Poisson Random Variable
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See: Random Variable, Poisson Probability Function, Poisson Experiment.
References
2012
- http://en.wikipedia.org/wiki/Poisson_distribution#Generating_Poisson-distributed_random_variables
- A simple algorithm to generate random Poisson-distributed numbers (pseudo-random number sampling) has been given by Knuth (Knuth, 1969):
While simple, the complexity is linear in λ. There are many other algorithms to overcome this. Some are given in Ahrens & Dieter, see References below. Also, for large values of λ, there may be numerical stability issues because of the term e−λ. One solution for large values of λ is Rejection sampling, another is to use a Gaussian approximation to the Poisson.
Inverse transform sampling is simple and efficient for small values of λ, and requires only one uniform random number u per sample. Cumulative probabilities are examined in turn until one exceeds u. algorithm poisson random number (Knuth).
- A simple algorithm to generate random Poisson-distributed numbers (pseudo-random number sampling) has been given by Knuth (Knuth, 1969):
init: Let L ← e−λ, k ← 0 and p ← 1. do: k ← k + 1. Generate uniform random number u in [0,1] and let p ← p × u. while p > L. return k − 1.
1969
- (Knuth, 1969) ⇒ Donald E. Knuth. (1969). Seminumerical Algorithms. The Art of Computer Programming, Volume 2. Addison Wesley.