters:
162: !    eps   - eigensolver context
163: !    its   - iteration number
164: !    nconv - number of converged eigenpairs
165: !    eigr  - real part of the eigenvalues
166: !    eigi  - imaginary part of the eigenvalues
167: !    errest- relative error estimates for each eigenpair
168: !    nest  - number of error estimates
169: !    dummy - optional user-defined monitor context (unused here)
170: !
171:       subroutine MyEPSMonitor(eps,its,nconv,eigr,eigi,errest,nest,dummy,ierr)
172: #include <slepc/finclude/slepceps.h>
173:       use slepceps
174:       implicit none

176:       EPS            eps
177:       PetscErrorCode ierr
178:       PetscInt       its,nconv,nest,dummy
179:       PetscScalar    eigr(*),eigi(*)
180:       PetscReal      re,errest(*)
181:       PetscMPIInt    rank

183:       PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr))
184:       if (its .gt. 0 .and. rank .eq. 0) then
185:         re = PetscRealPart(eigr(nconv+1))
186:         write(6,140) its,nconv,re,errest(nconv+1)
187:       endif

189:  140  format(i3,' EPS nconv=',i2,' first unconverged value (error) ',f7.4,' (',g10.3,')')
190:       ierr = 0
191:       end

193: !/*TEST
194: !
195: !   test:
196: !      suffix: 1
197: !      args: -my_eps_monitor
198: !      requires: double
199: !
200: !TEST*/