Actually, I use these polynomials to emulate what your CombinatorialFreeModule does on a much larger basis : everything that is hashable ;-)
I want to be able to index my variables with sets, with edges, with nodes, with almost anything we can come up with in Sage... Nathann On Nov 26, 3:39 pm, "Nicolas M. Thiery" <nicolas.thi...@u-psud.fr> wrote: > On Thu, Nov 26, 2009 at 05:29:47AM -0800, YannLC wrote: > > If you only want linear terms, you can also use an univariate > > polynomial ring > > > just treat x^i as x_i. > > > it's lightning fast and allow you to easily access coefficients. > > Variant: > > sage: F =CombinatorialFreeModule(QQ, NonNegativeIntegers()) > sage: x = F.basis() > sage: x[3] + 2* x[8] > B[3] + 2*B[8] > sage: f = x[3] + 2* x[8] > sage: f[8] > 2 > > This models more straightforwardly your problem. However, it's > currently (by far) not as fast as polynomials. This slowness will be > fixed as soon as the sparse free module code will have been > generalized to handle FreeModule(QQ, infinity). > > Best, > Nicolas > -- > Nicolas M. Thi ry "Isil" <nthi...@users.sf.net>http://Nicolas.Thiery.name/ -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
