! C05AUF Example Program Text
! Mark 29.0 Release. NAG Copyright 2023.
Module c05aufe_mod
! C05AUF Example Program Module:
! Parameters and User-defined Routines
! .. Use Statements ..
Use nag_library, Only: nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Accessibility Statements ..
Private
Public :: f
! .. Parameters ..
Integer, Parameter, Public :: nout = 6
Contains
Function f(x,iuser,ruser)
! .. Function Return Value ..
Real (Kind=nag_wp) :: f
! .. Scalar Arguments ..
Real (Kind=nag_wp), Intent (In) :: x
! .. Array Arguments ..
Real (Kind=nag_wp), Intent (Inout) :: ruser(*)
Integer, Intent (Inout) :: iuser(*)
! .. Intrinsic Procedures ..
Intrinsic :: exp
! .. Executable Statements ..
f = x - exp(-x)
Return
End Function f
End Module c05aufe_mod
Program c05aufe
! C05AUF Example Main Program
! .. Use Statements ..
Use c05aufe_mod, Only: f, nout
Use nag_library, Only: c05auf, nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Local Scalars ..
Real (Kind=nag_wp) :: a, b, eps, eta, h, x
Integer :: ifail
! .. Local Arrays ..
Real (Kind=nag_wp) :: ruser(1)
Integer :: iuser(1)
! .. Executable Statements ..
Write (nout,*) 'C05AUF Example Program Results'
x = 1.0E0_nag_wp
h = 0.1E0_nag_wp
eps = 1.0E-5_nag_wp
eta = 0.0E0_nag_wp
ifail = -1
Call c05auf(x,h,eps,eta,f,a,b,iuser,ruser,ifail)
Write (nout,*)
Select Case (ifail)
Case (0)
Write (nout,99999) 'Root is ', x
Write (nout,99998) 'Interval searched is [', a, ',', b, ']'
Case (3,4)
Write (nout,99999) 'Final value = ', x
End Select
99999 Format (1X,A,F13.5)
99998 Format (1X,A,2(F8.5,A))
End Program c05aufe