com.numericalmethod.suanshu.analysis.function.special.gamma

Class LogGamma

java.lang.Object

com.numericalmethod.suanshu.analysis.function.rn2r1.univariate.UnivariateRealFunction

com.numericalmethod.suanshu.analysis.function.special.gamma.LogGamma

All Implemented Interfaces:

Function<Vector,java.lang.Double>, RealScalarFunction, java.io.Serializable

public class LogGamma
extends UnivariateRealFunction

The log-Gamma function, \(\log (\Gamma(z))\), for positive real numbers, is the log of the Gamma function.

See Also:

• Wikipedia: Gamma function
• Wikipedia: Lanczos approximation

, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LogGamma.Method the methods available to compute \(\log (\Gamma(z))\)

Nested classes/interfaces inherited from interface com.numericalmethod.suanshu.analysis.function.Function

Function.EvaluationException

Constructor Summary

Constructors

Constructor and Description
LogGamma() Construct an instance of log-Gamma.
LogGamma(LogGamma.Method method, Lanczos lanczos) Construct an instance of log-Gamma.

Method Summary

Modifier and Type	Method and Description
double	evaluate(double x) Evaluate the log of the Gamma function in the positive real domain.

Methods inherited from class com.numericalmethod.suanshu.analysis.function.rn2r1.univariate.UnivariateRealFunction

dimensionOfDomain, dimensionOfRange, evaluate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LogGamma

public LogGamma(LogGamma.Method method,
                Lanczos lanczos)

Construct an instance of log-Gamma.

Parameters:

method - the Lanczos computation to use

lanczos - the Lanczos approximation to use

LogGamma

public LogGamma()

Construct an instance of log-Gamma.

Method Detail

evaluate

public double evaluate(double x)

Evaluate the log of the Gamma function in the positive real domain.

Specified by:

evaluate in class UnivariateRealFunction

Parameters:

x - a real number > 0

Returns:

\(\log (\Gamma(z))\)