anchor.diff:       &                   a2 = 17.43,
        &                   md3 = 3.3d+09, 
        &                   a3 = 34.86,
  -     &                   g = 4.30026e-6
  +     &                   g = 4.30026e-6,
  +C                        TODO: take this out
  +     &                   METERS_IN_PARSEC = 3.086e+16
   
         real :: xcar, 
        &        ycar, 
  
positive.code:           ycar = ypla(wd_index)
  C         TODO: find out the meaning of wo and 8.0
            wo = ww(wd_index) + 8.0
  C         TODO: find out the meaning of zo and 3.086e+16
            zo = real(coordinate_Zcylindr(wd_index) * (3.086e+16))
  C         TODO: find out the meaning of ecini
            ecini = 0.5 * wo * wo
            call epot(zo, epoti)
  
negative.code:       xpla = xcar
        ypla = ycar
        zsig = z_coordinate
        z_coordinate = abs(z_coordinate) / METERS_IN_PARSEC
        rpla2 = xpla * xpla + ypla * ypla
        rpla = sqrt(rpla2)
        r2 = rpla * rpla + z_coordinate * z_coordinate
  