class Interpolator1DDoubleQuadraticDataBundle implements Interpolator1DDataBundle, Serializable {

  private RealPolynomialFunction1D getQuadratic(final double[] x, final double[] y, final int index) {
    final double a = y[index];
    final double dx1 = x[index] - x[index - 1];
    final double dx2 = x[index + 1] - x[index];
    final double dy1 = y[index] - y[index - 1];
    final double dy2 = y[index + 1] - y[index];
    final double b = (dx1 * dy2 / dx2 + dx2 * dy1 / dx1) / (dx1 + dx2);
    final double c = (dy2 / dx2 - dy1 / dx1) / (dx1 + dx2);
    return new RealPolynomialFunction1D(new double[] {a, b, c });
  }

  public  Interpolator1DDoubleQuadraticDataBundle(final Interpolator1DDataBundle underlyingData);

}