! D01AMF Example Program Text
! Mark 26.1 Release. NAG Copyright 2016.
Module d01amfe_mod
! D01AMF 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 :: lw = 800, nout = 6
Integer, Parameter, Public :: liw = lw/4
Contains
Function f(x)
! .. Function Return Value ..
Real (Kind=nag_wp) :: f
! .. Scalar Arguments ..
Real (Kind=nag_wp), Intent (In) :: x
! .. Intrinsic Procedures ..
Intrinsic :: sqrt
! .. Executable Statements ..
f = 1.0E0_nag_wp/((x+1.0E0_nag_wp)*sqrt(x))
Return
End Function f
End Module d01amfe_mod
Program d01amfe
! D01AMF Example Main Program
! .. Use Statements ..
Use d01amfe_mod, Only: f, liw, lw, nout
Use nag_library, Only: d01amf, nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Local Scalars ..
Real (Kind=nag_wp) :: abserr, bound, epsabs, epsrel, &
result
Integer :: ifail, inf
! .. Local Arrays ..
Real (Kind=nag_wp), Allocatable :: w(:)
Integer, Allocatable :: iw(:)
! .. Executable Statements ..
Write (nout,*) 'D01AMF Example Program Results'
Allocate (w(lw),iw(liw))
epsabs = 0.0E0_nag_wp
epsrel = 1.0E-04_nag_wp
bound = 0.0E0_nag_wp
inf = 1
ifail = -1
Call d01amf(f,bound,inf,epsabs,epsrel,result,abserr,w,lw,iw,liw,ifail)
If (ifail>=0) Then
Write (nout,*)
Write (nout,99999) 'A ', 'lower limit of integration', bound
Write (nout,99995) 'B ', 'upper limit of integration', 'infinity'
Write (nout,99998) 'EPSABS', 'absolute accuracy requested', epsabs
Write (nout,99998) 'EPSREL', 'relative accuracy requested', epsrel
End If
If (ifail>=0 .And. ifail<=5) Then
Write (nout,*)
Write (nout,99997) 'RESULT', 'approximation to the integral', result
Write (nout,99998) 'ABSERR', 'estimate of the absolute error', abserr
Write (nout,99996) 'IW(1) ', 'number of subintervals used', iw(1)
End If
99999 Format (1X,A6,' - ',A32,' = ',F10.4)
99998 Format (1X,A6,' - ',A32,' = ',E9.2)
99997 Format (1X,A6,' - ',A32,' = ',F9.5)
99996 Format (1X,A6,' - ',A32,' = ',I4)
99995 Format (1X,A6,' - ',A32,' = ',A8)
End Program d01amfe