Probabilities.PoissonCDF Method

Overload List

#SignatureDescription
1procedure PoissonCDF(const X: TMtxVecInt; Lambda: Double; const Res: TDenseMtxVec);Poisson distribution CDF (vectorized).
2function PoissonCDF(x: Integer; Lambda: Double): Double;Poisson cumulative distribution function (CDF).

Overload 1: procedure PoissonCDF(const X: TMtxVecInt; Lambda: Double; const Res: TDenseMtxVec);

Poisson distribution CDF (vectorized).

#NameDescription
1XDistribution domain, positive integer values or zeros.
2LambdaDistribution parameter, real positive value.
3ResAfter calculation stores the CDF 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: function PoissonCDF(x: Integer; Lambda: Double): Double;

Poisson cumulative distribution function (CDF).

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

Returns: Double - the Poisson cumulative distribution function (CDF) at x using parameter Lambda. Returns NAN when Lambda<=0.

Remarks:

Computes the Poisson CDF P(X <= x):

CDF(x|lambda)=e^(-lambda)sum_(j=0)^xlambda^j/j!=Q(x+1,lambda)

where Q(a,lambda) is the regularized upper incomplete gamma function (the implementation evaluates Q(x+1,lambda)). Domain: x >= 0, lambda>0; for lambda <= 0 the result is NaN and for x<0 the result is 0.

See Also: Probabilities.PoissonPDF, Probabilities.PoissonCDFInv