radb3 Subroutine

      subroutine radb3(Ido,l1,Cc,Ch,Wa1,Wa2)
      use fftpack_kind
      implicit none
      real(rk) :: Cc , Ch , ci2 , ci3 , cr2 , cr3 , di2 , di3 , &
                  dr2 , dr3 , ti2 , tr2 , Wa1 , Wa2
      integer :: i , ic , Ido , idp2 , k , l1
      dimension Cc(Ido,3,l1) , Ch(Ido,l1,3) , Wa1(*) , Wa2(*)
      real(rk),parameter :: taur = - 0.5_rk
      real(rk),parameter :: taui = sqrt(3.0_rk) / 2.0_rk
      do k = 1 , l1
         tr2 = Cc(Ido,2,k) + Cc(Ido,2,k)
         cr2 = Cc(1,1,k) + taur*tr2
         Ch(1,k,1) = Cc(1,1,k) + tr2
         ci3 = taui*(Cc(1,3,k)+Cc(1,3,k))
         Ch(1,k,2) = cr2 - ci3
         Ch(1,k,3) = cr2 + ci3
      enddo
      if ( Ido==1 ) return
      idp2 = Ido + 2
      do k = 1 , l1
         do i = 3 , Ido , 2
            ic = idp2 - i
            tr2 = Cc(i-1,3,k) + Cc(ic-1,2,k)
            cr2 = Cc(i-1,1,k) + taur*tr2
            Ch(i-1,k,1) = Cc(i-1,1,k) + tr2
            ti2 = Cc(i,3,k) - Cc(ic,2,k)
            ci2 = Cc(i,1,k) + taur*ti2
            Ch(i,k,1) = Cc(i,1,k) + ti2
            cr3 = taui*(Cc(i-1,3,k)-Cc(ic-1,2,k))
            ci3 = taui*(Cc(i,3,k)+Cc(ic,2,k))
            dr2 = cr2 - ci3
            dr3 = cr2 + ci3
            di2 = ci2 + cr3
            di3 = ci2 - cr3
            Ch(i-1,k,2) = Wa1(i-2)*dr2 - Wa1(i-1)*di2
            Ch(i,k,2) = Wa1(i-2)*di2 + Wa1(i-1)*dr2
            Ch(i-1,k,3) = Wa2(i-2)*dr3 - Wa2(i-1)*di3
            Ch(i,k,3) = Wa2(i-2)*di3 + Wa2(i-1)*dr3
         enddo
      enddo
      end subroutine radb3