I commented on the ticket that using R2.<x,y> = PolynomialRing(QQ, 2, order="lp") makes it work. So this is a relatively harmless and easy to fix interface bug...
On Mon, Mar 18, 2019 at 4:16 PM Rachel Player <rachelpla...@gmail.com> wrote: > > Hi Dima, > > Thanks for your reply. I opened the following ticket: > https://trac.sagemath.org/ticket/27508#ticket > > Cheers, > Rachel > > On Monday, 18 March 2019 13:21:52 UTC, Dima Pasechnik wrote: >> >> On Mon, Mar 18, 2019 at 1:01 PM Rachel Player <rachel...@gmail.com> wrote: >> > >> > I'd like to "remove squares" in some polynomials living in a polynomial >> > ring over QQ, in 2 variables: x,y. I tried to implement this by modding >> > out by the ideal (x^2 - x, y^2 - y). However, I have found that depending >> > on the ordering, the result of .mod() does not always output the >> > polynomial I am looking for. >> >> Thanks. This looks like a bug to me. >> Specifically, a bug in Singular, or in Singular interface to Sage, as >> if I do >> R2.<s,t>=PolynomialRing(QQ,2,order="lex", implementation="generic") >> then things work. (this is a slow Python implementation then) >> >> Care to open a trac ticket? >> >> Dima >> > >> > Please see attached for a code example: in the ring R2, the order is >> > specified as lex, and the polynomial x + y^2 does not reduce to x + y I >> > would like. This issue does not come up for the ring R1 (no ordering >> > specified explicitly), where both x + y^2 and x^2 + y reduce to x + y as >> > expected. >> > >> > Is there a way to force reduction even for the non-leading terms? >> > >> > Thanks, >> > Rachel >> > >> > >> > -- >> > 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 https://groups.google.com/group/sage-support. >> > For more options, visit https://groups.google.com/d/optout. > > -- > 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 https://groups.google.com/group/sage-support. > For more options, visit https://groups.google.com/d/optout. -- 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 https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
