Re: tab-delimited file to graph

*To*: mathgroup at smc.vnet.net*Subject*: [mg69455] Re: tab-delimited file to graph*From*: dh <dh at metrohm.ch>*Date*: Wed, 13 Sep 2006 04:01:35 -0400 (EDT)*References*: <ee64q5$7s4$1@smc.vnet.net>

Hi Aitor, I understand that you have a list: dat of 2 element lists. You are looking for a matrix adj that, given 2 elements i,j, has a 1 at adj[[i,j]] and a -1 at adj[[j,i]]. Well, first, create a zero matrix of the requested size: adj=Array[0 &, {n, n}] then fill in the 1's: (adj [[Sequence @@ #]] = 1)& /@ dat now make the matrix antisymmetric: adj -= -Transpose[adj] Daniel aitor69gonzalez at gmail.com wrote: > Hello, > > I have a directed graph "mygraph" in a tab delimited file that looks > like this: > v1 v2 > v2 v3 > v3 v1 > v1 v4 > I would like to import this graph into mathematica, so that I can take > advantage of the -DiscreteMath`Combinatorica`- functions. So far, I was > only able to import it with Import["mygraph","TSV"] into a list of > two-item lists. Now, I am stuck there. Can somebody help me to convert > this list of two-item lists into a matrix or adjacency list of a > directed graph? > > Thank you in advance, > > Aitor >