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Phil Steitz commented on MATH-1154: ----------------------------------- Applied Thomas' patch in commit a3fdeb4da91d8aef50f40a3f9906494593ce2eca. Still todo to resolve (for 3.x): update javadoc on distribution class constructors to recommend passing null RandomGenerator when sampling is not going to be used. > Statistical tests in stat.inference package are very slow due to implicit > RandomGenerator initialization > -------------------------------------------------------------------------------------------------------- > > Key: MATH-1154 > URL: https://issues.apache.org/jira/browse/MATH-1154 > Project: Commons Math > Issue Type: Bug > Affects Versions: 3.3 > Reporter: Otmar Ertl > Attachments: MATH-1154.patch, math3.patch > > > Some statistical tests defined in the stat.inference package (e.g. > BinomialTest or ChiSquareTest) are unnecessarily very slow (up to a factor 20 > slower than necessary). The reason is the implicit slow initialization of a > default (Well19937c) random generator instance each time a test is performed. > The affected tests create some distribution instance in order to use some > methods defined therein. However, they do not use any method for random > generation. Nevertheless a random number generator instance is automatically > created when creating a distribution instance, which is the reason for the > serious slowdown. The problem is related to MATH-1124. > There are following solutions: > 1) Fix the affected statistical tests by passing a light-weight > RandomGenerator implementation (or even null) to the constructor of the > distribution. > 2) Or use for all distributions a RandomGenerator implementation that uses > lazy initialization to generate the Well19937c instance as late as possible. > This would also solve MATH-1124. > I will attach a patch proposal together with a performance test, that will > demonstrate the speed up after a fix. -- This message was sent by Atlassian JIRA (v6.3.4#6332)