Pdf.Poisson Method

PdfPoisson Method

Evaluates the Poisson probability density function.

Namespace: Imsl.Stat
Assembly: ImslCS (in ImslCS.dll) Version: 6.5.2.0

Syntax

public static double Poisson(
	int k,
	double theta
)

Public Shared Function Poisson ( 
	k As Integer,
	theta As Double
) As Double

public:
static double Poisson(
	int k, 
	double theta
)

static member Poisson : 
        k : int * 
        theta : float -> float

Parameters

k: Type: SystemInt32
An int scalar for which the Poisson probability function is to be evaluated.
theta: Type: SystemDouble
A double scalar value representing the mean of the Poisson distribution.

Return Value

Type: Double
A double scalar value representing the probability that a Poisson random variable takes a value equal to k.

Remarks

Method Pdf.Poisson evaluates the probability density function of a Poisson random variable with parameter theta. theta, which is the mean of the Poisson random variable, must be positive. The probability function (with $\theta = theta$ ) is

$f(x) = e^{- \theta} \,\,\theta ^k /k!,\,\,\,\,\, for\,\,\,\, k = 0,\,\,1,\,\,2,\, \ldots$

Pdf.Poisson evaluates this function directly, taking logarithms and using the log gamma function.

Poisson ProbabilityFunction

Reference

Pdf Class

Imsl.Stat Namespace

Other Resources

Example