Re: new Graph function + combinatorica: various problems
- To: mathgroup at smc.vnet.net
- Subject: [mg116375] Re: new Graph function + combinatorica: various problems
- From: "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com>
- Date: Sat, 12 Feb 2011 05:19:50 -0500 (EST)
- References: <ij2v05$7uu$1@smc.vnet.net>
I posted on graph conversion a couple of weeks ago. Shading of Graph can be prevented by prepending the System` context (System`Graph[...]). The two versions of conversion yield different plots in GraphPlot. Also my conversion route both yield minimum and maximum spanning trees (although for the graphs I tested them, they look identical). The ToCombinatoricaGraph conversion yields graphs for which (for all graphs I tested) the minimum spanning tree does not plot. Clearly, there is room for improvement in the graph area. << Combinatorica` << GraphUtilities` myM8Graph = GraphData["ZamfirescuGraph48"] (* conversion 1 *) myCombinatoricaGraph = FromAdjacencyMatrix[Normal[System`AdjacencyMatrix[myM8Graph]]]; myCombinatoricaGraph // ShowGraph MinimumSpanningTree[myCombinatoricaGraph] // ShowGraph MaximumSpanningTree[myCombinatoricaGraph] // ShowGraph (* conversion 2*) myCombinatoricaGraph = ToCombinatoricaGraph[myM8Graph]; myCombinatoricaGraph // ShowGraph MinimumSpanningTree[myCombinatoricaGraph] // ShowGraph MaximumSpanningTree[myCombinatoricaGraph] // ShowGraph Cheers -- Sjoerd On Feb 11, 10:20 am, Cupidio <andreatacche... at gmail.com> wrote: > Hi, > I'm experiencing some problems in combining the functionalities of > combinatorica and the built-in functions for graphs. > > In fact loading combinatorica shadows the built-in Graph function, and > makes its use impossible. But while I need some of the functions in > the combinatorica package (minimum/maximum spanning tree), i prefer > the graphic and "lexical" representation of the built-in Graph[]. > > How do I "save" Graph[] when I load combinatorica, or how can I make > it come back? > > Also (and this looks weird!), when i use ToCombinatoricaGraph[] (in > GraphUtilites package) to convert a graph, the resulting object can be > processed by MaximumSpanningTree[], yielding a correct result, but not > by MinimumSpanningTree[] which returns something like: > > MinimumSpanningTree[-Graph:<14,8,Directed>-] > > ...not even a combinatorica graph object. > > Thanks for your help!