On Mon, Sep 26, 2016 at 3:27 PM, Jonathan Bober <jwbo...@gmail.com> wrote: > In the matrix_integer_dense charpoly() function, there is a note in the > docstring which says "Linbox charpoly disabled on 64-bit machines, since it > hangs in many cases." > > As far as I can tell, that is not true, in the sense that (1) I have 64-bit > machines, and Linbox charpoly is not disabled, (2) > charpoly(algorithm='flint') is so horribly broken that if it were ever used > it should be quickly noticed that it is broken, and (3) I can't see anywhere > where it is actually disabled. > > So I actually just submitted a patch which removes this note while fixing > point (2). (Trac #21596). > > However... > > In some testing I'm noticing problems with charpoly(), so I'm wondering > where that message came from, and who knows something about it.
Do you know about "git blame", or the "blame" button when viewing any file here: https://github.com/sagemath/sage/tree/master/src > > The problems seem the likely cause of #21579, though I haven't actually been > able to conclusively blame that on linbox yet. I'm also not sure I've seen > linbox's charpoly() hang, exactly, but I do see very erratic behavior in how > long it takes: on a fixed matrix I have it typically takes 30 seconds, but > I've also seen it return the correct answer after 50 minutes. > > (I've also got the wrong answer sometimes, but there are some conversions > going on, and I've so far only seen the wrong answer for rational matrices, > which is why I've not get blamed linbox, though I am certainly leaning > towards blaming it.) > > Note: I'm currently testing on 7.4.beta6, so this is after the recent linbox > upgrade. But I was also having some problems before that. It is possible > that the recent upgrade made errors less likely, though. > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-devel@googlegroups.com. > Visit this group at https://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. -- William (http://wstein.org) -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
