{"action":"created","issue":{"url":"https://api.github.com/repos/mwaskom/seaborn/issues/784","labels_url":"https://api.github.com/repos/mwaskom/seaborn/issues/784/labels{/name}","comments_url":"https://api.github.com/repos/mwaskom/seaborn/issues/784/comments","events_url":"https://api.github.com/repos/mwaskom/seaborn/issues/784/events","html_url":"https://github.com/mwaskom/seaborn/issues/784","id":119004504,"number":784,"title":"Standardization in z_score formula might be wrong","user":{"login":"MMCMA","id":10107101,"avatar_url":"https://avatars.githubusercontent.com/u/10107101?v=3","gravatar_id":"","url":"https://api.github.com/users/MMCMA","html_url":"https://github.com/MMCMA","followers_url":"https://api.github.com/users/MMCMA/followers","following_url":"https://api.github.com/users/MMCMA/following{/other_user}","gists_url":"https://api.github.com/users/MMCMA/gists{/gist_id}","starred_url":"https://api.github.com/users/MMCMA/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/MMCMA/subscriptions","organizations_url":"https://api.github.com/users/MMCMA/orgs","repos_url":"https://api.github.com/users/MMCMA/repos","events_url":"https://api.github.com/users/MMCMA/events{/privacy}","received_events_url":"https://api.github.com/users/MMCMA/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-11-26T09:30:48Z","updated_at":"2015-11-26T12:38:15Z","closed_at":"2015-11-26T11:53:56Z","body":"In seaborn version '0.5.1', I find in matrix.py -> z_score the formula (x-mean(x))/var(x) (`(z_scored - z_scored.mean()) / z_scored.var())`, this might be wrong. usually you devide over the standard deviation and not the variance to obtain a random variable with variance one. The code should then be `(z_scored - z_scored.mean()) / z_scored.std()` "},"comment":{"url":"https://api.github.com/repos/mwaskom/seaborn/issues/comments/159902243","html_url":"https://github.com/mwaskom/seaborn/issues/784#issuecomment-159902243","issue_url":"https://api.github.com/repos/mwaskom/seaborn/issues/784","id":159902243,"user":{"login":"michael-imbeault","id":7590794,"avatar_url":"https://avatars.githubusercontent.com/u/7590794?v=3","gravatar_id":"","url":"https://api.github.com/users/michael-imbeault","html_url":"https://github.com/michael-imbeault","followers_url":"https://api.github.com/users/michael-imbeault/followers","following_url":"https://api.github.com/users/michael-imbeault/following{/other_user}","gists_url":"https://api.github.com/users/michael-imbeault/gists{/gist_id}","starred_url":"https://api.github.com/users/michael-imbeault/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/michael-imbeault/subscriptions","organizations_url":"https://api.github.com/users/michael-imbeault/orgs","repos_url":"https://api.github.com/users/michael-imbeault/repos","events_url":"https://api.github.com/users/michael-imbeault/events{/privacy}","received_events_url":"https://api.github.com/users/michael-imbeault/received_events","type":"User","site_admin":false},"created_at":"2015-11-26T12:38:15Z","updated_at":"2015-11-26T12:38:15Z","body":"Make sure it's exactly the same issue before closing, it might be separate areas in the code I didn't check, I just know I had the same kind of issue fixed in clustermap (which probably calls the same function, but someone should verify)."}}