事件处理matplotlip python

Question

我想从图中选取并绘制点，并在数组中存储它们的坐标。那可能吗？如果是的话，你可以帮助引导我，谢谢你的帮助。

我有这样的例子，但它是画线：

from matplotlib import pyplot as plt 

class LineBuilder: 
    def __init__(self, line): 
     self.line = line 
     self.xs = list(line.get_xdata()) 
     self.ys = list(line.get_ydata()) 
     self.cid = line.figure.canvas.mpl_connect('button_press_event', self) 

    def __call__(self, event): 
     print('click', event) 
     if event.inaxes!=self.line.axes: return 
     self.xs.append(event.xdata) 
     self.ys.append(event.ydata) 
     self.line.set_data(self.xs, self.ys) 
     self.line.figure.canvas.draw() 
fig = plt.figure() 
ax = fig.add_subplot(111) 
ax.set_title('click to build line segments') 
line, = ax.plot([0], [0]) # empty line 
linebuilder = LineBuilder(line) 
plt.show() 

Answer 1

首先，为了吸引点，而不是一条线，你需要定义一个标记，可选择性地开启线断：

line, = ax.plot([0], [0], marker="o", linestyle="") 

坐标已存储在阵列LineBuilder.xs和LineBuilder.xs中，因此您可以将它们打印出来。

完整的示例：

from matplotlib import pyplot as plt 

class LineBuilder: 
    def __init__(self, line): 
     self.line = line 
     self.xs = list(line.get_xdata()) 
     self.ys = list(line.get_ydata()) 
     self.cid = line.figure.canvas.mpl_connect('button_press_event', self) 

    def __call__(self, event): 
     if event.inaxes!=self.line.axes: return 
     self.xs.append(event.xdata) 
     self.ys.append(event.ydata) 
     self.line.set_data(self.xs, self.ys) 
     self.line.figure.canvas.draw_idle() 
     print(self.xs) 
     print(self.ys) 

fig = plt.figure() 
ax = fig.add_subplot(111) 
ax.set_title('click to build line segments') 
line, = ax.plot([0], [0], marker="o", linestyle="") 
linebuilder = LineBuilder(line) 
plt.show()