On 23 May 2011 05:51, Rob Beezer <[email protected]> wrote: > On May 22, 7:26 pm, François <[email protected]> wrote: >> If I am not mistaken about the meaning of the distribution_function method >> gsl may have actually corrected a bug and +oo is actually the value you are >> supposed to get, see this >> graph:http://en.wikipedia.org/wiki/File:Chi-square_distributionPDF.svg >> Would statisticians on the list care to comment? > > That sounds correct to me. GSL's "nu" is Wikipedia's "k", according > to the GSL documentation. The pdf has an x^{k/2-1} in it, and nothing > to counteract this term growing large for x close to zero when k=1, so > a value of +oo looks right. > > Rob
This is another worrying example of where someone wrote a doctest based on the output from Sage, without actually verifying the result is mathematically correct. Neither did the reviewer do so - assuming this test was written after the review process was introduced into Sage. The fact GSL had a bug (now corrected) is not so bad, as all non-trivial software has bugs. But for us to actually test for the buggy result seems pretty bad to me. Dave -- To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
