Replying to ncohen:
[...]
Tell me if my answers above convinced you.
Yes: this ticket should not go without a graphs.IntersectionGraph. And intersection graphs of non-trivial BIBD are regular graph. So it is worth to have them at least in the doc of graphs.IntersectionGraph.
For the parameters: they are explicit in terms of (k,n) for TD and (v,k) for BIBD.
- for TD(k,n): lambda=(k-1)(k-2)+n-2, mu=k(k-1)
- for BIBD(v,k): lambda=(k-1)2+(v-1)/(k-1)-2, mu=k2
and this should be mentioned and tested.
By the way, why is there no BIBD in the Brouwer table?
Vincent
