Package org.hipparchus.util
Class ContinuedFraction
java.lang.Object
org.hipparchus.util.ContinuedFraction
Provides a generic means to evaluate continued fractions. Subclasses simply
provided the a and b coefficients to evaluate the continued fraction.
References:
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptiondouble
evaluate
(double x) Evaluates the continued fraction at the value x.double
evaluate
(double x, double epsilon) Evaluates the continued fraction at the value x.double
evaluate
(double x, double epsilon, int maxIterations) Evaluates the continued fraction at the value x.double
evaluate
(double x, int maxIterations) Evaluates the continued fraction at the value x.protected abstract double
getA
(int n, double x) Access the n-th a coefficient of the continued fraction.protected abstract double
getB
(int n, double x) Access the n-th b coefficient of the continued fraction.
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Constructor Details
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ContinuedFraction
protected ContinuedFraction()Default constructor.
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Method Details
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getA
protected abstract double getA(int n, double x) Access the n-th a coefficient of the continued fraction. Since a can be a function of the evaluation point, x, that is passed in as well.- Parameters:
n
- the coefficient index to retrieve.x
- the evaluation point.- Returns:
- the n-th a coefficient.
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getB
protected abstract double getB(int n, double x) Access the n-th b coefficient of the continued fraction. Since b can be a function of the evaluation point, x, that is passed in as well.- Parameters:
n
- the coefficient index to retrieve.x
- the evaluation point.- Returns:
- the n-th b coefficient.
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evaluate
Evaluates the continued fraction at the value x.- Parameters:
x
- the evaluation point.- Returns:
- the value of the continued fraction evaluated at x.
- Throws:
MathIllegalStateException
- if the algorithm fails to converge.
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evaluate
Evaluates the continued fraction at the value x.- Parameters:
x
- the evaluation point.epsilon
- maximum error allowed.- Returns:
- the value of the continued fraction evaluated at x.
- Throws:
MathIllegalStateException
- if the algorithm fails to converge.
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evaluate
Evaluates the continued fraction at the value x.- Parameters:
x
- the evaluation point.maxIterations
- maximum number of convergents- Returns:
- the value of the continued fraction evaluated at x.
- Throws:
MathIllegalStateException
- if the algorithm fails to converge.MathIllegalStateException
- if maximal number of iterations is reached
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evaluate
public double evaluate(double x, double epsilon, int maxIterations) throws MathIllegalStateException Evaluates the continued fraction at the value x.The implementation of this method is based on the modified Lentz algorithm as described on page 18 ff. in:
- I. J. Thompson, A. R. Barnett. "Coulomb and Bessel Functions of Complex Arguments and Order." http://www.fresco.org.uk/papers/Thompson-JCP64p490.pdf
Note: the implementation uses the terms ai and bi as defined in Continued Fraction @ MathWorld.
- Parameters:
x
- the evaluation point.epsilon
- maximum error allowed.maxIterations
- maximum number of convergents- Returns:
- the value of the continued fraction evaluated at x.
- Throws:
MathIllegalStateException
- if the algorithm fails to converge.MathIllegalStateException
- if maximal number of iterations is reached
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