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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"xlim is not auto scaled when using twinx","articleBody":"I am reporting as possible bug.\r\n\r\nWhen plotting a secondary y axis on the right, the xlim is not being properly auto scaled. As possible work around was proposed here, https://stackoverflow.com/a/27344398/4988010, however, it seems this was fixed here, https://github.com/matplotlib/matplotlib/commit/26ed35b78cd7542f6841835925be53419661e36e. However, I am not seeing the issue being resolved on matplotlib v3.2.0. \r\n\r\n```python\r\n%matplotlib widget\r\nimport matplotlib.pyplot as plt\r\nimport numpy as np\r\n\r\nfig, ax = plt.subplots()\r\ndecay = lambda C, K, x: C *(1-np.exp(-1*K*x))\r\nx = np.linspace(0,10,10)\r\n\r\n# Create a secondary y axis on the right\r\ntwin_ax = ax.twinx()\r\n\r\nfor n in range(5):\r\n    C = n**2 + 5\r\n    K = 0.75\r\n    # Plot the exponential decay on left y axis \r\n    ax.plot(x,decay(C,K,x), marker='o', linestyle='--', label=C)\r\n    # Plot the limit of decay on right y axis \r\n    twin_ax.axhline(y=C, color='gray') \r\n    \r\nax.legend()\r\nax.set_xlabel('X')\r\nax.set_ylabel('Measured values')\r\ntwin_ax.set_ylabel('Theoritical limit')\r\n\r\n# Align the both left and right y axis \r\ntwin_ax.set_ylim(ax.get_ylim())\r\n\r\n##################\r\n# Issues or bugs\r\n# Need to fix the X limits or else \r\n# the graph doens't display properly\r\n##################\r\n\r\nprint('xlim before fix: {}'.format(ax.get_xlim()))\r\nax.relim()\r\nprint('xlim after relim(): {}'.format(ax.get_xlim()))\r\n# A hack to fix the issue # https://stackoverflow.com/a/27344398/4988010\r\ntwin_ax.plot(0, 0, visible=False)\r\nprint('xlim after fixing: {}'.format(ax.get_xlim()))\r\n\r\nplt.show()\r\n```\r\n![plot with issue](https://imgur.com/nouM1AN.png)\r\n![plot with working hack](https://imgur.com/MqAPF38.png)\r\n","author":{"url":"https://github.com/01baftb","@type":"Person","name":"01baftb"},"datePublished":"2020-03-10T22:27:24.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":7},"url":"https://github.com/16723/matplotlib/issues/16723"}