I found this link:
It talks about a graph database. My question isn't really about this database, but the fact that this database has the Lovasz number makes me wonder if Sage can calculate the Lovasz number of a graph???
BUMP: Did any one get the code (in the answer below) to work? It calls an error when I run it. And, I have no idea what the code is doing so I can't really figure out the error :)
File "/tmp/tmp0_qsPp/___code___.py", line 21, in lovasz_theta c = -cvxopt.base.matrix([_sage_const_0p0 ]*(n-_sage_const_1 ) + [_sage_const_2p0 ]*(d-n)) TypeError: invalid type in list