On 7/10/12 12:09 PM, Devl Devel wrote: > Hi Phil and All. > > Thanks for the welcome. I manage to get,build and test the SVN trunk branch > and took a look at the Spearmans Rank implementation. I did notice a few > test failures overall in the build such as RealVectorTest, hopefully they > are part of the build and not something I am missing in my checkout.
Don't worry about the RealVector test failures, that is a known issue that will hopefully soon be resolved. > > My only question for now is: how can I view the Jenkins build to see what's > not passing tests at the moment? I understand there are email alerts > however it would be good to see (readonly) the state of the current build > somehow. You can see the test output locally in /target/surefire-reports. You should be able to validate everything locally. > > I've also added a JIRA entry https://issues.apache.org/jira/browse/MATH-814 > and > on the wishlist > http://wiki.apache.org/commons/MathWishList#preview > > Will update once there is any progress :) Thanks! Phil > > Cheers > Dev > On Thu, Jul 5, 2012 at 10:24 PM, Devl Devel <devl.developm...@gmail.com>wrote: > >> Hi All, >> >> Below is a proposal for a new feature: >> >> *A concise description of the new feature / enhancement* >> * >> * >> I propose a new feature to implement the Kendall's Tau which is a measure >> of Association/Correlation between ranked ordinal data. >> >> *References to definitions and algorithms.* >> * >> *A basic description is available at >> http://en.wikipedia.org/wiki/Kendall_tau_rank_correlation_coefficient however >> the test implementation will follow that defined by "Handbook of >> Parametric and Nonparametric Statistical Procedures, Fifth Edition, Page >> 1393 Test 30, ISBN-10: 1439858012 | ISBN-13: 978-1439858011." >> >> The algorithm is proposed as follows. >> >> Given two rankings or permutations represented by a 2D matrix; columns >> indicate rankings (e.g. by an individual) and row are observations of each >> rank. The algorithm is to calculate the total number of concordant pairs of >> ranks (between columns), discordant pairs of ranks (between columns) and >> calculate the Tau defined as >> >> tau= (Number of concordant - number of discordant)/(n(n-1)/2) >> where n(n-1)/2 is the total number of possible pairs of ranks. >> >> The method will then output the tau value between 0 and 1 where 1 >> signifies a "perfect" correlation between the two ranked lists. >> >> Where ties exist within a ranking it is marked as neither concordant nor >> discordant in the calculation. An optional merge sort can be used to speed >> up the implementation. Details are in the wiki page. >> >> *Some indication of why the addition / enhancement is practically useful* >> * >> * >> Although this implementation is not particularly complex it would be >> useful to have it in a consistent format in the commons math package in >> addition to existing correlation tests. Kendall's Tau is used effectively >> in comparing ranks for products, rankings from search engines or >> measurements from engineering equipment. >> >> This is my first post on this list, I tried to follow the guidelines but >> let me know if I need to elaborate. >> >> Regards >> Dev >> >> --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
