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Gilles Sadowski resolved STATISTICS-23. --------------------------------------- Resolution: Fixed Fixed in commit cbc1059a5156bbb1bb2b96d6ea323fd3ec601e05 ("master" branch). > Parameter names in "GammaDistribution" > -------------------------------------- > > Key: STATISTICS-23 > URL: https://issues.apache.org/jira/browse/STATISTICS-23 > Project: Apache Commons Statistics > Issue Type: Bug > Components: distribution > Reporter: Gilles Sadowski > Assignee: Gilles Sadowski > Priority: Critical > > After upgrading to v1.3 of "Commons RNG", a unit test for > {{GammaDistribution}} fails: > {noformat} > [ERROR] > GammaDistributionTest>ContinuousDistributionAbstractTest.testSampler:342 > Chisquare test failed p-value = 1.1102230246251565E-15 chisquare statistic = > 72.63199999999999. > value expected observed > 1 250 355 > 2 250 183 > 3 250 200 > 4 250 262 > {noformat} > It is caused by the inversion of the parameters when instantiating the > sampler (at line ): > {code:java} > public ContinuousDistribution.Sampler createSampler(final > UniformRandomProvider rng) { > // Gamma distribution sampler. > return new AhrensDieterMarsagliaTsangGammaSampler(rng, scale, > shape)::sample; > } > {code} > Things are back to normal when switching the {{scale}} and {{shape}} > arguments. -- This message was sent by Atlassian Jira (v8.3.4#803005)