Program g13awfe
!     G13AWF Example Program Text

!     Mark 27.3 Release. NAG Copyright 2021.

!     .. Use Statements ..
      Use nag_library, Only: g01ewf, g13awf, nag_wp
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
      Real (Kind=nag_wp)               :: pvalue, ts
      Integer                          :: ifail, method, n, nsamp, p, type
!     .. Local Arrays ..
      Real (Kind=nag_wp), Allocatable  :: y(:)
      Integer                          :: state(1)
!     .. Executable Statements ..

      Write (nout,*) 'G13AWF Example Program Results'
      Write (nout,*)

!     Skip heading in data file
      Read (nin,*)

!     Read in the problem size, test type, order of the AR process
      Read (nin,*) n, type, p

!     Allocate memory
      Allocate (y(n))

!     Read in the time series
      Read (nin,*) y(1:n)

!     Calculate the Dickey-Fuller test statistic
      ifail = 0
      ts = g13awf(type,p,n,y,ifail)

!     Get the associated p-value using the look-up method
      method = 1
      ifail = -1
      pvalue = g01ewf(method,type,n,ts,nsamp,state,ifail)

      If (ifail==0 .Or. ifail==201) Then
!       Display the results
        Write (nout,'(A,F6.3)') 'Dickey-Fuller test statistic     = ', ts
        Write (nout,'(A,F6.3)') 'associated p-value               = ', pvalue
      End If

    End Program g13awfe