According to wikipedia, graphs.CirculantGraph(n, [j_1, j_2, ...]) is connected if and only if gcd(n, j_1, j_2, ...) = 1. In this case, the gcd is 2. If Sage's definition is correct, it's defined as having 10 vertices, and vertex i is connected to vertices i+2, i-2, i+4, i-4, then even vertices will only be connected to other even vertices, so it should have two connected components.
(I'm not a graph theorist, and wikipedia is wikipedia, so take this with a grain of salt.) John On Monday, June 29, 2020 at 10:25:26 AM UTC-7 wdjo...@gmail.com wrote: > Hi: > > In SageMath version 9.1.beta3, I get > > sage: Gamma1 = graphs.CirculantGraph(*10*,[*2*,*4*]) > > sage: Gamma1.is_connected() > > False > > > My understanding is that all circulant graphs are connected. > > Is this a bug? > > - David > > > > > -- 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/f76cc4fa-4406-40ef-bf1b-7b285407f4d0n%40googlegroups.com.
