René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Passing an incorrectly sized colour list to scatter should raise a relevant error","articleBody":"If the length of the `c` argument to `matplotlib.pyplot.scatter` doesn't match the size of the `x` and `y` arguments, a confusing error message is raised: `Invalid RGBA argument`. Contrast this with the error that results if `x` and `y` are not the same size: `x and y must be the same size`. The error message for an incorrect size `c` array should be made more clear.\r\n\r\n**Code for reproduction**\r\n\r\n```python\r\nimport numpy, matplotlib.pyplot as plt\r\nxs, ys = numpy.random.random((2, 10))\r\nc = numpy.random.random(9)\r\nplt.scatter(xs, ys, c=c)\r\n```\r\n\r\n**Actual outcome**\r\n\r\n```\r\n/usr/local/lib/python3.6/site-packages/matplotlib/colors.py in _to_rgba_no_colorcycle(c, alpha)\r\n    192         # float)` and `np.array(...).astype(float)` all convert \"0.5\" to 0.5.\r\n    193         # Test dimensionality to reject single floats.\r\n--\u003e 194         raise ValueError(\"Invalid RGBA argument: {!r}\".format(orig_c))\r\n    195     # Return a tuple to prevent the cached value from being modified.\r\n    196     c = tuple(c.astype(float))\r\n\r\nValueError: Invalid RGBA argument: 0.58430716187559439\r\n```\r\n\r\n**Expected outcome**\r\n\r\n```\r\nValueError: c and x must be the same size\r\n```\r\n\r\n  * Matplotlib Version: 2.0.2\r\n  * Python Version: 3.6.1","author":{"url":"https://github.com/MatthewJA","@type":"Person","name":"MatthewJA"},"datePublished":"2017-09-21T05:14:39.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":11},"url":"https://github.com/9209/matplotlib/issues/9209"}