Thanks for your reply, David. I didn't know Singular could factor over the ring of formal power series. I'll check it out.
Alex On Jan 23, 11:09 pm, daveloeffler <dave.loeff...@gmail.com> wrote: > Hmm. I'm not a geometer myself, but nobody else seems to have bitten > on this one... > > If CC[[x_1, ..., x_n]] is the local ring of CC^n at the origin, we can > try to factorise the defining ideal I of V in this ring. This isn't > the same as your ring CC{x_1, ..., x_n} of germs of holomorphic > functions, but it's probably close enough, and gives the same answer > in your example. > > Sage at present doesn't natively support multivariate power series > rings, but Sage includes Singular, which does support these rings, and > can work with their ideals and Groebner bases. You can get a Singular > command line from the Sage console by typing "singular.console()". I > suggest you look at the Singular documentation. > > David > > On Jan 22, 12:46 am, Alex Raichev <tortoise.s...@gmail.com> wrote: > > > Hi all: > > > I have a geometry question. Given an ALGEBRAIC variety V in CC^n > > defined by a single polynomial and given a point p in V, how do you > > compute the number of (distinct) irreducible ANALYTIC components of V > > passing through p? > > > For example, let f = y^2 -x^2*(1 +x). Then the variety V(f) has two > > irreducible analytic components passing through (0,0), one for each > > factor of the decomposition > > > f = (y -x*sqrt(1+x)) *(y +x*sqrt(1+x)) > > > in CC{x,y}, the ring of power series convergent in a neighborhood of > > (0,0). > > > Alex --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---