Thanks for your response. I tried what you suggested and got the error you anticipated. So it looks like I need to work within Singular. The relevant page at the Singular site:
http://www.singular.uni-kl.de/Manual/latest/sing_1168.htm#SEC1227 Using the notation from the site just referenced, I end up with a ring, AC, in which the solutions are supposed to be stored in 'SOL'. I can execute singular.setring(AC), but cannot subsequently access the solutions. Thanks, Dave On Feb 25, 1:49 pm, Alex Raichev <tortoise.s...@gmail.com> wrote: > Hi Dave: > > Once you have your zero-dimensional ideal K within a Sage ring, you > could try the variety() command > > K.variety(ring=QQbar) or > K.variety(ring=CC) > > to get its solutions as algebraic numbers or complex floating point > numbers, respectively. See 'variety()' under > > http://www.sagemath.org/doc/ref/module-sage.rings.polynomial.multi-po... > > for more details. Problem is, variety() sometimes > fails:http://sagetrac.org/sage_trac/ticket/4622. > > Alex > > On Feb 25, 7:27 am,davidp<dav...@reed.edu> wrote: > > > Hi, > > > I have the following homogeneous Singular ideal defining a finite set > > of points in projective space. I would like to get numerical > > approximations for these points. > > > sage: S.ring() > > > // characteristic : 0 > > // number of vars : 4 > > // block 1 : ordering dp > > // : names x_3 x_2 x_1 x_0 > > // block 2 : ordering C > > sage: S.ideal() > > > x_1^3-x_3*x_2*x_0, > > x_3*x_2*x_1-x_0^3, > > x_2^3-x_3*x_1*x_0, > > x_3^3-x_2*x_1*x_0, > > x_2^2*x_1^2-x_3^2*x_0^2, > > x_3^2*x_1^2-x_2^2*x_0^2, > > x_3^2*x_2^2-x_1^2*x_0^2 > > sage: type(S.ideal()) > > <class 'sage.interfaces.singular.SingularElement'> > > > One way to go might be to map to a new ring, setting x_0 = 1, then use > > the nice Singular algorithm for finding the solutions: > > >http://www.singular.uni-kl.de/Manual/3-0-4/sing_582.htm > > > I couldn't figure out how to get the Singular "map" function to work > > with Sage, so I just converted equations using string commands (saved > > in "y" in the following code) then tried: > > > sage: R = singular.ring(0,'(x_3,x_2,x_1)','lp') > > sage: J = singular.ideal(y) > > sage: J > > > -x_3*x_2+x_1^3, > > x_3*x_2*x_1-1, > > -x_3*x_1+x_2^3, > > x_3^3-x_2*x_1, > > -x_3^2+x_2^2*x_1^2, > > x_3^2*x_1^2-x_2^2, > > x_3^2*x_2^2-x_1^2 > > sage: K = J.groebner() > > sage: M = K.solve(10,1) > > > I'm not sure where to go from there. Of course, I might be taking the > > wrong approach altogether. > > > Any advice would be appreciated. > > > Thanks, > > Dave --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
