%mathpiper,def="PoissonDistribution"

/* Guard against distribution objects with senseless parameters
   Anti-nominalism */

PoissonDistribution(l_IsRationalOrNumber)_(l<=0) <-- Undefined;

%/mathpiper





%mathpiper_docs,name="PoissonDistribution",categories="User Functions;Statistics & Probability"
*CMD PoissonDistribution --- Poisson distribution
*STD
*CALL
	PoissonDistribution(lambda)

*PARMS
{lambda} -- number, the expected number of occurrences that occur during the given interval

*DESC
The poisson distribution.

*E.G.
In> N(PMF(PoissonDistribution(5), 7))
Result: 0.1044448631

In> N(CDF(PoissonDistribution(5), 2))
Result: 0.1246520197


*SEE BinomialDistribution, BernoulliDistribution, DiscreteUniformDistribution, ChiSquareDistribution, ContinuousUniformDistribution, ExponentionalDistribution, GeometricDistribution, NormalDistribution, PoissonDistribution, tDistribution
%/mathpiper_docs