I have some quite small graphs which are polyhedral, each is the 1-skeleton of a (connected convex) polyhedron such as a cube, tetrahedron, etc, constructed from a list of edge pairs.
I can get the faces of one of these, say G, via G.faces(). This returns a list of lists of vertices, each one being a list of the vertices of one face in some cyclic order. So each face in the list has an implied orientation. OK so far. What I want is for the orientations of the different faces to be coherent, coming from a single orientation of the surface. Expliticly that means that each edge xy, which will appear in exactly two faces, appears once in each direction, i.e. x before y (cyclically) in one and the other way round in the other. It is possible that G.faces() is already returning such a globally oriented list of faces, as experimentation suggests, but I need to be certain -- otherwise I can write code to check and if necessary reverse some faces. I would prefer not to have to though. The docstrong of G.faces() does not make this clear (at least not to me). -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/CAD0p0K5e9ch3tgrM2RAHxQieVOqG%2BEX37fyWj7BwF0ns-NTPpA%40mail.gmail.com.
