anchor.diff:      S%U = - sin_2_beta * RLS2 + cos_2_beta * RLS3
       S%V = RLS4
   
  -    a = a_final
  -
     end subroutine scatter_stokes
   
     elemental real(dp) function B_nu(nu,T)
  
positive.code:        P2 = interp2d(d%mu,d%nu,d%P2,a_scat%cost,nu)
         P3 = interp2d(d%mu,d%nu,d%P3,a_scat%cost,nu)
         P4 = interp2d(d%mu,d%nu,d%P4,a_scat%cost,nu)
         call scatter_stokes(s,a,a_scat,P1,P2,P3,P4)
      end if
      a = a_req
    end subroutine dust_scatter_peeloff
  
negative.code: 
      end if
  
      call rotate_angle3d(a_scat,a,a_final)
  
      ! Compute how the stokes parameters are changed by the interaction
      call scatter_stokes(s,a,a_scat,a_final,P1,P2,P3,P4) 
  
      norm = 1._dp / S%I
  
  