[sage-devel] Re: import / export of graphs (modifications in graph theory)

2012-07-08 Thread Dima Pasechnik
On Monday, 9 July 2012 10:22:31 UTC+8, Birk Eisermann wrote: > > Hello!! > > What is your opinion about improving the export and import of graphs? > > My conclusion of the sage-devel thread "Code duplication and aliases in > methods" is that at the moment the source code in graph theory is not

[sage-devel] import / export of graphs (modifications in graph theory)

2012-07-08 Thread Birk Eisermann
Hello!! What is your opinion about improving the export and import of graphs? My conclusion of the sage-devel thread "Code duplication and aliases in methods" is that at the moment the source code in graph theory is not so optimal organized. As promised, I want to show some modifications that

Re: [sage-devel] Re: Code duplication and aliases in methods

2012-07-08 Thread Birk Eisermann
Hi Jason, Good point! Networkx comes quite close. I agree with the distinction between graphs and algorithms as in networkx. Graphs objects just for storage of the graph data. But for algorithms, I have different picture which is closer to how it is in sage... e.g. no segmentation (hence als

Re: [sage-devel] comparisons in real number field

2012-07-08 Thread Mike Hansen
There is a patch at http://trac.sagemath.org/sage_trac/ticket/7160 which uses the embedding for the comparison, but there are two doctest failures still. --Mike On Sun, Jul 8, 2012 at 8:54 AM, vdelecroix <20100.delecr...@gmail.com> wrote: > Hi, > > Once I initialize a number field with a real emb

[sage-devel] comparisons in real number field

2012-07-08 Thread vdelecroix
Hi, Once I initialize a number field with a real embedding, I would like (as a user) that the order defined on the number field (ie the answers of comparisons) is the one induced from RR. This is not the case right now. I started to implement the thing for quadratic number field, and it works well

[sage-devel] Bug in DiGraph.is_isomorphic?

2012-07-08 Thread Timo
Hi, the following seems suspicious to me: sage: M = matrix(2,[1,3,2,0]) sage: G = DiGraph(M, loops=True, multiedges=True) sage: H = DiGraph(M.transpose(), loops=True, multiedges=True) sage: G.is_isomorphic(H) True Strangely enough, this works fine: sage: M = matrix(2,[1,3,1,0]) sage: G = DiGraph