{"action":"created","issue":{"url":"https://api.github.com/repos/astropy/astropy/issues/4170","labels_url":"https://api.github.com/repos/astropy/astropy/issues/4170/labels{/name}","comments_url":"https://api.github.com/repos/astropy/astropy/issues/4170/comments","events_url":"https://api.github.com/repos/astropy/astropy/issues/4170/events","html_url":"https://github.com/astropy/astropy/pull/4170","id":107375430,"number":4170,"title":"NDDataBase now (tries to) set the uncertainties parent_nddata attribute","user":{"login":"MSeifert04","id":14200878,"avatar_url":"https://avatars.githubusercontent.com/u/14200878?v=3","gravatar_id":"","url":"https://api.github.com/users/MSeifert04","html_url":"https://github.com/MSeifert04","followers_url":"https://api.github.com/users/MSeifert04/followers","following_url":"https://api.github.com/users/MSeifert04/following{/other_user}","gists_url":"https://api.github.com/users/MSeifert04/gists{/gist_id}","starred_url":"https://api.github.com/users/MSeifert04/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/MSeifert04/subscriptions","organizations_url":"https://api.github.com/users/MSeifert04/orgs","repos_url":"https://api.github.com/users/MSeifert04/repos","events_url":"https://api.github.com/users/MSeifert04/events{/privacy}","received_events_url":"https://api.github.com/users/MSeifert04/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/astropy/astropy/labels/Bug","name":"Bug","color":"eb6420"},{"url":"https://api.github.com/repos/astropy/astropy/labels/nddata","name":"nddata","color":"c7def8"}],"state":"open","locked":false,"assignee":{"login":"mwcraig","id":1147167,"avatar_url":"https://avatars.githubusercontent.com/u/1147167?v=3","gravatar_id":"","url":"https://api.github.com/users/mwcraig","html_url":"https://github.com/mwcraig","followers_url":"https://api.github.com/users/mwcraig/followers","following_url":"https://api.github.com/users/mwcraig/following{/other_user}","gists_url":"https://api.github.com/users/mwcraig/gists{/gist_id}","starred_url":"https://api.github.com/users/mwcraig/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mwcraig/subscriptions","organizations_url":"https://api.github.com/users/mwcraig/orgs","repos_url":"https://api.github.com/users/mwcraig/repos","events_url":"https://api.github.com/users/mwcraig/events{/privacy}","received_events_url":"https://api.github.com/users/mwcraig/received_events","type":"User","site_admin":false},"milestone":null,"comments":2,"created_at":"2015-09-20T06:01:19Z","updated_at":"2015-09-21T19:12:03Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/astropy/astropy/pulls/4170","html_url":"https://github.com/astropy/astropy/pull/4170","diff_url":"https://github.com/astropy/astropy/pull/4170.diff","patch_url":"https://github.com/astropy/astropy/pull/4170.patch"},"body":"In #4152 I discovered that ``NDData`` togeter with the ``NDArithmeticMixin`` was not able to work with ``StdDevUncertainty`` as uncertainty. The problem was, that only the ``NDDataArray`` did set the ``parent_nddata`` attribute of the uncertainty while setting the uncertainty. Because the ``parent_nddata`` is necessary for ``StdDevUncertainty`` to work I added a few lines which at least try to set it in ``NDDataBase``.\r\n\r\nCurrently the ``except`` (when the uncertainty has no ``parent_nddata`` attribute) only makes a `pass` but it may also raise an Exception (which fails the current tests) or raise a warning (likewise) or be a case for the ``astropy.logging`` (but I only recently discovered this and I am not sure how to use it properly)\r\n\r\nSince this is only an aside issue of the original issue I hope this does not close the original issue.\r\n\r\nAny suggestions? And should I add a test case for the original problem (it's quite difficult, because all of ``nddata/mixins/tests/test_ndarithmetic.py``are based on ``NDDataArray`` not the different Mixins)"},"comment":{"url":"https://api.github.com/repos/astropy/astropy/issues/comments/142081306","html_url":"https://github.com/astropy/astropy/pull/4170#issuecomment-142081306","issue_url":"https://api.github.com/repos/astropy/astropy/issues/4170","id":142081306,"user":{"login":"MSeifert04","id":14200878,"avatar_url":"https://avatars.githubusercontent.com/u/14200878?v=3","gravatar_id":"","url":"https://api.github.com/users/MSeifert04","html_url":"https://github.com/MSeifert04","followers_url":"https://api.github.com/users/MSeifert04/followers","following_url":"https://api.github.com/users/MSeifert04/following{/other_user}","gists_url":"https://api.github.com/users/MSeifert04/gists{/gist_id}","starred_url":"https://api.github.com/users/MSeifert04/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/MSeifert04/subscriptions","organizations_url":"https://api.github.com/users/MSeifert04/orgs","repos_url":"https://api.github.com/users/MSeifert04/repos","events_url":"https://api.github.com/users/MSeifert04/events{/privacy}","received_events_url":"https://api.github.com/users/MSeifert04/received_events","type":"User","site_admin":false},"created_at":"2015-09-21T19:12:02Z","updated_at":"2015-09-21T19:12:02Z","body":"@embray: Thanks for adding the labels. Should I immediatly change my ``Change.rst`` text or wait for mwcraig? Also my written english seems a bit awkward to me, so if there is any proposed change I'll edit it."}}