Program s22befe

!     S22BEF Example Program Text

!     Mark 27.1 Release. NAG Copyright 2020.

!     .. Use Statements ..
      Use nag_library, Only: nag_wp, s22bef
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nout = 6
!     .. Local Scalars ..
      Real (Kind=nag_wp)               :: a, b, c, f, x
      Integer                          :: ifail, kx
!     .. Intrinsic Procedures ..
      Intrinsic                        :: real
!     .. Executable Statements ..
      Write (nout,*) 'S22BEF Example Program Results'

      a = 1.2E0_nag_wp
      b = -2.6E0_nag_wp
      c = 3.5E0_nag_wp

      Write (nout,*)
      Write (nout,99999)
      Write (nout,99998)
      Write (nout,99997) a, b, c
      Write (nout,*)
      Write (nout,99996)
      Write (nout,99995)

      Do kx = 1, 21
        x = -4.0E0_nag_wp + real(kx-1,kind=nag_wp)*0.25E0_nag_wp
        ifail = 1
        f = s22bef(a,b,c,x,ifail)
        Select Case (ifail)
        Case (0,1,2,3)
          Write (nout,99994) x, f
        Case (4,5,6)
          If (f>=0.0E0_nag_wp) Then
            Write (nout,99993) x, '+Infinity'
          Else
            Write (nout,99993) x, '-Infinity'
          End If
        Case (9)
          Write (nout,99993) x, 'NaN'
        Case Default
          Write (nout,*) 'Illegal parameter: ifail = ', ifail
          Go To 100
        End Select
      End Do

100   Continue

99999 Format (12X,'a',14X,'b',14X,'c')
99998 Format (3('+--------------'),'+')
99997 Format (3(4X,F10.2,1X))
99996 Format (12X,'x',4X,'2F1(a,b;c;x)')
99995 Format (2('+--------------'),'+')
99994 Format (4X,F10.2,5X,F10.4)
99993 Format (4X,F10.2,3X,A13)
    End Program s22befe