Package pal.statistics
Class GammaDistribution
java.lang.Object
pal.statistics.GammaDistribution
- Direct Known Subclasses:
ChiSquareDistribution
,ExponentialDistribution
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
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic double
cdf
(double x, double shape, double scale) cumulative density function of the Gamma distributionstatic double
mean
(double shape, double scale) mean of the Gamma distributionstatic double
pdf
(double x, double shape, double scale) probability density function of the Gamma distributionstatic double
quantile
(double y, double shape, double scale) quantile (inverse cumulative density function) of the Gamma distributionstatic double
variance
(double shape, double scale) variance of the Gamma distribution
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Constructor Details
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GammaDistribution
public GammaDistribution()
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Method Details
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pdf
public static double pdf(double x, double shape, double scale) probability density function of the Gamma distribution- Parameters:
x
- argumentshape
- shape parameterscale
- scale parameter- Returns:
- pdf value
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cdf
public static double cdf(double x, double shape, double scale) cumulative density function of the Gamma distribution- Parameters:
x
- argumentshape
- shape parameterscale
- scale parameter- Returns:
- cdf value
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quantile
public static double quantile(double y, double shape, double scale) quantile (inverse cumulative density function) of the Gamma distribution- Parameters:
y
- argumentshape
- shape parameterscale
- scale parameter- Returns:
- icdf value
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mean
public static double mean(double shape, double scale) mean of the Gamma distribution- Parameters:
shape
- shape parameterscale
- scale parameter- Returns:
- mean
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variance
public static double variance(double shape, double scale) variance of the Gamma distribution- Parameters:
shape
- shape parameterscale
- scale parameter- Returns:
- variance
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