{"action":"created","issue":{"url":"https://api.github.com/repos/choderalab/openpathsampling/issues/468","repository_url":"https://api.github.com/repos/choderalab/openpathsampling","labels_url":"https://api.github.com/repos/choderalab/openpathsampling/issues/468/labels{/name}","comments_url":"https://api.github.com/repos/choderalab/openpathsampling/issues/468/comments","events_url":"https://api.github.com/repos/choderalab/openpathsampling/issues/468/events","html_url":"https://github.com/choderalab/openpathsampling/pull/468","id":149438070,"number":468,"title":"Fixed length TPS","user":{"login":"dwhswenson","id":8178546,"avatar_url":"https://avatars.githubusercontent.com/u/8178546?v=3","gravatar_id":"","url":"https://api.github.com/users/dwhswenson","html_url":"https://github.com/dwhswenson","followers_url":"https://api.github.com/users/dwhswenson/followers","following_url":"https://api.github.com/users/dwhswenson/following{/other_user}","gists_url":"https://api.github.com/users/dwhswenson/gists{/gist_id}","starred_url":"https://api.github.com/users/dwhswenson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/dwhswenson/subscriptions","organizations_url":"https://api.github.com/users/dwhswenson/orgs","repos_url":"https://api.github.com/users/dwhswenson/repos","events_url":"https://api.github.com/users/dwhswenson/events{/privacy}","received_events_url":"https://api.github.com/users/dwhswenson/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":{"login":"jhprinz","id":5091934,"avatar_url":"https://avatars.githubusercontent.com/u/5091934?v=3","gravatar_id":"","url":"https://api.github.com/users/jhprinz","html_url":"https://github.com/jhprinz","followers_url":"https://api.github.com/users/jhprinz/followers","following_url":"https://api.github.com/users/jhprinz/following{/other_user}","gists_url":"https://api.github.com/users/jhprinz/gists{/gist_id}","starred_url":"https://api.github.com/users/jhprinz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jhprinz/subscriptions","organizations_url":"https://api.github.com/users/jhprinz/orgs","repos_url":"https://api.github.com/users/jhprinz/repos","events_url":"https://api.github.com/users/jhprinz/events{/privacy}","received_events_url":"https://api.github.com/users/jhprinz/received_events","type":"User","site_admin":false},"milestone":{"url":"https://api.github.com/repos/choderalab/openpathsampling/milestones/1","html_url":"https://github.com/choderalab/openpathsampling/milestones/1.0","labels_url":"https://api.github.com/repos/choderalab/openpathsampling/milestones/1/labels","id":882847,"number":1,"title":"1.0","description":"Issues that should be solved before first public release.","creator":{"login":"dwhswenson","id":8178546,"avatar_url":"https://avatars.githubusercontent.com/u/8178546?v=3","gravatar_id":"","url":"https://api.github.com/users/dwhswenson","html_url":"https://github.com/dwhswenson","followers_url":"https://api.github.com/users/dwhswenson/followers","following_url":"https://api.github.com/users/dwhswenson/following{/other_user}","gists_url":"https://api.github.com/users/dwhswenson/gists{/gist_id}","starred_url":"https://api.github.com/users/dwhswenson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/dwhswenson/subscriptions","organizations_url":"https://api.github.com/users/dwhswenson/orgs","repos_url":"https://api.github.com/users/dwhswenson/repos","events_url":"https://api.github.com/users/dwhswenson/events{/privacy}","received_events_url":"https://api.github.com/users/dwhswenson/received_events","type":"User","site_admin":false},"open_issues":14,"closed_issues":59,"state":"open","created_at":"2014-11-27T17:27:40Z","updated_at":"2016-04-19T14:20:24Z","due_on":null,"closed_at":null},"comments":7,"created_at":"2016-04-19T11:59:46Z","updated_at":"2016-04-24T20:51:46Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/choderalab/openpathsampling/pulls/468","html_url":"https://github.com/choderalab/openpathsampling/pull/468","diff_url":"https://github.com/choderalab/openpathsampling/pull/468.diff","patch_url":"https://github.com/choderalab/openpathsampling/pull/468.patch"},"body":"Answering @jchodera’s request for fixed path length TPS. See https://github.com/choderalab/openpathsampling/pull/467#issuecomment-211494315 ff.\r\n\r\nIn the process, this should also do a little to clean up the approach currently used in TPS transitions and networks, to make it easier to re-use code.\r\n\r\n- [x] Draft `FixedLengthTPSTransition`\r\n- [x] Tests for `FixedLengthTPSTransition`\r\n- [x] Draft `FixedLengthTPSNetwork`\r\n- [x] Tests for `FixedLengthTPSNetwork`\r\n- [x] Simple example/test putting it all together\r\n- [x] Docstrings"},"comment":{"url":"https://api.github.com/repos/choderalab/openpathsampling/issues/comments/214033178","html_url":"https://github.com/choderalab/openpathsampling/pull/468#issuecomment-214033178","issue_url":"https://api.github.com/repos/choderalab/openpathsampling/issues/468","id":214033178,"user":{"login":"jhprinz","id":5091934,"avatar_url":"https://avatars.githubusercontent.com/u/5091934?v=3","gravatar_id":"","url":"https://api.github.com/users/jhprinz","html_url":"https://github.com/jhprinz","followers_url":"https://api.github.com/users/jhprinz/followers","following_url":"https://api.github.com/users/jhprinz/following{/other_user}","gists_url":"https://api.github.com/users/jhprinz/gists{/gist_id}","starred_url":"https://api.github.com/users/jhprinz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jhprinz/subscriptions","organizations_url":"https://api.github.com/users/jhprinz/orgs","repos_url":"https://api.github.com/users/jhprinz/repos","events_url":"https://api.github.com/users/jhprinz/events{/privacy}","received_events_url":"https://api.github.com/users/jhprinz/received_events","type":"User","site_admin":false},"created_at":"2016-04-24T20:51:46Z","updated_at":"2016-04-24T20:51:46Z","body":"Interesting connection. I never thought about it this way. My problem with this approach is, that OPS will try to generate only paths between  i and j that will take exactly `n` steps. In Markov Theory we have slightly different ensembles if I am not mistaken:\r\n\r\n```py\r\n# TPS i -> j\r\nSequence([\r\n    Length(1) & InX(stateA),\r\n    Length(N - 2) & Out(stateA & stateB),\r\n    Length(1) & InX(stateB)\r\n])\r\n```\r\n\r\n```py\r\n# TPS i -> j\r\nSequence([\r\n    Length(1) & InX(stateA),\r\n    Length(N - 2),\r\n    Length(1) & InX(stateB)\r\n])\r\n```\r\n\r\nSo, in MSMs we do not care about what happens intermediate steps (I could be wrong about TPS though, so please correct me!)\r\n\r\nJust rechecked the implemented code. I was wrong. FL-TPS is actually MSM with length = lagtime.\r\nThat is really useful.\r\n\r\nI think right now there is no shifting move, but it should be easy to implement. I assume it uses an existing A->B path and cuts some at one end and extends at the other. \r\n"}}