{"action":"created","issue":{"url":"https://api.github.com/repos/nipy/dipy/issues/831","labels_url":"https://api.github.com/repos/nipy/dipy/issues/831/labels{/name}","comments_url":"https://api.github.com/repos/nipy/dipy/issues/831/comments","events_url":"https://api.github.com/repos/nipy/dipy/issues/831/events","html_url":"https://github.com/nipy/dipy/issues/831","id":125924567,"number":831,"title":"ACT tracking example gives weird streamlines","user":{"login":"samuelstjean","id":3030760,"avatar_url":"https://avatars.githubusercontent.com/u/3030760?v=3","gravatar_id":"","url":"https://api.github.com/users/samuelstjean","html_url":"https://github.com/samuelstjean","followers_url":"https://api.github.com/users/samuelstjean/followers","following_url":"https://api.github.com/users/samuelstjean/following{/other_user}","gists_url":"https://api.github.com/users/samuelstjean/gists{/gist_id}","starred_url":"https://api.github.com/users/samuelstjean/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/samuelstjean/subscriptions","organizations_url":"https://api.github.com/users/samuelstjean/orgs","repos_url":"https://api.github.com/users/samuelstjean/repos","events_url":"https://api.github.com/users/samuelstjean/events{/privacy}","received_events_url":"https://api.github.com/users/samuelstjean/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":8,"created_at":"2016-01-11T11:35:30Z","updated_at":"2016-01-29T18:30:32Z","closed_at":null,"body":"So I was happily running the example from http://nipy.org/dipy/examples_built/tracking_tissue_classifier.html#example-tracking-tissue-classifier. \r\nThe last part about the ACT should only give streamlines going from GM to GM, but if you zoom on the results you get small nonsense streamlines. I also saw the same thing in another viewer, so it's probably not a bug of visualisation. So did I understand wrong what the ACT is doing, is the given segmentation in the example just too rough or is there a weird underlying bug?\r\n\r\n![screenshot from 2016-01-11 12 21 37](https://cloud.githubusercontent.com/assets/3030760/12232465/19403fe0-b85f-11e5-8c53-1ea82244984b.png)\r\n\r\nJust run block 1 from the example, then the last block about ACT with only valid streamlines and zoom in the window, you should be able to spot these fibers hopefully."},"comment":{"url":"https://api.github.com/repos/nipy/dipy/issues/comments/176899424","html_url":"https://github.com/nipy/dipy/issues/831#issuecomment-176899424","issue_url":"https://api.github.com/repos/nipy/dipy/issues/831","id":176899424,"user":{"login":"arokem","id":118582,"avatar_url":"https://avatars.githubusercontent.com/u/118582?v=3","gravatar_id":"","url":"https://api.github.com/users/arokem","html_url":"https://github.com/arokem","followers_url":"https://api.github.com/users/arokem/followers","following_url":"https://api.github.com/users/arokem/following{/other_user}","gists_url":"https://api.github.com/users/arokem/gists{/gist_id}","starred_url":"https://api.github.com/users/arokem/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/arokem/subscriptions","organizations_url":"https://api.github.com/users/arokem/orgs","repos_url":"https://api.github.com/users/arokem/repos","events_url":"https://api.github.com/users/arokem/events{/privacy}","received_events_url":"https://api.github.com/users/arokem/received_events","type":"User","site_admin":false},"created_at":"2016-01-29T18:30:32Z","updated_at":"2016-01-29T18:30:32Z","body":"Thanks Gab. I'm becoming more curious by the minute...\n\nOn Fri, Jan 29, 2016 at 10:29 AM, Gabriel Girard <notifications@github.com>\nwrote:\n\n> The tracking script you refer to uses another strategy to ensure seeds\n> placed in partial volume fraction of gray matter do not stop immediately\n> and produces longer streamlines. This is something else, that could be\n> included in dipy's tracking at some point, but is not ACT.\n>\n> —\n> Reply to this email directly or view it on GitHub\n> <https://github.com/nipy/dipy/issues/831#issuecomment-176898930>.\n>\n"}}