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:
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:
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()
案例的關鍵代碼在于LassoManager類的onpress方法和callback方法。由于Lasso類在事件處理上比較原始，需要用戶進行控制，在鼠標按下、釋放事件中需要使用canvas.widgetlock對象鎖定/解鎖繪圖功能，保證只有一個對象進行繪圖，canvas.widgetlock是matplotlib.widgets.LockDraw類的實例。
盡量使用套索選區（LassoSelector）而不是套索（Lasso），兩者功能相似，索選區（LassoSelector）使用相對更簡單一些，套索（Lasso）還有一些BUG，matplotlib 3.3已不再推薦使用。
到此這篇關于matplotlib部件之套索Lasso的使用的文章就介紹到這了,更多相關matplotlib 套索內容請搜索腳本之家以前的文章或繼續瀏覽下面的相關文章希望大家以后多多支持腳本之家！
