! D01AJF Example Program Text
! Mark 26.2 Release. NAG Copyright 2017.
Module d01ajfe_mod
! D01AJF 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
! .. Local Scalars ..
Real (Kind=nag_wp), Public, Save :: pi
Contains
Function f(x)
! .. Function Return Value ..
Real (Kind=nag_wp) :: f
! .. Scalar Arguments ..
Real (Kind=nag_wp), Intent (In) :: x
! .. Intrinsic Procedures ..
Intrinsic :: sin, sqrt
! .. Executable Statements ..
f = x*sin(30.0E0_nag_wp*x)/sqrt(1.0E0_nag_wp-x**2/(4.0E0_nag_wp*pi**2) &
)
Return
End Function f
End Module d01ajfe_mod
Program d01ajfe
! D01AJF Example Main Program
! .. Use Statements ..
Use d01ajfe_mod, Only: f, liw, lw, nout, pi
Use nag_library, Only: d01ajf, nag_wp, x01aaf
! .. Implicit None Statement ..
Implicit None
! .. Local Scalars ..
Real (Kind=nag_wp) :: a, abserr, b, epsabs, epsrel, result
Integer :: ifail
! .. Local Arrays ..
Real (Kind=nag_wp), Allocatable :: w(:)
Integer, Allocatable :: iw(:)
! .. Executable Statements ..
Write (nout,*) 'D01AJF Example Program Results'
Allocate (w(lw),iw(liw))
pi = x01aaf(pi)
epsabs = 0.0E0_nag_wp
epsrel = 1.0E-04_nag_wp
a = 0.0E0_nag_wp
b = 2.0E0_nag_wp*pi
ifail = -1
Call d01ajf(f,a,b,epsabs,epsrel,result,abserr,w,lw,iw,liw,ifail)
If (ifail>=0) Then
Write (nout,*)
Write (nout,99999) 'A ', 'lower limit of integration', a
Write (nout,99999) 'B ', 'upper limit of integration', b
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)
End Program d01ajfe