René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Secondary axis does not show minor ticks.","articleBody":"\r\n\r\n### Bug report\r\n\r\n**Bug summary**\r\n\r\nMatplotlib 3.1 introduced a new method for adding a secondary axes with `Axes.axes.secondary_xaxis` and `Axes.axes.secondary_xaxis`.  However, the `.minorticks_on()` method does nothing on those axes.\r\n\r\n**Code for reproduction**\r\n\r\nI use the example provided in the gallery -- https://matplotlib.org/3.1.0/gallery/subplots_axes_and_figures/secondary_axis.html -- but modify it to show minor ticks.\r\n\r\n```python\r\nimport matplotlib.pyplot as plt\r\nimport numpy as np\r\n\r\nfig, ax = plt.subplots(constrained_layout=True)\r\nx = np.arange(0, 360, 1)\r\ny = np.sin(2 * x * np.pi / 180)\r\nax.plot(x, y)\r\nax.set_xlabel('angle [degrees]')\r\nax.set_ylabel('signal')\r\nax.set_title('Sine wave')\r\n\r\ndef deg2rad(x):\r\n    return x * np.pi / 180\r\n\r\ndef rad2deg(x):\r\n    return x * 180 / np.pi\r\n\r\nsecax = ax.secondary_xaxis('top', functions=(deg2rad, rad2deg))\r\nsecax.set_xlabel('angle [rad]')\r\n\r\nax.minorticks_on()\r\nsecax.minorticks_on()\r\n\r\nplt.show()\r\n```\r\n\r\n**Actual outcome**\r\n\r\n![Screenshot_2019-06-04_19-20-05](https://user-images.githubusercontent.com/4704406/58899654-cdda6280-86fd-11e9-89c8-4bccd08dcce9.png)\r\n\r\n\r\n**Expected outcome**\r\n\r\nThe top axis is expected to have minor ticks.\r\n\r\n**Matplotlib version**\r\n  * Operating system: Linux  4.9.0-9-amd64 #1 SMP Debian 4.9.168-1+deb9u2 (2019-05-13) x86_64 GNU/Linux\r\n  * Matplotlib version: 3.1.0 (conda default channel)\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): TkAgg\r\n  * Python version: Python 3.6.8 |Anaconda custom (64-bit)|\r\n\r\n\r\n\r\n","author":{"url":"https://github.com/Knusper","@type":"Person","name":"Knusper"},"datePublished":"2019-06-04T17:24:16.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/14443/matplotlib/issues/14443"}