org.apache.commons.math4.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
• 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

All 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.math4.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)
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)
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.