Thanks for the workaround.
Joel
On Tuesday, June 6, 2017 at 9:21:39 AM UTC-6, vdelecroix wrote:
>
> An alternative way of taking quotient avoiding the "is_principal" call
>
> sage: Q = sage.rings.quotient_ring.QuotientRing_generic(R, I, 'a')
>
> Vincent
>
> On 06/06/2017 18:14, Joel Ornstein wrote:
> > Hi,
> >
> > For more correct context, I'm taking the quotient of the ring of
> integers
> > in my worksheet.
> >
> > f = QQ['t']({16:1, 0:262})
> > K.<s> = NumberField(f)
> > R = K.ring_of_integers()
> > QuotientRing(R, Ideal(263,s+1))
> >
> > I forgot to include that when simplifying the example.
> >
> > On Monday, June 5, 2017 at 1:26:18 PM UTC-6, William wrote:
> >>
> >> On Mon, Jun 5, 2017 at 12:17 PM, Vincent Delecroix
> >> <20100.d...@gmail.com <javascript:>> wrote:
> >>> On 05/06/2017 22:15, William Stein wrote:
> >>>>
> >>>> On Mon, Jun 5, 2017 at 11:48 AM, Joel Ornstein
> >>>> <joel.o...@colorado.edu <javascript:>> wrote:
> >>>>>
> >>>>> Hi all,
> >>>>>
> >>>>> I'm trying to work with several quotient rings and occasionally
> >> creating
> >>>>> the
> >>>>> quotient ring takes an extremely long time:
> >>>>>
> >>>>> f = QQ['t']({16:1, 0:262})
> >>>>> K.<s> = NumberField(f)
> >>>>> QuotientRing(K, Ideal(263,s+1))
> >>>>
> >>>>
> >>>> Question: What are you really trying to do exactly? The quotient of
> a
> >>>> number field by absolutely any nonzero ideal is just 0.
> >>>
> >>>
> >>> That's a good point. However, it would still be useful if Sage had the
> >> same
> >>> answer straight! Don't you think?
> >>>
> >>> I believe the OP was interested in the ring of integers of such number
> >> field
> >>
> >> Probably. Even then it would be very relevant to know what the OP
> >> actually wants to do with this quotient ring... Just arithmetic?
> >> Something harder?
> >>
> >> Here's a little worksheet working with the quotient as a module, which
> >> shows the quotient is cyclic of order 263:
> >>
> >>
> >>
> https://cocalc.com/projects/4a5f0542-5873-4eed-a85c-a18c706e8bcd/files/support/quotient-ring.ipynb?fullscreen
>
> >>
> >> It would be easy to build on that to do arithmetic quickly at least
> >> (without ever worrying about is_principal).
> >>
> >> William
> >
>
--
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.
