Hey Dan, I was referring to how the arrows correspond to the matrix values. However I can see the potential confusion and take blame for it. I agree that we should clarify this.
Best, Travis On Tuesday, February 18, 2014 3:56:21 PM UTC-8, bump wrote: > > In the Cartan type documentation (cartan_type.py) we find the following > statement: > > The direction of the arrows is the **opposite** (i.e. the > transpose) > > > of Bourbaki's convention, but agrees with > Kac's. > > > > > > > > For example, in type `C_2`, we > have:: > > > > > > > > sage: C2 = DynkinDiagram(['C',2]); > C2 > > > > > O=<=O > > > > 1 > 2 > > > > > C2 > > > > sage: > C2.cartan_matrix() > > > > [ 2 > -2] > > > > [-1 > 2] > > > > > This appears in the reference manual on this page: > > > http://www.sagemath.org/doc/reference/combinat/sage/combinat/root_system/cartan_type.html > > It is correct that Bourbaki's Cartan matrix is the transpose of Kac. > However both have > the same convention regarding Dynkin diagrams: the arrow points from the > long root > to the short. > > I think we should correct this. > -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel. For more options, visit https://groups.google.com/groups/opt_out.
