套索演示
演示如何使用套索选择一组点并获取所选点的索引。回调用于更改所选点的颜色。
这是一个概念验证实现（尽管它可以按原样使用）。将对API进行一些改进。
from matplotlib import colors as mcolors, path
from matplotlib.collections import RegularPolyCollection
import matplotlib.pyplot as plt
from matplotlib.widgets import Lasso
import numpy as np
class Datum(object):
colorin = mcolors.to_rgba("red")
colorout = mcolors.to_rgba("blue")
def __init__(self, x, y, include=False):
self.x = x
self.y = y
if include:
self.color = self.colorin
else:
self.color = self.colorout
class LassoManager(object):
def __init__(self, ax, data):
self.axes = ax
self.canvas = ax.figure.canvas
self.data = data
self.Nxy = len(data)
facecolors = [d.color for d in data]
self.xys = [(d.x, d.y) for d in data]
self.collection = RegularPolyCollection(
6, sizes=(100,),
facecolors=facecolors,
offsets=self.xys,
transOffset=ax.transData)
ax.add_collection(self.collection)
self.cid = self.canvas.mpl_connect('button_press_event', self.onpress)
def callback(self, verts):
facecolors = self.collection.get_facecolors()
p = path.Path(verts)
ind = p.contains_points(self.xys)
for i in range(len(self.xys)):
if ind[i]:
facecolors[i] = Datum.colorin
else:
facecolors[i] = Datum.colorout
self.canvas.draw_idle()
self.canvas.widgetlock.release(self.lasso)
del self.lasso
def onpress(self, event):
if self.canvas.widgetlock.locked():
return
if event.inaxes is None:
return
self.lasso = Lasso(event.inaxes,
(event.xdata, event.ydata),
self.callback)
# acquire a lock on the widget drawing
self.canvas.widgetlock(self.lasso)
if __name__ == '__main__':
np.random.seed(19680801)
data = [Datum(*xy) for xy in np.random.rand(100, 2)]
ax = plt.axes(xlim=(0, 1), ylim=(0, 1), autoscale_on=False)
ax.set_title('Lasso points using left mouse button')
lman = LassoManager(ax, data)
plt.show()