.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "gallery/event_handling/lasso_demo.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. meta:: :keywords: codex .. note:: :class: sphx-glr-download-link-note :ref:`Go to the end ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_gallery_event_handling_lasso_demo.py: ========== Lasso Demo ========== Use a lasso to select a set of points and get the indices of the selected points. A callback is used to change the color of the selected points. .. 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. .. GENERATED FROM PYTHON SOURCE LINES 17-67 .. image-sg:: /gallery/event_handling/images/sphx_glr_lasso_demo_001.png :alt: Lasso points using left mouse button :srcset: /gallery/event_handling/images/sphx_glr_lasso_demo_001.png, /gallery/event_handling/images/sphx_glr_lasso_demo_001_2_00x.png 2.00x :class: sphx-glr-single-img .. code-block:: Python import matplotlib.pyplot as plt import numpy as np from matplotlib import colors as mcolors from matplotlib import path from matplotlib.collections import RegularPolyCollection from matplotlib.widgets import Lasso class LassoManager: def __init__(self, ax, data): # The information of whether a point has been selected or not is stored in the # collection's array (0 = out, 1 = in), which then gets colormapped to blue # (out) and red (in). self.collection = RegularPolyCollection( 6, sizes=(100,), offset_transform=ax.transData, offsets=data, array=np.zeros(len(data)), clim=(0, 1), cmap=mcolors.ListedColormap(["tab:blue", "tab:red"])) ax.add_collection(self.collection) canvas = ax.figure.canvas canvas.mpl_connect('button_press_event', self.on_press) canvas.mpl_connect('button_release_event', self.on_release) def callback(self, verts): data = self.collection.get_offsets() self.collection.set_array(path.Path(verts).contains_points(data)) canvas = self.collection.figure.canvas canvas.draw_idle() del self.lasso def on_press(self, event): canvas = self.collection.figure.canvas if event.inaxes is not self.collection.axes or canvas.widgetlock.locked(): return self.lasso = Lasso(event.inaxes, (event.xdata, event.ydata), self.callback) canvas.widgetlock(self.lasso) # acquire a lock on the widget drawing def on_release(self, event): canvas = self.collection.figure.canvas if hasattr(self, 'lasso') and canvas.widgetlock.isowner(self.lasso): canvas.widgetlock.release(self.lasso) if __name__ == '__main__': np.random.seed(19680801) ax = plt.figure().add_subplot( xlim=(0, 1), ylim=(0, 1), title='Lasso points using left mouse button') manager = LassoManager(ax, np.random.rand(100, 2)) plt.show() .. _sphx_glr_download_gallery_event_handling_lasso_demo.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: lasso_demo.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: lasso_demo.py ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_