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Mikkel Meyer Andersen commented on MATH-578: -------------------------------------------- As far as I can see, Percentile contributes a lot to the longer execution time, so reopening MATH-417 for datasets of this type might be the right thing to do. > Decrease DescriptiveStatistics performance from 2.0 to 2.2 > ---------------------------------------------------------- > > Key: MATH-578 > URL: https://issues.apache.org/jira/browse/MATH-578 > Project: Commons Math > Issue Type: Bug > Affects Versions: 2.2 > Environment: Linux > Reporter: Paolo Repele > Assignee: Mikkel Meyer Andersen > Priority: Minor > Attachments: percentile.png > > > Switching between commons-math 2.0 to 2.2 we note how the > DescriptiveStatistics.addValue(double) has decrease the performance. > I tested with 2 million values. > DescriptiveStatistics ds = new DescriptiveStatistics(); > for(int i = 0; i<1000*1000*2; i++) { //2 million values > ds.addValue(v); > } > ds.getPercentile(50); > Seems that depending by the values inserted in the DescriptiveStatistics it > takes different time: > * with a single value (0) > ** 2.0 -> take ~500 ms > ** 2.2 -> take more than 10 minutes > * with 50% fixed value (0) and 50% Math.random() > ** 2.0 -> take ~500 ms > ** 2.2 -> take ~250000 ms -> ~250 second > * with 100% Math.random() > ** 2.0 -> take ~500 ms > ** 2.2 -> take ~70 ms -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira