Class GaussIntegrator
java.lang.Object
org.hipparchus.analysis.integration.gauss.GaussIntegrator
- Direct Known Subclasses:
SymmetricGaussIntegrator
Class that implements the Gaussian rule for
integrating
a weighted
function.-
Constructor Summary
ConstructorDescriptionGaussIntegrator
(double[] points, double[] weights) Creates an integrator from the givenpoints
andweights
.GaussIntegrator
(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
Modifier and TypeMethodDescriptionint
Get the order of the integration rule.double
getPoint
(int index) Gets the integration point at the given index.double
getWeight
(int index) Gets the weight of the integration point at the given index.double
Returns an estimate of the integral off(x) * w(x)
, wherew
is a weight function that depends on the actual flavor of the Gauss integration scheme.
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Constructor Details
-
GaussIntegrator
Creates an integrator from the givenpoints
andweights
. The integration interval is defined by the first and last value ofpoints
which must be sorted in increasing order.- Parameters:
points
- Integration points.weights
- Weights of the corresponding integration nodes.- Throws:
MathIllegalArgumentException
- if thepoints
are not sorted in increasing order.MathIllegalArgumentException
- if points and weights don't have the same length
-
GaussIntegrator
public GaussIntegrator(Pair<double[], double[]> pointsAndWeights) throws MathIllegalArgumentExceptionCreates 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:
MathIllegalArgumentException
- if thepoints
are not sorted in increasing order.- See Also:
-
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Method Details
-
integrate
Returns an estimate of the integral off(x) * w(x)
, wherew
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 theconstructor
.- Parameters:
f
- Function to integrate.- Returns:
- the integral of the weighted function.
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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.
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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.
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