| """ |
| ============= |
| Looking Glass |
| ============= |
| |
| Example using mouse events to simulate a looking glass for inspecting data. |
| |
| .. note:: |
| This example exercises the interactive capabilities of Matplotlib, and this |
| will not appear in the static documentation. Please run this code on your |
| machine to see the interactivity. |
| |
| You can copy and paste individual parts, or download the entire example |
| using the link at the bottom of the page. |
| """ |
| import matplotlib.pyplot as plt |
| import numpy as np |
|
|
| import matplotlib.patches as patches |
|
|
| |
| np.random.seed(19680801) |
|
|
| x, y = np.random.rand(2, 200) |
|
|
| fig, ax = plt.subplots() |
| circ = patches.Circle((0.5, 0.5), 0.25, alpha=0.8, fc='yellow') |
| ax.add_patch(circ) |
|
|
|
|
| ax.plot(x, y, alpha=0.2) |
| line, = ax.plot(x, y, alpha=1.0, clip_path=circ) |
| ax.set_title("Left click and drag to move looking glass") |
|
|
|
|
| class EventHandler: |
| def __init__(self): |
| fig.canvas.mpl_connect('button_press_event', self.on_press) |
| fig.canvas.mpl_connect('button_release_event', self.on_release) |
| fig.canvas.mpl_connect('motion_notify_event', self.on_move) |
| self.x0, self.y0 = circ.center |
| self.pressevent = None |
|
|
| def on_press(self, event): |
| if event.inaxes != ax: |
| return |
|
|
| if not circ.contains(event)[0]: |
| return |
|
|
| self.pressevent = event |
|
|
| def on_release(self, event): |
| self.pressevent = None |
| self.x0, self.y0 = circ.center |
|
|
| def on_move(self, event): |
| if self.pressevent is None or event.inaxes != self.pressevent.inaxes: |
| return |
|
|
| dx = event.xdata - self.pressevent.xdata |
| dy = event.ydata - self.pressevent.ydata |
| circ.center = self.x0 + dx, self.y0 + dy |
| line.set_clip_path(circ) |
| fig.canvas.draw() |
|
|
| handler = EventHandler() |
| plt.show() |
|
|
