public class NegativeBinomial extends AbstractDiscreteDistribution
Instance methods operate on a user supplied uniform random number generator; they are unsynchronized.
Implementation: High performance implementation. Compound method.
J.H. Ahrens, U. Dieter (1974): Computer methods for sampling from gamma, beta, Poisson and binomial distributions, Computing 12, 223--246.
Modifier and Type | Field and Description |
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protected Gamma |
gamma |
protected int |
n |
protected double |
p |
protected Poisson |
poisson |
randomGenerator
Constructor and Description |
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NegativeBinomial(int n,
double p,
MersenneTwisterFast randomGenerator)
Constructs a Negative Binomial distribution.
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Modifier and Type | Method and Description |
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double |
cdf(int k)
Returns the cumulative distribution function.
|
int |
nextInt()
Returns a random number from the distribution.
|
int |
nextInt(int n,
double p)
Returns a random number from the distribution; bypasses the internal state.
|
double |
pdf(int k)
Returns the probability distribution function.
|
void |
setNandP(int n,
double p)
Sets the parameters number of trials and the probability of success.
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java.lang.String |
toString()
Returns a String representation of the receiver.
|
nextDouble
apply, apply, getRandomGenerator, setRandomGenerator
protected int n
protected double p
protected Gamma gamma
protected Poisson poisson
public NegativeBinomial(int n, double p, MersenneTwisterFast randomGenerator)
n
- the number of trials.p
- the probability of success.randomGenerator
- a uniform random number generator.public double cdf(int k)
public int nextInt()
nextInt
in class AbstractDiscreteDistribution
public int nextInt(int n, double p)
public double pdf(int k)
public void setNandP(int n, double p)
n
- the number of trialsp
- the probability of success.public java.lang.String toString()
toString
in class java.lang.Object