ó |£*^c@sŹdZddlZddlZddlZdjdddgƒZddlZddd„Z d d „Z d d „Z d dd„Z d d d„Zd„Zd„Zddd„Zd„Zd„ZdS(sT Utilities for generating random numbers, random sequences, and random selections. i’’’’Ns sAric Hagberg (hagberg@lanl.gov)sDan Schult(dschult@colgate.edu)s Ben Edwards(bedwards@cs.unm.edu)i2c Ks©tjdtƒd}|}xs||kr‘|||}g|D]*}t|ttt|ƒƒdƒƒ^qA}tj|ƒr„|S|d7}qWtj d|ƒ‚dS(Ns&create_degree_sequence() is deprecatediis/Exceeded max (%d) attempts at a valid sequence.( t _warningstwarntDeprecationWarningtmintmaxtinttroundtnxtis_valid_degree_sequencet NetworkXError( tnt sfunctiont max_triestkwdsttriestmax_degttrialseqtstseq((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pytcreate_degree_sequences 7gš?cCs&gt|ƒD]}tj|ƒ^q S(sH Return sample sequence of length n from a Pareto distribution. (trangetrandomt paretovariate(R texponentti((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pytpareto_sequenceCsg@cCs*gt|ƒD]}tj|dƒ^q S(sK Return sample sequence of length n from a power law distribution. i(RRR(R RR((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pytpowerlaw_sequenceJsic Csę|dkrtdƒ‚n|dkr6tdƒ‚n|dk rRtj|ƒn|d}d|}xytrįdtjƒ}tjƒ}t||d| ƒ}dd||}|||d|d||kriPqiqiW|S(s%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 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.zipf_rv(alpha=2, xmin=3, seed=42) # doctest: +SKIP References ---------- ..[1] Luc Devroye, Non-Uniform Random Variate Generation, Springer-Verlag, New York, 1986. isxmin < 1sa <= 1.0gš?iN(t ValueErrortNoneRtseedtTrueR( talphatxminRta1tbtutvtxtt((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pytzipf_rvPs -       $cCs&gt|ƒD]}t||ƒ^q S(s£Return a sample sequence of length n from a Zipf distribution with exponent parameter alpha and minimum value xmin. See Also -------- zipf_rv (RR'(R RR t_((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pyt zipf_sequenceŽscCs)gt|ƒD]}tjd|ƒ^q S(sI Return sample sequence of length n from a uniform distribution. i(RRtuniform(R R((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pytuniform_sequence˜scCsfg}|jdƒtt|ƒƒ}x:tdt|ƒƒD]#}|j|||||ƒq;W|S(sEReturn normalized cumulative distribution from discrete distribution.gi(tappendtfloattsumRtlen(t distributiontcdftpsumR((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pytcumulative_distributionŸs  !c Csddl}|dk r!|}n*|dk r<t|ƒ}ntjdƒ‚gt|ƒD]}tjƒ^qX}g|D]}|j||ƒd^qw}|S(s* 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 i’’’’Ns8discrete_sequence: distribution or cdistribution missingi(tbisectRR3RR RRt bisect_left( R R0t cdistributionR4R1RtinputseqRR((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pytdiscrete_sequenceŖs     %)cCs`|t|ƒkr!tdƒ‚ntƒ}x)t|ƒ|krU|jt|ƒƒq-Wt|ƒS(sReturn k items without replacement from a weighted sample. The input is a dictionary of items with weights as values. ssample larger than population(R/Rtsettaddtweighted_choicetlist(tmappingtktsample((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pytrandom_weighted_sampleÉs  cCsWtjƒt|jƒƒ}x4|jƒD]&\}}||8}|dkr)|Sq)WdS(stReturn a single element from a weighted sample. The input is a dictionary of items with weights as values. iN(RR.tvaluestitems(R=trndR>tw((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pyR;Õs   (t__doc__RtsystnetworkxRtjoint __author__twarningsRRRRRR'R)R+R3R8R@R;(((sr/home/gitlab-runner/builds/8480fa44/0/bergerc/fluidmanager-web/art-framework/bin/networkx/utils/random_sequence.pyts"      0  >