docs: @Override
    public double getWeight(double distance, double max, double stddev) {
      if(max <= 0) {
        return 1.0;
      }
      double relativedistance = distance / max;
      // -2.303 is log(.1) to suit the intended range of 1.0-0.1
      return FastMath.exp(-2.3025850929940455 * relativedistance * relativedistance);
    }