Thank you, Nils ! Trying to pinpoint things by running a manual solution step by step, it seems that the stumbling oint is the division on two algebraics. I'll try to make a clear minimal example and report it. Le lundi 31 janvier 2022 à 00:49:22 UTC+1, Nils Bruin a écrit :
> On Saturday, 29 January 2022 at 13:51:14 UTC-8 Emmanuel Charpentier wrote: > >> /usr/local/sage-9/local/var/lib/sage/venv-python3.9/lib/python3.9/site-packages/sage/rings/qqbar.py >> >> in pari_field(self) >> >>> 3134 if self._pari_field is None: >>> 3135 pari_pol = self._field.pari_polynomial("y") >>> -> 3136 self._pari_field = pari_pol.nfinit(1) >>> 3137 return self._pari_field >>> 3138 >>> >>> cypari2/auto_gen.pxi in cypari2.gen.Gen_base.nfinit() >>> KeyboardInterrupt: >>> >>> >>> nf_init is a perfectly respectable place to hang. After interruption, > can you "%debug" and see what the value of pari_pol is? I'd expect that > nfinit determines the ring of integers, which means factoring the > discriminant. [QQbar shouldn't need the ring of integers of element > arithmetic, but this has been stumbled on before: QQbar often tries to find > an "optimized" form of the number field, which for small examples is often > quite doable and, if you end up doing a LOT of arithmetic in the same > field, is often worth the investment. However, because of factoring of the > discriminant, it's fully subexponential in complexity, whereas all the > things QQbar needs to do are polynomial time. So we already know that QQbar > will do things with the wrong theoretical asymptotic complexity. That can > come back and bite you, when reality and asymptotics start behaving > similarly (which happens eventually ... asymptotically speakinh) > -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/b74e28b5-1c59-40ad-b284-107fe6a1aa2dn%40googlegroups.com.