!-------------------------------------- LICENCE BEGIN ------------------------------------
!Environment Canada - Atmospheric Science and Technology License/Disclaimer,
!                     version 3; Last Modified: May 7, 2008.
!This is free but copyrighted software; you can use/redistribute/modify it under the terms
!of the Environment Canada - Atmospheric Science and Technology License/Disclaimer
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!This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
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!See the above mentioned License/Disclaimer for more details.
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!-------------------------------------- LICENCE END --------------------------------------
!

      subroutine cft8( r, a, inc, jump, lot, n ) 2

C
      implicit none
#include "taglam4d.cdk"
C
      integer inc, jump, lot, n
      real*8  r(*), a(*)
C
      integer i, j, k
C
      real*8 zero, half, one, two
      parameter( zero = 0.0 )
      parameter( half = 0.5 )
      parameter( one  = 1.0 )
      parameter( two  = 2.0 )

      real*8 cnorm, del, angle, cc, cnorm2, faz
      integer ij
      ij(i,j) = 1 + ( j - 1 ) * jump + i * inc

      cnorm = sqrt( two/n )
      cnorm2 = sqrt( one/(2*n) )
      del   = acos( - one )/n
C
C     The transform  is along the i-th direction
C     and the indexing is 1+(j-1)*jump+i*inc (i=0,n,j=1,lot)
C     in the input & output fields
C
      faz = - one
      do k=0,n
         faz = - faz

         do j=1,lot
            r( ij(k,j) ) = cnorm2 * ( a( ij(0,j) )
     %                                  + faz * a( ij(n,j) ) )
         enddo

         do i=1,n-1

            angle = k * i * del
            cc = cnorm * cos( angle )

            do j=1,lot
               r( ij(k,j) ) = r( ij(k,j) ) + cc * a( ij(i,j) )
            enddo

         enddo

      enddo
         
      return
      end