@Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((algorithm == null) ? 0 : algorithm.hashCode());
        result = prime * result + ((scheme == null) ? 0 : scheme.hashCode());
        long temp;
        temp = Double.doubleToLongBits(rmax);
        result = prime * result + (int) (temp ^ (temp >>> 32));
        temp = Double.doubleToLongBits(rmin);
        result = prime * result + (int) (temp ^ (temp >>> 32));
        temp = Double.doubleToLongBits(imax);
        result = prime * result + (int) (temp ^ (temp >>> 32));
        temp = Double.doubleToLongBits(imin);
        result = prime * result + (int) (temp ^ (temp >>> 32));
        return result;
    }