Poisson distribution

discrete curve

last updated: 2003-08-01

h12poisf.gif (1316 bytes)

h12poi2.gif (2040 bytes)h12poi1.gif (2089 bytes)The Poisson distribution (Siméon Denis Poisson, 1781-1840) can be obtained from the binomial distribution: let the number of events N go to infinity, where the most probable number of successes remains constant 1).
The function is used to be normalized with a factor e-a.
It is not symmetric, as the Gaussian distribution.

We can use the Poisson distribution in the case of a discrete probability process, with a constant frequency. Examples can be found in nuclear physics while counting elementary particles.


1) product of n and p, denoted as: a.