GammaDistribution

java.lang.Object
- pal.statistics.GammaDistribution

Direct Known Subclasses:

ChiSquareDistribution, ExponentialDistribution
```
public class GammaDistribution
extends java.lang.Object
```
gamma distribution. (Parameters: shape, scale; mean: scale*shape; variance: scale^2*shape)

Version:

$Id: GammaDistribution.java,v 1.3 2001/07/13 14:39:13 korbinian Exp $

Author:

Korbinian Strimmer

Constructor Summary

Constructors
Constructor Description

GammaDistribution()

Constructors
Constructor	Description
`GammaDistribution()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static double`	`cdf(double x, double shape, double scale)`	cumulative density function of the Gamma distribution
`static double`	`mean(double shape, double scale)`	mean of the Gamma distribution
`static double`	`pdf(double x, double shape, double scale)`	probability density function of the Gamma distribution
`static double`	`quantile(double y, double shape, double scale)`	quantile (inverse cumulative density function) of the Gamma distribution
`static double`	`variance(double shape, double scale)`	variance of the Gamma distribution

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - GammaDistribution
```
public GammaDistribution()
```
- Method Detail
  - pdf
```
public static double pdf(double x,
                         double shape,
                         double scale)
```
    probability density function of the Gamma distribution
    
    Parameters:
    
    x - argument
    
    shape - shape parameter
    
    scale - scale parameter
    
    Returns:
    
    pdf value
  - cdf
```
public static double cdf(double x,
                         double shape,
                         double scale)
```
    cumulative density function of the Gamma distribution
    
    Parameters:
    
    x - argument
    
    shape - shape parameter
    
    scale - scale parameter
    
    Returns:
    
    cdf value
  - quantile
```
public static double quantile(double y,
                              double shape,
                              double scale)
```
    quantile (inverse cumulative density function) of the Gamma distribution
    
    Parameters:
    
    y - argument
    
    shape - shape parameter
    
    scale - scale parameter
    
    Returns:
    
    icdf value
  - mean
```
public static double mean(double shape,
                          double scale)
```
    mean of the Gamma distribution
    
    Parameters:
    
    shape - shape parameter
    
    scale - scale parameter
    
    Returns:
    
    mean
  - variance
```
public static double variance(double shape,
                              double scale)
```
    variance of the Gamma distribution
    
    Parameters:
    
    shape - shape parameter
    
    scale - scale parameter
    
    Returns:
    
    variance

Class GammaDistribution

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

GammaDistribution

Method Detail

pdf

cdf

quantile

mean

variance