René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"plot.scatter: negative or null values lead to strange behavior on log scale","articleBody":"\u003c!--To help us understand and resolve your issue, please fill out the form to the best of your ability.--\u003e\r\n\u003c!--You can feel free to delete the sections that do not apply.--\u003e\r\n\r\n### Bug report\r\nRelated issues have already been reported but I think a simpler case is worth mentioning:\r\n\r\n**Bug summary**\r\n\r\n\u003c!--A short 1-2 sentences that succinctly describes the bug--\u003e\r\nWith negative or null values, log scale fails (although it does not crashes) discarding (masking) more points than the ones corresponding to the invalid negative or null values. At least a WARNING would be welcome.\r\n\r\n**Code for reproduction**\r\n\u003c!--A minimum code snippet required to reproduce the bug, also minimizing the number of dependencies required--\u003e\r\nNormal behavior: only positive values in `y` :\r\n```python\r\nx = [1, 2, 3, 4]\r\ny = [1, 10, 50, 100]\r\nplt.scatter(x, y)\r\nplt.yscale('log')\r\n```\r\n**Actual outcome**: \r\n![image](https://user-images.githubusercontent.com/8144090/44329069-c1816380-a463-11e8-970d-1cb8ebeef2c1.png)\r\n\r\nBug: with value 0 in `y` (idem with negative values):\r\n```python\r\nx = [1, 2, 3, 4]\r\ny = [0, 10, 50, 100]\r\nplt.scatter(x, y)\r\nplt.yscale('log')\r\n```\r\n**Actual outcome**: only the last point is displayed.\r\n\u003c!--The output produced by the above code, which may be a screenshot, console output, etc.--\u003e\r\n![image](https://user-images.githubusercontent.com/8144090/44329224-2ccb3580-a464-11e8-9469-53bc7c69c13b.png)\r\n\r\n**Expected outcome**\r\nI understand that default behavior is masking of non positive values. But it seems that more values are masked. I tried chaging parameter `nonposy` : `plt.yscale('log', nonposy='clip')` but the behavior is the same.\r\nAt least a WARNING should be displayed about presence of negative or null values not compatible with log scale.\r\n\r\n\u003c!--A description of the expected outcome from the code snippet--\u003e\r\n\u003c!--If this used to work in an earlier version of Matplotlib, please note the version it used to work on--\u003e\r\n\r\n**Matplotlib version**\r\n\u003c!--Please specify your platform and versions of the relevant libraries you are using:--\u003e\r\n  * Operating system: Ubuntu 14.04.3 LTS\r\n  * Matplotlib version: 2.2.2\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): module://ipykernel.pylab.backend_inline\r\n  * Python version: 3.6.5\r\n  * Jupyter version (if applicable): 5.5.0\r\n  * Other libraries: \r\n\r\n\u003c!--Please tell us how you installed matplotlib and python e.g., from source, pip, conda--\u003e\r\n\u003c!--If you installed from conda, please specify which channel you used if not the default--\u003e\r\nmatplotlib installed from conda default.","author":{"url":"https://github.com/ivankeller","@type":"Person","name":"ivankeller"},"datePublished":"2018-08-20T09:30:55.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":13},"url":"https://github.com/11898/matplotlib/issues/11898"}