{"action":"created","issue":{"url":"https://api.github.com/repos/JuliaLang/julia/issues/10172","labels_url":"https://api.github.com/repos/JuliaLang/julia/issues/10172/labels{/name}","comments_url":"https://api.github.com/repos/JuliaLang/julia/issues/10172/comments","events_url":"https://api.github.com/repos/JuliaLang/julia/issues/10172/events","html_url":"https://github.com/JuliaLang/julia/issues/10172","id":57419723,"number":10172,"title":"Add a Levi-Civita Symbol (parity of permutation) to Base","user":{"login":"pabloferz","id":8410335,"avatar_url":"https://avatars.githubusercontent.com/u/8410335?v=3","gravatar_id":"","url":"https://api.github.com/users/pabloferz","html_url":"https://github.com/pabloferz","followers_url":"https://api.github.com/users/pabloferz/followers","following_url":"https://api.github.com/users/pabloferz/following{/other_user}","gists_url":"https://api.github.com/users/pabloferz/gists{/gist_id}","starred_url":"https://api.github.com/users/pabloferz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pabloferz/subscriptions","organizations_url":"https://api.github.com/users/pabloferz/orgs","repos_url":"https://api.github.com/users/pabloferz/repos","events_url":"https://api.github.com/users/pabloferz/events{/privacy}","received_events_url":"https://api.github.com/users/pabloferz/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":17,"created_at":"2015-02-12T05:37:48Z","updated_at":"2015-02-12T22:49:44Z","closed_at":null,"body":"As pointed out <a href=\"https://groups.google.com/forum/#!topic/julia-users/r9hX-HZqflo\">here</a>. It would be useful to have a Levi-Civita Symbol implementation in Base.\r\n\r\nIt's not clear what the name should be, some proposals are `levicivita`, `parity`, `sign`, `signature`, or `sgn`, although `sign(v::AbstractVector)` already returns an element-wise version of `sign`.\r\n\r\nAnyway, I wrote three implementations in this <a href=\"https://gist.github.com/pabloferz/01675f1bf4c8be359767\">gist</a>. The `levicivita_inplace_check` in there is the fastest (I think).\r\n\r\nAlso, I think it might be added in `combinatorics.jl` but I'm not sure.\r\n\r\nWhat do you think?"},"comment":{"url":"https://api.github.com/repos/JuliaLang/julia/issues/comments/74170670","html_url":"https://github.com/JuliaLang/julia/issues/10172#issuecomment-74170670","issue_url":"https://api.github.com/repos/JuliaLang/julia/issues/10172","id":74170670,"user":{"login":"pabloferz","id":8410335,"avatar_url":"https://avatars.githubusercontent.com/u/8410335?v=3","gravatar_id":"","url":"https://api.github.com/users/pabloferz","html_url":"https://github.com/pabloferz","followers_url":"https://api.github.com/users/pabloferz/followers","following_url":"https://api.github.com/users/pabloferz/following{/other_user}","gists_url":"https://api.github.com/users/pabloferz/gists{/gist_id}","starred_url":"https://api.github.com/users/pabloferz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pabloferz/subscriptions","organizations_url":"https://api.github.com/users/pabloferz/orgs","repos_url":"https://api.github.com/users/pabloferz/repos","events_url":"https://api.github.com/users/pabloferz/events{/privacy}","received_events_url":"https://api.github.com/users/pabloferz/received_events","type":"User","site_admin":false},"created_at":"2015-02-12T22:49:44Z","updated_at":"2015-02-12T22:49:44Z","body":"http://journals.aps.org/pr/abstract/10.1103/PhysRev.74.456"}}