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Poisson-Dirichlet Distribution


The Poisson-Dirichlet distribution with parameter theta>0 is the statistical distribution of the decreasing rearrangement of the fragments of a random stick-breaking construction. In this one-parameter convention, also denoted PD(0,theta), take independent random variables U_j with probability density function thetau^(theta-1) on (0,1) and put

 B_j=(1-U_j)product_(i<j)U_i.

The decreasing rearrangement (L_1,L_2,...) has nonnegative entries summing to 1 almost surely. For theta=1, the variables U_j have a uniform distribution on (0,1).


See also

Beta Distribution, Prime Factorization, Statistical Distribution, Uniform Distribution

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References

Pitman, J. and Yor, M. "The Two-Parameter Poisson-Dirichlet Distribution Derived from a Stable Subordinator." Ann. Probab. 25, 855-900, 1997. https://doi.org/10.1214/aop/1024404422.

Cite this as:

Weisstein, Eric W. "Poisson-Dirichlet Distribution." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Poisson-DirichletDistribution.html

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