René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Incorrect uses of is_numlike","articleBody":"`cbook.is_numlike(obj)` is implemented by checking whether `obj + 1` raises.  In particular, this means that numpy numeric arrays are considered as numlikes, which appears to be unintended in most cases.\r\n\r\nAs an example (not the only one), while\r\n```\r\nplt.scatter([0], [0], marker=[[0, 0], [0, 1], [1, 1]])\r\n```\r\nworks as expected,\r\n```\r\nplt.scatter([0], [0], marker=np.array([[0, 0], [0, 1], [1, 1]]))\r\n```\r\nraises an exception because code in `markers` checks (effectively, in this case) for whether `markers` is \"numlike\", and, if so, considers it to be a number of sides for a polygon marker (at the beginning of `_set_tuple_marker`).\r\n\r\nIn my never-ending push to get rid of as much of `cbook` as possible :-), I would suggest replacing calls to `is_numlike` to either `np.issubdtype(type(obj), np.number)` (if we were using numpy\u003e=1.9.0, this could be `isinstance(obj, abc.Number)`) or, if it was actually intended to accept arrays, `np.issubtype(np.asarray(obj).dtype, np.number)` -- we may as well distinguish explicitly between the two cases.\r\n\r\nEdit: Actually one can just define somewhere `Number = (abc.Number, np.number)`, then `isinstance(obj, Number)` will work even for older numpys (I guess).","author":{"url":"https://github.com/anntzer","@type":"Person","name":"anntzer"},"datePublished":"2017-01-10T23:26:36.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/7795/matplotlib/issues/7795"}