Revision history [back]
 | 1 | initial version |
Here is one (not so elegant) possibility
sage: J = IndependentSets(graphs.CycleGraph(4))
sage: t = polygen(ZZ)
sage: F = 0
sage: for x in J:
....: N = len(set().union(G.neighbor_iterator(v) for v in x))
....: F += t^N
sage: F
2*x^2 + 4*x + 1
It is not so elegant because it constructs the explicit list of neighbors.
| | 2 | No.2 Revision |
Here is one (not so elegant) possibility
sage: J = IndependentSets(graphs.CycleGraph(4))
sage: t = polygen(ZZ)
polygen(ZZ, 't')
sage: F = 0
sage: for x in J:
....: N = len(set().union(G.neighbor_iterator(v) len(set().union(*[G.neighbor_iterator(v) for v in x))
x]))
....: F += t^N
sage: F
2*x^2 + 4*x 6t^2 + 1
It is not so elegant because it constructs the explicit list of neighbors.
