!   D01AUF Example Program Text
!   Mark 27.3 Release. NAG Copyright 2021.

    Module d01aufe_mod

!     D01AUF 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
      Subroutine f(x,fv,n)

!       .. Scalar Arguments ..
        Integer, Intent (In)           :: n
!       .. Array Arguments ..
        Real (Kind=nag_wp), Intent (Out) :: fv(n)
        Real (Kind=nag_wp), Intent (In) :: x(n)
!       .. Intrinsic Procedures ..
        Intrinsic                      :: cos, sin
!       .. Executable Statements ..
        fv(1:n) = x(1:n)*(sin(30.0E0_nag_wp*x(1:n)))*cos(x(1:n))

        Return

      End Subroutine f
    End Module d01aufe_mod
    Program d01aufe

!     D01AUF Example Main Program

!     .. Use Statements ..
      Use d01aufe_mod, Only: f, liw, lw, nout
      Use nag_library, Only: d01auf, nag_wp, x01aaf
!     .. Implicit None Statement ..
      Implicit None
!     .. Local Scalars ..
      Real (Kind=nag_wp)               :: a, abserr, b, epsabs, epsrel, pi,    &
                                          result
      Integer                          :: ifail, key
!     .. Local Arrays ..
      Real (Kind=nag_wp), Allocatable  :: w(:)
      Integer, Allocatable             :: iw(:)
!     .. Executable Statements ..
      Write (nout,*) 'D01AUF Example Program Results'

      Allocate (w(lw),iw(liw))

      pi = x01aaf(pi)
      epsabs = 0.0E0_nag_wp
      epsrel = 1.0E-03_nag_wp
      a = 0.0E0_nag_wp
      b = 2.0E0_nag_wp*pi
      key = 6

      ifail = -1
      Call d01auf(f,a,b,key,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<=3) 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,' - ',A30,' = ',F10.4)
99998 Format (1X,A6,' - ',A30,' = ',E9.2)
99997 Format (1X,A6,' - ',A30,' = ',F9.5)
99996 Format (1X,A6,' - ',A30,' = ',I4)
    End Program d01aufe