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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Matplotlib colorbar moves second x axis drawn with twiny","articleBody":"Bug report originated in SO post here: http://stackoverflow.com/q/34979781/1391441\n\n---\n\nI'm trying to add a second x axis to the top of a plot using [twiny](http://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.twiny).\n\nIf I make a simple scatter plot with no colorbar, the top x axis is correctly aligned with the bottom x axis (MWE is below):\n\n[![enter image description here](http://i.stack.imgur.com/NPT2H.png)](http://i.stack.imgur.com/NPT2H.png)\n\nIf I add a colorbar though, the top x axis is displaced:\n\n[![enter image description here](http://i.stack.imgur.com/5yf97.png)](http://i.stack.imgur.com/5yf97.png)\n\n---\n\n**MWE**\n\n```\nimport numpy as np\nimport matplotlib.pyplot as plt\nfrom mpl_toolkits.axes_grid1 import make_axes_locatable\nimport matplotlib.gridspec as gridspec\n\n\nX = np.array([0., 0.5, 1., 1.5, 2., 2.5, 3., 3.5, 4.])\nX2 = np.array([122, 85, 63, 50, 23, 12, 7, 5, 2])\nY = np.cos(X*20)\nZ = np.sin(X*20)\n\nfig = plt.figure()\ngs = gridspec.GridSpec(1, 2)\nax1 = plt.subplot(gs[1])\nax2 = ax1.twiny()\n\nax1.set_xlim(-0.2, max(X)+0.2)\nplt.tick_params(axis='both', which='major', labelsize=10)\nax1.minorticks_on()\nax1.grid(b=True, which='major', color='gray', linestyle='--', lw=0.3)\n\nSC = ax1.scatter(X, Y, c=Z)\nax1.set_xlabel(\"Original x-axis\")\n\nax2.set_xlim(ax1.get_xlim())\nax2.set_xticks(X)\nax2.set_xticklabels(X2)\nax2.set_xlabel(\"Second x-axis\")\n\n# Colorbar.\nthe_divider = make_axes_locatable(ax1)\ncolor_axis = the_divider.append_axes(\"right\", size=\"2%\", pad=0.1)\ncbar = plt.colorbar(SC, cax=color_axis)\ncbar.set_label('B', fontsize=10, labelpad=4, y=0.5)\ncbar.ax.tick_params(labelsize=10)\n\nplt.show()\n```\n","author":{"url":"https://github.com/Gabriel-p","@type":"Person","name":"Gabriel-p"},"datePublished":"2016-01-24T23:37:15.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/5904/matplotlib/issues/5904"}