The code:
G=Graph(sparse=True, weighted=True)
G.add_edges([(0, 1, i), (0,8,1),(1,2,1),(2,3,1),(3,4,1),(4,5,1),(4,6,1),(6,7,1),(6,8,1),(8,9,1)])
M = G.weighted_adjacency_matrix()
show(M)
Here the (1,0) entry in the output matrix will be i, but I need -i. For that purpose, even I had defined (1,0,-i), it is not coming. Please give some hint.
Following Ricardo's suggestion works:
sage: G=DiGraph(sparse=True, weighted=True)
sage: G.add_edges([(0, 1, i), (0,8,1),(1,2,1),(2,3,1),(3,4,1),(4,5,1),(4,6,1),(6,
....: 7,1),(6,8,1),(8,9,1)])
sage: G.add_edges([(u[1], u[0], -u[2]) for u in list(G.edges())])
sage: G.weighted_adjacency_matrix()
[ 0 I 0 0 0 0 0 0 1 0]
[-I 0 1 0 0 0 0 0 0 0]
[ 0 -1 0 1 0 0 0 0 0 0]
[ 0 0 -1 0 1 0 0 0 0 0]
[ 0 0 0 -1 0 1 1 0 0 0]
[ 0 0 0 0 -1 0 0 0 0 0]
[ 0 0 0 0 -1 0 0 1 1 0]
[ 0 0 0 0 0 0 -1 0 0 0]
[-1 0 0 0 0 0 -1 0 0 1]
[ 0 0 0 0 0 0 0 0 -1 0]
But, of course, G.adjacency_matrix() is still boolean:
sage: G.adjacency_matrix()
[0 1 0 0 0 0 0 0 1 0]
[1 0 1 0 0 0 0 0 0 0]
[0 1 0 1 0 0 0 0 0 0]
[0 0 1 0 1 0 0 0 0 0]
[0 0 0 1 0 1 1 0 0 0]
[0 0 0 0 1 0 0 0 0 0]
[0 0 0 0 1 0 0 1 1 0]
[0 0 0 0 0 0 1 0 0 0]
[1 0 0 0 0 0 1 0 0 1]
[0 0 0 0 0 0 0 0 1 0]
HTH,
Asked: 2020-02-05 14:13:56 +0100
Seen: 611 times
Last updated: Feb 06 '20
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Probably you should create a
DiGraphfromG. Do you need the weight of (directed) edge(w,v)to be minus the weight of(v,w)?