o h@sdZddlZddlmZgdZeddddZeddd d Zd d ZeddddZ eddddZ ed dddZ dS)zS Utilities for generating random numbers, random sequences, and random selections. N)py_random_state)powerlaw_sequencezipf_rvcumulative_distributiondiscrete_sequencerandom_weighted_sampleweighted_choice@csfddt|DS)zK Return sample sequence of length n from a power law distribution. csg|] }dqS) paretovariate.0iexponentseedr/var/www/html/construction_image-detection-poc/venv/lib/python3.10/site-packages/networkx/utils/random_sequence.py sz%powerlaw_sequence..)range)nrrrrrrsrr c Cs|dkrtd|dkrtd|d}d|} d|}|}t||d| }dd||}|||d|d||krI |Sq)awReturns 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 : integer, random_state, or None (default) Indicator of random number generation state. See :ref:`Randomness`. Returns ------- x : int Random value from Zipf distribution 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. r zxmin < 1za <= 1.0g?r ) ValueErrorrandomint) alphaxminra1buvxtrrrr s1  rcCs>dg}t|}tt|D]}||||||q |S)zFReturns normalized cumulative distribution from discrete distribution.g)sumrlenappend) distributioncdfpsumrrrrras rcs`ddl|dur |n|durt|ntdfddt|D}fdd|D}|S)a# Return sample sequence of length n from a given discrete distribution or discrete cumulative distribution. One of the following must be specified. distribution = histogram of values, will be normalized cdistribution = normalized discrete cumulative distribution rNz8discrete_sequence: distribution or cdistribution missingcsg|]}qSr)rr)rrrrsz%discrete_sequence..csg|] }|dqSr ) bisect_left)rs)bisectr(rrrs)r-rnx NetworkXErrorr)rr' cdistributionrinputseqseqr)r-r(rrrks  rcCsJ|t|kr tdt}t||kr!|t||t||kst|S)zReturns k items without replacement from a weighted sample. The input is a dictionary of items with weights as values. zsample larger than population)r%rsetaddrlist)mappingkrsamplerrrrs   rcCsB|t|}|D]\}}||8}|dkr|SqdS)zuReturns a single element from a weighted sample. The input is a dictionary of items with weights as values. rN)rr$valuesitems)r6rrndr7wrrrrsr)r N)r N)NNN)N) __doc__networkxr.networkx.utilsr__all__rrrrrrrrrrs   @