private void CalculatePoint(object cell_pos_seeds)
    {
        List <object> param = (List <object>)cell_pos_seeds;

        int[]    cell = (int[])param[0];
        double[] pos  = (double[])param[1];
        List <Seed_DEPRECATED> seeds = (List <Seed_DEPRECATED>)param[2];

        double FTLE = Interpolator_DEPRECATED.IWDInterpolateFTLE(pos, seeds, 0.5);

        lock (fieldlock)
        {
            field[cell[0], cell[1]] = FTLE;
        }
        notifier.Set();
    }