On 22 November 2013 17:46, Peter Bruin <pjbr...@gmail.com> wrote: > The problem is indeed fixed by applying #13951 (which still needs > reviewing).
As Peter and I are both already authors and reviewers of the patcheson that ticket, we should probably find a third party to finish the review. John > > Peter > > Op vrijdag 8 november 2013 17:35:01 UTC schreef John Cremona: >> >> On 8 November 2013 16:11, Georgi Guninski <guni...@guninski.com> wrote: >> > I am not an expert, but is it normal to get negative canonical >> > height of a point on elliptic curve over number field? >> >> No, this is certainly an error. There is at least one outstanding >> patch relating to heights over number fields (#13951) but also there >> was a numerical instability problem fixed at #12509 which was not done >> perfectly (I know, I did it) and that might be the issue here too. >> >> Heights are supposed to be independent of the base field. Your curve >> and point are defined over Q where the height is computed as >> 0.0324132522964454 -- this uses a completely different implementation >> (in the pari library) which is more reliable, unfortunately. >> >> John Cremona >> >> > >> > sage: Z1.<Z>=ZZ[];Nf.<v>=NumberField(Z**16-2);E=EllipticCurve(Nf,[-87, >> > 504, -40320, 0, 0]);P=E(0,0) >> > sage: P.height() #not very fast >> > -0.150688795814905 >> > sage: P.height(precision=2000) >> > -0.15068879581490624...<snip> >> > >> > Works on cloud.sagemath too. >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups "sage-support" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> > an email to sage-support...@googlegroups.com. >> > To post to this group, send email to sage-s...@googlegroups.com. >> > Visit this group at http://groups.google.com/group/sage-support. >> > For more options, visit https://groups.google.com/groups/opt_out. > > -- > You received this message because you are subscribed to the Google Groups > "sage-support" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-support+unsubscr...@googlegroups.com. > To post to this group, send email to sage-support@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-support. > For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/groups/opt_out.
