@Override
  public double[] getNodeSensitivitiesForValue(
      final Interpolator1DDataBundle data, final Double value) {

    final double yStar = _base.interpolate(data, value);
    final double grad = _transform.inverseTransformGradient(yStar);
    final double[] temp = _base.getNodeSensitivitiesForValue(data, value);

    final int n = temp.length;
    for (int i = 0; i < n; i++) {
      temp[i] *= grad;
    }
    return temp;
  }
 @Override
 public double firstDerivative(final Interpolator1DDataBundle data, final Double value) {
   return _transform.inverseTransformGradient(_base.interpolate(data, value))
       * _base.firstDerivative(data, value);
 }