Probabilities.PoissonPDF Method

Overload List

#SignatureDescription
1void PoissonPDF(TMtxVecInt X, Double Lambda, TDenseMtxVec Res)Poisson distribution PDF (vectorized).
2Double PoissonPDF(Int32 x, Double Lambda)Poisson probability mass function (PMF).

Overload 1: void PoissonPDF(TMtxVecInt X, Double Lambda, TDenseMtxVec Res)

Poisson distribution PDF (vectorized).

#NameDescription
1XDistribution domain, positive integer values or zeros.
2LambdaDistribution parameter, real positive value.
3ResAfter calculation stores the PDF calculated from X, alpha and beta. Length and Complex properties of Res are adjusted automatically to match Length and Complex properties of X.

Result: stored in self (calling object)

Overload 2: Double PoissonPDF(Int32 x, Double Lambda)

Poisson probability mass function (PMF).

#NameDescription
1xFunction domain, non-negative integer.
2LambdaRate parameter, real positive value.

Returns: Double - the Poisson probability mass function (PMF) at x using parameter Lambda. Returns NAN when Lambda<=0.

Remarks:

Computes the Poisson PMF, the probability of x events when the mean rate is Lambda:

PMF(x|lambda)=e^(-lambda) lambda^x/x!, x=0,1,2,...

Domain: x >= 0, lambda>0. For lambda <= 0 the result is NaN.

The Poisson distribution approximates the binomial when N is large and p small (good for N >= 20, p <= 0.05; very good for N >= 100, Np <= 10), so it is often called the distribution of "rare" events.

See Also: Probabilities.PoissonCDF, Probabilities.PoissonCDFInv