public static final class RegularizedGamma.P extends Object
\[ P(a,x) = 1 - Q(a,x) = \frac{\gamma(a,x)}{\Gamma(a)} = \frac{1}{\Gamma(a)} \int_0^x t^{a-1}\,e^{-t}\,dt \]
Modifier and Type | Method and Description |
---|---|
static double |
derivative(double a,
double x)
Computes the derivative of the lower regularized gamma function \( P(a, x) \).
|
static double |
value(double a,
double x)
Computes the lower regularized gamma function \( P(a, x) \).
|
static double |
value(double a,
double x,
double epsilon,
int maxIterations)
Computes the lower regularized gamma function \( P(a, x) \).
|
public static double value(double a, double x)
a
- Argument.x
- Argument.ArithmeticException
- if the continued fraction fails to converge.public static double value(double a, double x, double epsilon, int maxIterations)
a
- Argument.x
- Argument.epsilon
- Tolerance in series evaluation.maxIterations
- Maximum number of iterations in series evaluation.ArithmeticException
- if the series evaluation fails to converge.public static double derivative(double a, double x)
\[ \frac{\delta}{\delta x} P(a,x) = \frac{e^{-x} x^{a-1}}{\Gamma(a)} \]
This function has uses in some statistical distributions.
a
- Argument.x
- Argument.Copyright © 2017–2022 The Apache Software Foundation. All rights reserved.