java.lang.Object
- cern.colt.PersistentObject
- - cern.jet.random.AbstractDistribution
  - - cern.jet.random.AbstractDiscreteDistribution
    - - cern.jet.random.HyperGeometric

All Implemented Interfaces:

DoubleFunction, IntFunction, java.io.Serializable, java.lang.Cloneable
```
public class HyperGeometric
extends AbstractDiscreteDistribution
```
HyperGeometric distribution; See the math definition The hypergeometric distribution with parameters N, n and s is the probability distribution of the random variable X, whose value is the number of successes in a sample of n items from a population of size N that has s 'success' items and N - s 'failure' items.
p(k) = C(s,k) * C(N-s,n-k) / C(N,n) where C(a,b) = a! / (b! * (a-b)!).
valid for N >= 2, s,n <= N.
Instance methods operate on a user supplied uniform random number generator; they are unsynchronized.
Static methods operate on a default uniform random number generator; they are synchronized.
Implementation: High performance implementation. Patchwork Rejection/Inversion method.
This is a port of hprsc.c from the C-RAND / WIN-RAND library. C-RAND's implementation, in turn, is based upon
H. Zechner (1994): Efficient sampling from continuous and discrete unimodal distributions, Doctoral Dissertation, 156 pp., Technical University Graz, Austria.

Version:

1.0, 09/24/99

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type	Field	Description
`private int`	`b`
`private double`	`c_pm`
`private double`	`dl`
`private double`	`dr`
`private double`	`f1`
`private double`	`f2`
`private double`	`f4`
`private double`	`f5`
`private double`	`fm`
`private int`	`k1`
`private int`	`k2`
`private int`	`k4`
`private int`	`k5`
`private double`	`ll`
`private double`	`lr`
`private int`	`m`
`private int`	`M_last`
`private int`	`mp`
`private double`	`Mp`
`protected int`	`my_n`
`protected int`	`my_N`
`protected int`	`my_s`
`private int`	`n_last`
`private int`	`N_last`
`private int`	`N_Mn`
`private double`	`np`
`private double`	`p1`
`private double`	`p2`
`private double`	`p3`
`private double`	`p4`
`private double`	`p5`
`private double`	`p6`
`private double`	`r1`
`private double`	`r2`
`private double`	`r4`
`private double`	`r5`
`protected static HyperGeometric`	`shared`

Fields inherited from class cern.jet.random.AbstractDistribution
randomGenerator

Fields inherited from class cern.colt.PersistentObject
serialVersionUID

Constructor Summary

Constructors
Constructor	Description
`HyperGeometric(int N, int s, int n, RandomEngine randomGenerator)`	Constructs a HyperGeometric distribution.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`private static double`	`fc_lnpk(int k, int N_Mn, int M, int n)`
`protected int`	`hmdu(int N, int M, int n, RandomEngine randomGenerator)`	Returns a random number from the distribution.
`protected int`	`hprs(int N, int M, int n, RandomEngine randomGenerator)`	Returns a random number from the distribution.
`int`	`nextInt()`	Returns a random number from the distribution.
`int`	`nextInt(int N, int s, int n)`	Returns a random number from the distribution; bypasses the internal state.
`protected int`	`nextInt(int N, int M, int n, RandomEngine randomGenerator)`	Returns a random number from the distribution; bypasses the internal state.
`double`	`pdf(int k)`	Returns the probability distribution function.
`void`	`setState(int N, int s, int n)`	Sets the parameters.
`static double`	`staticNextInt(int N, int M, int n)`	Returns a random number from the distribution.
`java.lang.String`	`toString()`	Returns a String representation of the receiver.
`private static void`	`xstaticSetRandomGenerator(RandomEngine randomGenerator)`	Sets the uniform random number generated shared by all static methods.

