Hi Jean-Yves and everyone, OK, so it seems that some patch on the sage-combinat queue as of sage-5.4.1 solved the descents() problem in a more radical way than my sage-main patch. When my patch got merged into sage-main, the sage-combinat page would no longer apply, and so descents() once again became the old weird faux-descents function, while the correct descents function was now named standard_descents().
I wish I could confirm this but there seems to be no way to see the sage-combinat patches without being on the queue, let alone to see the old patches that are no longer in the queue. Either way, we should think about descents() when we rewrite tableau.py. Best regards, Darij On Thu, Oct 17, 2013 at 2:06 AM, Jean-Yves Thibon <jythi...@gmail.com> wrote: > Hi Darij, > > > I still have a sage-5.4.1 with all combinat patches up to december 2012 on > another machine, and t.descents() > does what I expect. I admit that "descents" is a bad name for this (these > are the descents of the inverse > permutation of the row reading in French convention, in French we use > "reculs" ( = recoils, or backsteps), > but it is traditional to use "descents" in English. > > Btw, the name "major index" comes from the military rank of McMahon (Foata > and Schutzenberger called it "the major's index") , > so there is only one "major index" .... > > All the best, > Jean-Yves > > Le mercredi 16 octobre 2013 22:07:38 UTC+2, Andrew Mathas a écrit : >> >> Hi Darij, >> >> I've not yet needed descent sets of tableaux in sage so I don't know what >> the code did previously or what it does now in this respect. I would hope, >> however, that a descents method for tableaux would return the descent set of >> a tableau, so if you have ensured that this is now happening I think that's >> great! >> >> Andrew >> >> On Wednesday, 16 October 2013 20:32:11 UTC+2, darijgrinberg wrote: >>> >>> Hello Jean-Yves, hello Andrew, >>> >>> I guess I should have something to say about this but I don't really >>> understand what is happening. When I wrote the #7983 patch, I was >>> being annoyed by the fact that there was no method on the Tableaux >>> class computing what everyone in combinatorics calls the descents, >>> whereas the descents() method on tableaux was computing something >>> rather unrelated (that, moreover, depends only on the shape if the >>> tableau is semistandard). I suspect the descents() method was some >>> kind of helper function for Jack or H-L related code. Anyway, I >>> decided to rename the old descents() method into a less ambiguous name >>> and to make descents() compute the actual descents. But I've quickly >>> got talked out of this, as this would deprecate some userbase code, so >>> instead I added a standard_descents() method and left descents() >>> untouched (only adding the warning to its doc). I was working on >>> sage-main all the time. >>> >>> Now, Jean-Yves (who, as far as I understand, has been using >>> sage-combinat) is saying he has been using descents() all the time and >>> since he is talking about standard tableaux, I assume that function >>> has been computing the actual descents rather than whatever it has >>> been computing on sage-main. Does this mean that the descents() >>> function on sage-combinat has been doing something completely >>> different from that on sage-main all the time before my #7983 patch? >>> That someone had done what I first had in mind (rename the old >>> descents() and reuse the name for the actual descents) long ago, and >>> now that my #7983 got merged in, the roles have switched? >>> >>> Either way, sorry for contributing to this muckup and thanks a lot for >>> any help in understanding it. >>> >>> Best regards, >>> Darij > > -- > You received this message because you are subscribed to the Google Groups > "sage-combinat-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-combinat-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-combinat-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-combinat-devel. > For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel. For more options, visit https://groups.google.com/groups/opt_out.
