Class GaussIntegrator

    • Constructor Detail

      • GaussIntegrator

        public GaussIntegrator​(double[] points,
                               double[] weights)
                        throws MathIllegalArgumentException
        Creates an integrator from the given points and weights. The integration interval is defined by the first and last value of points which must be sorted in increasing order.
        Parameters:
        points - Integration points.
        weights - Weights of the corresponding integration nodes.
        Throws:
        MathIllegalArgumentException - if the points are not sorted in increasing order.
        MathIllegalArgumentException - if points and weights don't have the same length
    • Method Detail

      • integrate

        public double integrate​(UnivariateFunction f)
        Returns an estimate of the integral of f(x) * w(x), where w is a weight function that depends on the actual flavor of the Gauss integration scheme. The algorithm uses the points and associated weights, as passed to the constructor.
        Parameters:
        f - Function to integrate.
        Returns:
        the integral of the weighted function.
      • getNumberOfPoints

        public int getNumberOfPoints()
        Get the order of the integration rule.
        Returns:
        the order of the integration rule (the number of integration points).
      • getPoint

        public double getPoint​(int index)
        Gets the integration point at the given index. The index must be in the valid range but no check is performed.
        Parameters:
        index - index of the integration point
        Returns:
        the integration point.
      • getWeight

        public double getWeight​(int index)
        Gets the weight of the integration point at the given index. The index must be in the valid range but no check is performed.
        Parameters:
        index - index of the integration point
        Returns:
        the weight.