{"action":"opened","issue":{"url":"https://api.github.com/repos/ComputationalRadiationPhysics/picongpu/issues/882","labels_url":"https://api.github.com/repos/ComputationalRadiationPhysics/picongpu/issues/882/labels{/name}","comments_url":"https://api.github.com/repos/ComputationalRadiationPhysics/picongpu/issues/882/comments","events_url":"https://api.github.com/repos/ComputationalRadiationPhysics/picongpu/issues/882/events","html_url":"https://github.com/ComputationalRadiationPhysics/picongpu/issues/882","id":79071562,"number":882,"title":"Position (Offset) in GasFreeFormula","user":{"login":"ax3l","id":1353258,"avatar_url":"https://avatars.githubusercontent.com/u/1353258?v=3","gravatar_id":"","url":"https://api.github.com/users/ax3l","html_url":"https://github.com/ax3l","followers_url":"https://api.github.com/users/ax3l/followers","following_url":"https://api.github.com/users/ax3l/following{/other_user}","gists_url":"https://api.github.com/users/ax3l/gists{/gist_id}","starred_url":"https://api.github.com/users/ax3l/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ax3l/subscriptions","organizations_url":"https://api.github.com/users/ax3l/orgs","repos_url":"https://api.github.com/users/ax3l/repos","events_url":"https://api.github.com/users/ax3l/events{/privacy}","received_events_url":"https://api.github.com/users/ax3l/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/ComputationalRadiationPhysics/picongpu/labels/refactoring","name":"refactoring","color":"c7def8"}],"state":"open","locked":false,"assignee":null,"milestone":{"url":"https://api.github.com/repos/ComputationalRadiationPhysics/picongpu/milestones/2","html_url":"https://github.com/ComputationalRadiationPhysics/picongpu/milestones/Open%20Beta","labels_url":"https://api.github.com/repos/ComputationalRadiationPhysics/picongpu/milestones/2/labels","id":395839,"number":2,"title":"Open Beta","description":"Tasks to complete until the release of our open beta (version 0.1)\r\n\r\nThe [beta](https://en.wikipedia.org/wiki/Software_release_life_cycle#Beta) release shall be useful for *physicist* that used a Particle-in-Cell code *before*. Experience with *compiling libraries from source* and a *good Linux knowledge* is required for the initial installation.\r\n","creator":{"login":"ax3l","id":1353258,"avatar_url":"https://avatars.githubusercontent.com/u/1353258?v=3","gravatar_id":"","url":"https://api.github.com/users/ax3l","html_url":"https://github.com/ax3l","followers_url":"https://api.github.com/users/ax3l/followers","following_url":"https://api.github.com/users/ax3l/following{/other_user}","gists_url":"https://api.github.com/users/ax3l/gists{/gist_id}","starred_url":"https://api.github.com/users/ax3l/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ax3l/subscriptions","organizations_url":"https://api.github.com/users/ax3l/orgs","repos_url":"https://api.github.com/users/ax3l/repos","events_url":"https://api.github.com/users/ax3l/events{/privacy}","received_events_url":"https://api.github.com/users/ax3l/received_events","type":"User","site_admin":false},"open_issues":89,"closed_issues":708,"state":"open","created_at":"2013-08-06T16:38:57Z","updated_at":"2015-05-21T16:31:48Z","due_on":null,"closed_at":null},"comments":0,"created_at":"2015-05-21T16:31:48Z","updated_at":"2015-05-21T16:31:48Z","closed_at":null,"body":"The `GasFreeFormula` should provide a simple interface `f(\\vec x)` where `x` is a position or offset (in normalized length) as it is in the current [master](https://github.com/ComputationalRadiationPhysics/picongpu/blob/ac82b4c96d5659380042b0e61f14092961e36120/src/picongpu/include/simulation_defines/param/gasConfig.param#L208).\r\n\r\nCurrently, a [cellOffset](https://github.com/ComputationalRadiationPhysics/picongpu/blob/e394fb1394ae186bde7d256a97578e3ec17e3207/src/picongpu/include/simulation_defines/param/gasConfig.param#L253) is used in `dev`. It is also not correctly converted to a `length` again since that would require a multiplication with the *normalized* cellSize and only in *addition* a multiplication with `unitLength` to get SI again.\r\n\r\nWe should therefore refactor the interface (multiply with cellSize beforehand) or update the examples since they are currently calculating the global position of the cell wrong."}}