networkx.utils.random_sequence.zipf_rv¶
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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
\[p(x)=\frac{x^{-\alpha}}{\zeta(\alpha, x_{\min})},\]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
Returns: x – Random value from Zipf distribution
Return type: Raises: 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.
Examples
>>> nx.zipf_rv(alpha=2, xmin=3, seed=42)
References
[1] Luc Devroye, Non-Uniform Random Variate Generation, Springer-Verlag, New York, 1986.