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# zipf_rv¶

zipf_rv(alpha, xmin=1, seed=None)[source]

Return a random value chosen from the Zipf distribution.

The return value is an integer drawn from the probability distribution ::math:

p(x)=\frac{x^{-\alpha}}{\zeta(\alpha,x_{min})},

where $$\zeta(\alpha,x_{min})$$ is the Hurwitz zeta function.

Parameters : alpha : float Exponent value of the distribution xmin : int Minimum value seed : int Seed value for random number generator x : int Random value from Zipf distribution ValueError: If xmin < 1 or If alpha <= 1

Notes

The rejection algorithm generates random values for a the power-law distribution in uniformly bounded expected time dependent on parameters. See [1] for details on its operation.

References

..[1] Luc Devroye, Non-Uniform Random Variate Generation,
Springer-Verlag, New York, 1986.

Examples

>>> nx.zipf_rv(alpha=2, xmin=3, seed=42)