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

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

All Implemented Interfaces:

Function, RealScalarFunction

public class GammaUpperIncomplete
extends BivariateRealFunction

This computes an approximation to the Upper Incomplete Gamma function, Γ(s, x).

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

       ∞
       /
 Γ(s, x)= | ts-1e-t dt = Q(s, x) * Γ(s)
       /
       x
 

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

GammaUpperIncomplete()

Method Summary

double

evaluate(double s, double x) Compute 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

GammaUpperIncomplete

public GammaUpperIncomplete()

Method Detail

evaluate

public double evaluate(double s,
                       double x)

Compute Γ(s, x).

Specified by:

evaluate in class BivariateRealFunction

Parameters:

s - s > 0

x - x ≥ 0

Returns:

Γ(s, x)