! Mark 25 Release. NAG Copyright 2014.
Module f01jcfe_mod
! .. Use Statements ..
Use nag_library, Only: nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Accessibility Statements ..
Private
Public :: fexp2
Contains
Subroutine fexp2(m,iflag,nz,z,fz,iuser,ruser)
! .. Scalar Arguments ..
Integer, Intent (Inout) :: iflag
Integer, Intent (In) :: m, nz
! .. Array Arguments ..
Complex (Kind=nag_wp), Intent (Out) :: fz(nz)
Complex (Kind=nag_wp), Intent (In) :: z(nz)
Real (Kind=nag_wp), Intent (Inout) :: ruser(*)
Integer, Intent (Inout) :: iuser(*)
! .. Intrinsic Procedures ..
Intrinsic :: cmplx, exp
! .. Executable Statements ..
Continue
fz(1:nz) = (cmplx(2.0E0_nag_wp,0.0_nag_wp,kind=nag_wp)**m)* &
exp((2.0E0_nag_wp,0.0E0_nag_wp)*z(1:nz))
! Set iflag nonzero to terminate execution for any reason.
iflag = 0
Return
End Subroutine fexp2
End Module f01jcfe_mod
Program f01jcfe
! F01JCF Example Main Program
! .. Use Statements ..
Use nag_library, Only: f01jcf, nag_wp, x02ajf, x04caf
Use f01jcfe_mod, Only: fexp2
! .. Implicit None Statement ..
Implicit None
! .. Parameters ..
Integer, Parameter :: nin = 5, nout = 6
! .. Local Scalars ..
Real (Kind=nag_wp) :: conda, cond_rel, eps, norma, &
normfa
Integer :: i, ifail, iflag, lda, n
! .. Local Arrays ..
Real (Kind=nag_wp), Allocatable :: a(:,:)
Real (Kind=nag_wp) :: ruser(1)
Integer :: iuser(1)
! .. Executable Statements ..
Write (nout,*) 'F01JCF Example Program Results'
Write (nout,*)
Flush (nout)
! Skip heading in data file
Read (nin,*)
Read (nin,*) n
lda = n
Allocate (a(lda,n))
! Read A from data file
Read (nin,*)(a(i,1:n),i=1,n)
! Display A
ifail = 0
Call x04caf('G','N',n,n,a,lda,'A',ifail)
! Find absolute condition number estimate
ifail = 0
Call f01jcf(n,a,lda,fexp2,iuser,ruser,iflag,conda,norma,normfa,ifail)
If (ifail==0) Then
! Print solution
Write (nout,*)
Write (nout,*) 'F(A) = exp(2A)'
Write (nout,99999) 'Estimated absolute condition number is: ', conda
! Find relative condition number estimate
eps = x02ajf()
If (normfa>eps) Then
cond_rel = conda*norma/normfa
Write (nout,99999) 'Estimated relative condition number is: ', &
cond_rel
Else
Write (nout,99998) 'The estimated norm of f(A) is effectively zero', &
'and so the relative condition number is undefined.'
End If
End If
99999 Format (1X,A,F7.2)
99998 Format (/1X,A/1X,A)
End Program f01jcfe