com.numericalmethod.suanshu.analysis.function.special
Class GammaLowerIncomplete

java.lang.Object
  com.numericalmethod.suanshu.analysis.function.rn2r1.BivariateRealFunction
      com.numericalmethod.suanshu.analysis.function.special.GammaLowerIncomplete

All Implemented Interfaces:

Function, RealScalarFunction

public class GammaLowerIncomplete
extends BivariateRealFunction

This computes an approximation to the Lower Incomplete Gamma function, γ(s, x).

The integrand has the same form as the Gamma function, but the upper limit of the integration is a variable. The lower limit is fixed.

       x
       /
 γ(s, x)= | ts-1e-t dt = P(s, x) * Γ(s)
       /
       0
 

See Also:

Wikipedia: Incomplete gamma function

Nested Class Summary

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

Function.EvaluationException

Constructor Summary

GammaLowerIncomplete()

Method Summary

double

evaluate(double s, double x) Evaluate γ(s, x).

Methods inherited from class com.numericalmethod.suanshu.analysis.function.rn2r1.BivariateRealFunction

dimension4Domain, dimension4Range, evaluate

Methods inherited from class java.lang.Object

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

Constructor Detail

GammaLowerIncomplete

public GammaLowerIncomplete()

Method Detail

evaluate

public double evaluate(double s,
                       double x)

Evaluate γ(s, x).

Specified by:

evaluate in class BivariateRealFunction

Parameters:

s - s > 0

x - x ≥ 0

Returns:

γ(s, x)