{"action":"created","issue":{"url":"https://api.github.com/repos/pandegroup/openmm/issues/867","labels_url":"https://api.github.com/repos/pandegroup/openmm/issues/867/labels{/name}","comments_url":"https://api.github.com/repos/pandegroup/openmm/issues/867/comments","events_url":"https://api.github.com/repos/pandegroup/openmm/issues/867/events","html_url":"https://github.com/pandegroup/openmm/issues/867","id":65956916,"number":867,"title":"TestCudaLocalEnergyMinimizer mixed fails","user":{"login":"swails","id":779022,"avatar_url":"https://avatars.githubusercontent.com/u/779022?v=3","gravatar_id":"","url":"https://api.github.com/users/swails","html_url":"https://github.com/swails","followers_url":"https://api.github.com/users/swails/followers","following_url":"https://api.github.com/users/swails/following{/other_user}","gists_url":"https://api.github.com/users/swails/gists{/gist_id}","starred_url":"https://api.github.com/users/swails/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/swails/subscriptions","organizations_url":"https://api.github.com/users/swails/orgs","repos_url":"https://api.github.com/users/swails/repos","events_url":"https://api.github.com/users/swails/events{/privacy}","received_events_url":"https://api.github.com/users/swails/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":19,"created_at":"2015-04-02T15:54:03Z","updated_at":"2015-04-28T22:32:54Z","closed_at":null,"body":"```\r\nswails@batman ~/src/build_openmm_dev $ ./TestCudaLocalEnergyMinimizer single\r\nDone\r\nswails@batman ~/src/build_openmm_dev $ ./TestCudaLocalEnergyMinimizer mixed\r\nexception: Assertion failure at TestCudaLocalEnergyMinimizer.cpp:133\r\nswails@batman ~/src/build_openmm_dev $ ./TestCudaLocalEnergyMinimizer double\r\nDone\r\n```\r\n\r\nThis is reproducible -- mixed precision always assert-fails at the same line.  If @peastman (or whoever goes about debugging this) can't repro, I'll provide more info."},"comment":{"url":"https://api.github.com/repos/pandegroup/openmm/issues/comments/97245662","html_url":"https://github.com/pandegroup/openmm/issues/867#issuecomment-97245662","issue_url":"https://api.github.com/repos/pandegroup/openmm/issues/867","id":97245662,"user":{"login":"jchodera","id":3656088,"avatar_url":"https://avatars.githubusercontent.com/u/3656088?v=3","gravatar_id":"","url":"https://api.github.com/users/jchodera","html_url":"https://github.com/jchodera","followers_url":"https://api.github.com/users/jchodera/followers","following_url":"https://api.github.com/users/jchodera/following{/other_user}","gists_url":"https://api.github.com/users/jchodera/gists{/gist_id}","starred_url":"https://api.github.com/users/jchodera/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jchodera/subscriptions","organizations_url":"https://api.github.com/users/jchodera/orgs","repos_url":"https://api.github.com/users/jchodera/repos","events_url":"https://api.github.com/users/jchodera/events{/privacy}","received_events_url":"https://api.github.com/users/jchodera/received_events","type":"User","site_admin":false},"created_at":"2015-04-28T22:32:54Z","updated_at":"2015-04-28T22:32:54Z","body":"> So within a certain range, the minimizer will find that changing the coordinates has no effect on the force (because it's making tiny changes that get lost when converting to single). That could certainly confuse it.\r\n\r\nDoes this suggest we should increase the `xtol` you set here to 1e-7 to eliminate this aspect of the problem?\r\nhttps://github.com/pandegroup/openmm/blob/master/openmmapi/src/LocalEnergyMinimizer.cpp#L117-L118\r\n```\r\n    if (!context.getPlatform().supportsDoublePrecision())\r\n        param.xtol = 1e-7;\r\n```"}}