/*! \pre the \f$ x \f$ values must be sorted. */

        public LogCubicInterpolation(List <double> xBegin, int size, List <double> yBegin,
                                     CubicInterpolation.DerivativeApprox da,
                                     bool monotonic,
                                     CubicInterpolation.BoundaryCondition leftC,
                                     double leftConditionValue,
                                     CubicInterpolation.BoundaryCondition rightC,
                                     double rightConditionValue)
        {
            impl_ = new LogInterpolationImpl <Cubic>(xBegin, size, yBegin,
                                                     new Cubic(da, monotonic, leftC, leftConditionValue, rightC, rightConditionValue));
            impl_.update();
        }
        /*! \pre the \f$ x \f$ values must be sorted. */

        public LogLinearInterpolation(List <double> xBegin, int size, List <double> yBegin)
        {
            impl_ = new LogInterpolationImpl <Linear>(xBegin, size, yBegin);
            impl_.update();
        }