{"action":"created","issue":{"url":"https://api.github.com/repos/igraph/igraph/issues/238","labels_url":"https://api.github.com/repos/igraph/igraph/issues/238/labels{/name}","comments_url":"https://api.github.com/repos/igraph/igraph/issues/238/comments","events_url":"https://api.github.com/repos/igraph/igraph/issues/238/events","html_url":"https://github.com/igraph/igraph/issues/238","id":13968882,"number":238,"title":"VF2 graph isomorphism takes very long or is stuck","user":{"login":"gaborcsardi","id":660288,"avatar_url":"https://avatars.githubusercontent.com/u/660288?v=3","gravatar_id":"","url":"https://api.github.com/users/gaborcsardi","html_url":"https://github.com/gaborcsardi","followers_url":"https://api.github.com/users/gaborcsardi/followers","following_url":"https://api.github.com/users/gaborcsardi/following{/other_user}","gists_url":"https://api.github.com/users/gaborcsardi/gists{/gist_id}","starred_url":"https://api.github.com/users/gaborcsardi/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/gaborcsardi/subscriptions","organizations_url":"https://api.github.com/users/gaborcsardi/orgs","repos_url":"https://api.github.com/users/gaborcsardi/repos","events_url":"https://api.github.com/users/gaborcsardi/events{/privacy}","received_events_url":"https://api.github.com/users/gaborcsardi/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/igraph/igraph/labels/Medium","name":"Medium","color":"ffdddd"}],"state":"closed","locked":false,"assignee":{"login":"gaborcsardi","id":660288,"avatar_url":"https://avatars.githubusercontent.com/u/660288?v=3","gravatar_id":"","url":"https://api.github.com/users/gaborcsardi","html_url":"https://github.com/gaborcsardi","followers_url":"https://api.github.com/users/gaborcsardi/followers","following_url":"https://api.github.com/users/gaborcsardi/following{/other_user}","gists_url":"https://api.github.com/users/gaborcsardi/gists{/gist_id}","starred_url":"https://api.github.com/users/gaborcsardi/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/gaborcsardi/subscriptions","organizations_url":"https://api.github.com/users/gaborcsardi/orgs","repos_url":"https://api.github.com/users/gaborcsardi/repos","events_url":"https://api.github.com/users/gaborcsardi/events{/privacy}","received_events_url":"https://api.github.com/users/gaborcsardi/received_events","type":"User","site_admin":false},"milestone":{"url":"https://api.github.com/repos/igraph/igraph/milestones/1","html_url":"https://github.com/igraph/igraph/milestones/0.7","labels_url":"https://api.github.com/repos/igraph/igraph/milestones/1/labels","id":311416,"number":1,"title":"0.7","description":null,"creator":{"login":"ntamas","id":195637,"avatar_url":"https://avatars.githubusercontent.com/u/195637?v=3","gravatar_id":"","url":"https://api.github.com/users/ntamas","html_url":"https://github.com/ntamas","followers_url":"https://api.github.com/users/ntamas/followers","following_url":"https://api.github.com/users/ntamas/following{/other_user}","gists_url":"https://api.github.com/users/ntamas/gists{/gist_id}","starred_url":"https://api.github.com/users/ntamas/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ntamas/subscriptions","organizations_url":"https://api.github.com/users/ntamas/orgs","repos_url":"https://api.github.com/users/ntamas/repos","events_url":"https://api.github.com/users/ntamas/events{/privacy}","received_events_url":"https://api.github.com/users/ntamas/received_events","type":"User","site_admin":false},"open_issues":0,"closed_issues":46,"state":"closed","created_at":"2013-04-15T13:08:09Z","updated_at":"2015-01-14T21:30:25Z","due_on":null,"closed_at":"2014-10-01T17:03:52Z"},"comments":13,"created_at":"2013-05-04T18:58:33Z","updated_at":"2015-11-03T16:02:41Z","closed_at":"2013-11-13T23:32:28Z","body":"See the attached two graphs\n\nlibrary(igraph)\ng1 <- read.graph(\"graph_first.txt\", dir=FALSE)\ng2 <- read.graph(\"graph_second.txt\", dir=FALSE)\ngraph.isomorphic.vf2(g1, g2)\n\n------------------------------------\nImported from Launchpad using lp2gh.\n\n * date created: 2012-09-17T22:05:18Z\n * owner: gabor.csardi\n * assignee: gabor.csardi\n * the launchpad url was https://bugs.launchpad.net/bugs/1052213\n"},"comment":{"url":"https://api.github.com/repos/igraph/igraph/issues/comments/153398560","html_url":"https://github.com/igraph/igraph/issues/238#issuecomment-153398560","issue_url":"https://api.github.com/repos/igraph/igraph/issues/238","id":153398560,"user":{"login":"szhorvat","id":1212871,"avatar_url":"https://avatars.githubusercontent.com/u/1212871?v=3","gravatar_id":"","url":"https://api.github.com/users/szhorvat","html_url":"https://github.com/szhorvat","followers_url":"https://api.github.com/users/szhorvat/followers","following_url":"https://api.github.com/users/szhorvat/following{/other_user}","gists_url":"https://api.github.com/users/szhorvat/gists{/gist_id}","starred_url":"https://api.github.com/users/szhorvat/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/szhorvat/subscriptions","organizations_url":"https://api.github.com/users/szhorvat/orgs","repos_url":"https://api.github.com/users/szhorvat/repos","events_url":"https://api.github.com/users/szhorvat/events{/privacy}","received_events_url":"https://api.github.com/users/szhorvat/received_events","type":"User","site_admin":false},"created_at":"2015-11-03T16:02:41Z","updated_at":"2015-11-03T16:02:41Z","body":"Of the isomorphism algorithms included in igraph, Bliss seems to be the fastest by far (at least for large or difficult graphs).  Have you considered using Bliss?\r\n\r\nCurrently Bliss does not support directed graphs.  Once pull request #873 gets merged, it will get support for directed graphs, vertex colored graphs and returning the generators of the automorphism group (which is typically more useful than returning all isomorphisms one by one, like VF2 does).  There really won't be a good reason to use VF2 except for edge coloured graphs and for subgraph isomorphism."}}