René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"nbagg backend incredibly laggy in IPython notebook","articleBody":"- [ ] Matplotlib version, Python version and Platform (Windows, OSX, Linux ...)\n  Windows 10, Matplotlib 1.5.1, Python 3.5.2\n\nI wrote some code for allowing the user to draw rectangles in a blank matplotlib graph using the nbagg backend in an IPython notebook, and it is incredibly laggy. Is this a current limitation, or is this perhaps a bug with the library? Here is the code I have:\n\n```\nimport matplotlib\nmatplotlib.use(\"nbagg\")\nimport matplotlib.pyplot as plt\nfrom matplotlib.patches import Rectangle\nfrom ipywidgets.widgets import Button\nfrom IPython.display import display\n\nclass Test(object):\n    def __init__(self):\n        plt.ion()\n        self.figure = plt.figure()\n        self.ax = self.figure.gca()\n        self.rect = Rectangle((0,0), 0, 0, color = '0', fill = False)\n        self.x0 = None\n        self.y0 = None\n        self.x1 = None\n        self.y1 = None\n        # Graph interaction\n        self.ax.add_patch(self.rect)\n        self.ax.figure.canvas.mpl_connect('button_press_event', self.on_press)\n        self.ax.figure.canvas.mpl_connect('button_release_event', self.on_release)\n        self.ax.figure.canvas.mpl_connect('motion_notify_event', self.on_motion)\n\n    def on_motion(self, event):\n        if self.is_pressed:\n            self.x1 = event.xdata\n            self.y1 = event.ydata\n\n            self.rect.set_width(self.x1 - self.x0)\n            self.rect.set_height(self.y1 - self.y0)\n            self.rect.set_xy((self.x0, self.y0))\n            self.rect.figure.canvas.draw()\n\n    def on_press(self, event):\n        self.is_pressed = 1\n        self.x0 = event.xdata\n        self.y0 = event.ydata\n        self.rect.set_visible(True)\n\n    def on_release(self, event):\n        self.is_pressed = 0\n        self.ax.scatter(self.x_inside, self.y_inside, c = \"red\")\n        self.figure.canvas.draw()\n        self.rect.set_visible(False)\n        self.rect.figure.canvas.draw()\n\n\ntest = Test()\n```\n","author":{"url":"https://github.com/alexanderwhatley","@type":"Person","name":"alexanderwhatley"},"datePublished":"2016-07-28T05:45:03.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/6850/matplotlib/issues/6850"}