Probabilities::PoissonPDF Function

Overload List

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

Overload 1: double PoissonPDF(int x, double Lambda);

Poisson probability mass function (PMF).

#NameTypeDescription
1xintFunction domain, non-negative integer.
2LambdadoubleRate parameter, real positive value.

Returns: 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
Declared in Dew::Math::Units::Probabilities · Dew.Math/Units.Probabilities.h · Cross-compiler

Overload 2: void PoissonPDF(TMtxVecInt *X, double Lambda, TDenseMtxVec *Res);

Poisson distribution PDF (vectorized).

#NameTypeDescription
1XTMtxVecInt *Distribution domain, positive integer values or zeros.
2LambdadoubleDistribution parameter, real positive value.
3ResTDenseMtxVec *After 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.
Declared in Dew::Math::Units::Probabilities · Dew.Math/Units.Probabilities.h · Cross-compiler