org.apache.commons.math3.analysis.integration.gauss

## Class SymmetricGaussIntegrator

• public class SymmetricGaussIntegrator
extends GaussIntegrator
This class's implements integrate method assuming that the integral is symmetric about 0. This allows to reduce numerical errors.
Since:
3.3
Version:
$Id: SymmetricGaussIntegrator.html 908881 2014-05-15 07:10:28Z luc$
• ### Constructor Summary

Constructors
Constructor and Description
SymmetricGaussIntegrator(double[] points, double[] weights)
Creates an integrator from the given points and weights.
SymmetricGaussIntegrator(Pair<double[],double[]> pointsAndWeights)
Creates an integrator from the given pair of points (first element of the pair) and weights (second element of the pair.
• ### Method Summary

Methods
Modifier and Type Method and Description
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.
• ### Methods inherited from class org.apache.commons.math3.analysis.integration.gauss.GaussIntegrator

getNumberOfPoints, getPoint, getWeight
• ### Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
• ### Constructor Detail

• #### SymmetricGaussIntegrator

public SymmetricGaussIntegrator(double[] points,
double[] weights)
throws NonMonotonicSequenceException,
DimensionMismatchException
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:
NonMonotonicSequenceException - if the points are not sorted in increasing order.
DimensionMismatchException - if points and weights don't have the same length
• #### SymmetricGaussIntegrator

public SymmetricGaussIntegrator(Pair<double[],double[]> pointsAndWeights)
throws NonMonotonicSequenceException
Creates an integrator from the given pair of points (first element of the pair) and weights (second element of the pair.
Parameters:
pointsAndWeights - Integration points and corresponding weights.
Throws:
NonMonotonicSequenceException - if the points are not sorted in increasing order.
SymmetricGaussIntegrator(double[], double[])
• ### 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.
Overrides:
integrate in class GaussIntegrator
Parameters:
f - Function to integrate.
Returns:
the integral of the weighted function.