ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Mon, 21 Aug 2017 05:11:49 +0200Changing the weights in a graphhttps://ask.sagemath.org/question/38603/changing-the-weights-in-a-graph/ 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?vukovMon, 21 Aug 2017 05:11:49 +0200https://ask.sagemath.org/question/38603/checking isomorphism for weighted bipartite graphhttps://ask.sagemath.org/question/26130/checking-isomorphism-for-weighted-bipartite-graph/Hi, guys,
I am working on a problem involving checking if two weighted bipartite graphs are isomorphic.
I saw I can define a weighted graph in sage like this:
sage: X = Matrix([(0,0,1,1),(0,0,1,2),(0,1,1,0)])
sage: XX = BipartiteGraph(X,weighted=True)
sage: Y = Matrix([(1,0,2,0),(1,0,0,1),(1,0,1,0)])
sage: YY = BipartiteGraph(Y,weighted=True)
sage: W = Matrix([(1,0,2,0),(1,0,0,1),(1,0,2,0)])
sage: WW = BipartiteGraph(Z,weighted=True)
I swapped rows and columns of matrix defining X to get Y, so Y is isomorphic to X,
But since my graphs are weighted, I changed one element in Y from 1 to 2 to get W,
yet it still tell me XX and WW are isomorphic
sage: YY.is_isomorphic(XX)
True
sage: ZZ.is_isomorphic(XX)
True
Are there other functions I can use to check isomorphism for weighted bipartite graph?skylibraryTue, 10 Mar 2015 07:13:07 +0100https://ask.sagemath.org/question/26130/