Class ChiDistribution
- java.lang.Object
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- elki.math.statistics.distribution.ChiDistribution
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- All Implemented Interfaces:
Distribution
public class ChiDistribution extends java.lang.Object implements Distribution
Chi distribution.- Since:
- 0.5.0
- Author:
- Erich Schubert
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ChiDistribution.Par
Parameterization class-
Nested classes/interfaces inherited from interface elki.math.statistics.distribution.Distribution
Distribution.Parameterizer
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Field Summary
Fields Modifier and Type Field Description private ChiSquaredDistribution
chisq
Chi squared distribution (for random generation)private double
dof
Degrees of freedom.
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Constructor Summary
Constructors Constructor Description ChiDistribution(double dof)
Constructor.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description double
cdf(double val)
Return the cumulative density function at the given value.static double
cdf(double val, double dof)
Cumulative density function.double
logpdf(double val)
Return the log density of an existing valuestatic double
logpdf(double val, double dof)
logPDF functiondouble
nextRandom(java.util.Random random)
Generate a new random valuedouble
pdf(double val)
Return the density of an existing valuestatic double
pdf(double val, double dof)
PDF functiondouble
quantile(double val)
Quantile aka probit (for normal) aka inverse CDF (invcdf, cdf^-1) function.java.lang.String
toString()
Describe the distribution
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Field Detail
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dof
private double dof
Degrees of freedom. Usually integer.
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chisq
private ChiSquaredDistribution chisq
Chi squared distribution (for random generation)
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Method Detail
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nextRandom
public double nextRandom(java.util.Random random)
Description copied from interface:Distribution
Generate a new random value- Specified by:
nextRandom
in interfaceDistribution
- Parameters:
random
- Random number generator- Returns:
- new random value
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pdf
public double pdf(double val)
Description copied from interface:Distribution
Return the density of an existing value- Specified by:
pdf
in interfaceDistribution
- Parameters:
val
- existing value- Returns:
- distribution density
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pdf
public static double pdf(double val, double dof)
PDF function- Parameters:
val
- Valuedof
- Degrees of freedom- Returns:
- Pdf value
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logpdf
public double logpdf(double val)
Description copied from interface:Distribution
Return the log density of an existing value- Specified by:
logpdf
in interfaceDistribution
- Parameters:
val
- existing value- Returns:
- log distribution density
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logpdf
public static double logpdf(double val, double dof)
logPDF function- Parameters:
val
- Valuedof
- Degrees of freedom- Returns:
- logPdf value
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cdf
public double cdf(double val)
Description copied from interface:Distribution
Return the cumulative density function at the given value.- Specified by:
cdf
in interfaceDistribution
- Parameters:
val
- existing value- Returns:
- cumulative density
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cdf
public static double cdf(double val, double dof)
Cumulative density function.- Parameters:
val
- Valuedof
- Degrees of freedom.- Returns:
- CDF value
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quantile
public double quantile(double val)
Description copied from interface:Distribution
Quantile aka probit (for normal) aka inverse CDF (invcdf, cdf^-1) function.- Specified by:
quantile
in interfaceDistribution
- Parameters:
val
- Quantile to find- Returns:
- Quantile position
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toString
public java.lang.String toString()
Description copied from interface:Distribution
Describe the distribution- Specified by:
toString
in interfaceDistribution
- Overrides:
toString
in classjava.lang.Object
- Returns:
- description
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