Program c06pcfe

!     C06PCF Example Program Text

!     Mark 28.3 Release. NAG Copyright 2022.

!     .. Use Statements ..
      Use nag_library, Only: c06pcf, nag_wp
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
      Integer                          :: ieof, ifail, j, n
!     .. Local Arrays ..
      Complex (Kind=nag_wp), Allocatable :: work(:), x(:), xx(:)
!     .. Executable Statements ..
      Write (nout,*) 'C06PCF Example Program Results'
!     Skip heading in data file
      Read (nin,*)
loop: Do
        Read (nin,*,Iostat=ieof) n
        If (ieof<0) Then
          Exit loop
        End If

        Allocate (work(2*n+15),x(0:n-1),xx(0:n-1))
        Read (nin,*) x(0:n-1)
        xx(0:n-1) = x(0:n-1)

!       ifail: behaviour on error exit
!              =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
        ifail = 0
        Call c06pcf('F',x,n,work,ifail)

        Write (nout,*)
        Write (nout,*) 'Components of discrete Fourier transform'
        Write (nout,*)
        Write (nout,*) '              Real      Imag'
        Write (nout,*)
        Do j = 0, n - 1
          Write (nout,99999) j, x(j)
        End Do

        Call c06pcf('B',x,n,work,ifail)

        Write (nout,*)
        Write (nout,*) 'Original sequence as restored by inverse transform'
        Write (nout,*)
        Write (nout,*) '                 Original                 Restored'
        Write (nout,*) '              Real      Imag           Real      Imag'
        Write (nout,*)
        Do j = 0, n - 1
          Write (nout,99999) j, xx(j), x(j)
        End Do
        Deallocate (work,x,xx)
      End Do loop

99999 Format (1X,I5,2(:,5X,'(',F8.5,',',F8.5,')'))
    End Program c06pcfe