networkx.utils.random_sequence.zipf_rv¶
-
zipf_rv
(alpha, xmin=1, seed=None)[source]¶ Returns 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 (integer, random_state, or None (default)) – Indicator of random number generation state. See Randomness.
- 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.utils.zipf_rv(alpha=2, xmin=3, seed=42) 8
References
- 1
Luc Devroye, Non-Uniform Random Variate Generation, Springer-Verlag, New York, 1986.