Ask Your Question
1

Changing the weights in a graph

asked 2017-08-20 22:11:49 -0600

vukov gravatar image

Suppose I have a weighted graph G, and I want to change the weights of some of the edges. One way to do this is to output the weighted adjacency matrix, modify it, and then recreate the graph. Is there a more efficient way?

edit retag flag offensive close merge delete

1 answer

Sort by ยป oldest newest most voted
3

answered 2017-08-21 11:08:35 -0600

You can use the set_edge_label

sage: G = graphs.PetersenGraph()
sage: print G.edges()
[(0, 1, None), (0, 4, None), (0, 5, None), (1, 2, None), (1, 6, None), (2, 3, None), (2, 7, None), (3, 4, None), (3, 8, None), (4, 9, None), (5, 7, None), (5, 8, None), (6, 8, None), (6, 9, None), (7, 9, None)]
sage: i = 0
sage: for u,v in G.edges(labels=0):
....:     G.set_edge_label(u, v, i)
....:     i += 1
sage: print G.edges()
[(0, 1, 0), (0, 4, 1), (0, 5, 2), (1, 2, 3), (1, 6, 4), (2, 3, 5), (2, 7, 6), (3, 4, 7), (3, 8, 8), (4, 9, 9), (5, 7, 10), (5, 8, 11), (6, 8, 12), (6, 9, 13), (7, 9, 14)]
edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

Stats

Asked: 2017-08-20 22:11:49 -0600

Seen: 125 times

Last updated: Aug 21