! C05AU_T1W_F Example Program Text
! Mark 30.1 Release. NAG Copyright 2024.
Module c05au_t1w_fe_mod
! C05AU_T1W_F Example Program Module:
! Parameters and User-defined Routines
! .. Use Statements ..
Use iso_c_binding, Only: c_ptr
Use nagad_library, Only: exp, nagad_t1w_w_rtype, Operator (-), &
Operator (*)
! .. Implicit None Statement ..
Implicit None
! .. Accessibility Statements ..
Private
Public :: f_t1w
! .. Parameters ..
Integer, Parameter, Public :: nout = 6
! .. Local Scalars ..
Type (nagad_t1w_w_rtype), Public, Save :: t
Contains
Subroutine f_t1w(ad_handle,x,z,iuser,ruser)
! .. Scalar Arguments ..
Type (c_ptr), Intent (Inout) :: ad_handle
Type (nagad_t1w_w_rtype), Intent (In) :: x
Type (nagad_t1w_w_rtype), Intent (Out) :: z
! .. Array Arguments ..
Type (nagad_t1w_w_rtype), Intent (Inout) :: ruser(*)
Integer, Intent (Inout) :: iuser(*)
! .. Executable Statements ..
z = x - exp(-t*x)
Return
End Subroutine f_t1w
End Module c05au_t1w_fe_mod
Program c05au_t1w_fe
! C05AU_T1W_F Example Main Program
! .. Use Statements ..
Use c05au_t1w_fe_mod, Only: f_t1w, nout, t
Use iso_c_binding, Only: c_ptr
Use nagad_library, Only: c05au_t1w_f, nagad_t1w_w_rtype, x10aa_t1w_f, &
x10ab_t1w_f, Assignment (=)
Use nag_library, Only: nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Local Scalars ..
Type (nagad_t1w_w_rtype) :: a, b, eps, eta, h, x
Type (c_ptr) :: ad_handle
Integer :: ifail
! .. Local Arrays ..
Type (nagad_t1w_w_rtype) :: ruser(1)
Integer :: iuser(1)
! .. Executable Statements ..
Write (nout,*) 'C05AU_T1W_F Example Program Results'
t = 1.0E0_nag_wp
x = 1.0E0_nag_wp
h = 0.1E0_nag_wp
eps = 1.0E-5_nag_wp
eta = 0.0E0_nag_wp
ifail = 0
Call x10aa_t1w_f(ad_handle,ifail)
ifail = -1
t%tangent = 1.0_nag_wp
Call c05au_t1w_f(ad_handle,x,h,eps,eta,f_t1w,a,b,iuser,ruser,ifail)
Write (nout,*)
Write (nout,*) 'Ifail = ', ifail
Select Case (ifail)
Case (0)
Write (nout,99999) 'Root is ', x%value
Write (nout,99998) 'Interval searched is [', a%value, ',', b%value, &
']'
Case (3,4)
Write (nout,99999) 'Final value = ', x%value
Case Default
Write (nout,99996) 'The routine has failed with ifail = ', ifail
Go To 100
End Select
Write (nout,99997) 'dx/dt = ', x%tangent
100 Continue
Call x10ab_t1w_f(ad_handle,ifail)
99999 Format (1X,A,F13.5)
99998 Format (1X,A,2(F8.5,A))
99997 Format (1X,A,F26.16)
99996 Format (1X,A,I0)
End Program c05au_t1w_fe