Methods inherited from class cern.jet.random.AbstractDiscreteDistribution
nextDouble

Methods inherited from class cern.jet.random.AbstractDistribution
apply, apply, clone, getRandomGenerator, makeDefaultGenerator, setRandomGenerator

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

Field Detail

my_N
```
protected int my_N
```

my_s
```
protected int my_s
```

my_n
```
protected int my_n
```

N_last
```
private int N_last
```

M_last
```
private int M_last
```

n_last
```
private int n_last
```

N_Mn
```
private int N_Mn
```

m
```
private int m
```

mp
```
private int mp
```

b
```
private int b
```

Mp
```
private double Mp
```

np
```
private double np
```

fm
```
private double fm
```

k2
```
private int k2
```

k4
```
private int k4
```

k1
```
private int k1
```

k5
```
private int k5
```

dl
```
private double dl
```

dr
```
private double dr
```

r1
```
private double r1
```

r2
```
private double r2
```

r4
```
private double r4
```

r5
```
private double r5
```

ll
```
private double ll
```

lr
```
private double lr
```

c_pm
```
private double c_pm
```

f1
```
private double f1
```

f2
```
private double f2
```

f4
```
private double f4
```

f5
```
private double f5
```

p1
```
private double p1
```

p2
```
private double p2
```

p3
```
private double p3
```

p4
```
private double p4
```

p5
```
private double p5
```

p6
```
private double p6
```

shared
```
protected static HyperGeometric shared
```

Constructor Detail

HyperGeometric

public HyperGeometric(int N,
                      int s,
                      int n,
                      RandomEngine randomGenerator)

Constructs a HyperGeometric distribution.

Method Detail

fc_lnpk

private static double fc_lnpk(int k,
                              int N_Mn,
                              int M,
                              int n)

hmdu

protected int hmdu(int N,
                   int M,
                   int n,
                   RandomEngine randomGenerator)

Returns a random number from the distribution.

hprs

protected int hprs(int N,
                   int M,
                   int n,
                   RandomEngine randomGenerator)

Returns a random number from the distribution.

nextInt
```
public int nextInt()
```
Returns a random number from the distribution.

Specified by:

nextInt in class AbstractDiscreteDistribution

nextInt

public int nextInt(int N,
                   int s,
                   int n)

Returns a random number from the distribution; bypasses the internal state.

nextInt

protected int nextInt(int N,
                      int M,
                      int n,
                      RandomEngine randomGenerator)

Returns a random number from the distribution; bypasses the internal state.

pdf
```
public double pdf(int k)
```
Returns the probability distribution function.

setState

public void setState(int N,
                     int s,
                     int n)

Sets the parameters.

staticNextInt

public static double staticNextInt(int N,
                                   int M,
                                   int n)

Returns a random number from the distribution.

toString
```
public java.lang.String toString()
```
Returns a String representation of the receiver.

Overrides:

toString in class java.lang.Object

xstaticSetRandomGenerator
```
private static void xstaticSetRandomGenerator(RandomEngine randomGenerator)
```
Sets the uniform random number generated shared by all static methods.

Parameters:

randomGenerator - the new uniform random number generator to be shared.

Class HyperGeometric

Field Summary

Fields inherited from class cern.jet.random.AbstractDistribution

Fields inherited from class cern.colt.PersistentObject

Constructor Summary

Method Summary

Methods inherited from class cern.jet.random.AbstractDiscreteDistribution

Methods inherited from class cern.jet.random.AbstractDistribution

Methods inherited from class java.lang.Object

Field Detail

my_N

my_s

my_n

N_last

M_last

n_last

N_Mn

m

mp

b

Mp

np

fm

k2

k4

k1

k5

dl

dr

r1

r2

r4

r5

ll

lr

c_pm

f1

f2

f4

f5

p1

p2

p3

p4

p5

p6

shared

Constructor Detail

HyperGeometric

Method Detail

fc_lnpk

hmdu

hprs

nextInt

nextInt

nextInt

pdf

setState

staticNextInt

toString

xstaticSetRandomGenerator