matplotlib matplotlib обработка событий для взаимодействия с объектами на холсте

Question

Я использую this code, чтобы нарисовать график связанных точек и перетащить точки свободно на участок. Мне просто нужно изменить цвет заливки полигона от синего до белого. Пожалуйста, сообщите, как это сделать.

import numpy as np 
    from matplotlib.lines import Line2D 
    from matplotlib.artist import Artist 
    from matplotlib.mlab import dist_point_to_segment 

    class PolygonInteractor: 

     showverts = True 
     epsilon = 5 # max pixel distance to count as a vertex hit 

     def __init__(self, ax, poly): 
      if poly.figure is None: 
       raise RuntimeError('You must first add the polygon to a figure or canvas before defining the interactor') 
      self.ax = ax 
      canvas = poly.figure.canvas 
      self.poly = poly 

      x, y = zip(*self.poly.xy) 
      self.line = Line2D(x, y, marker='o', markerfacecolor='r', animated=True) 
      self.ax.add_line(self.line) 
      #self._update_line(poly) 

      cid = self.poly.add_callback(self.poly_changed) 
      self._ind = None # the active vert 

      canvas.mpl_connect('draw_event', self.draw_callback) 
      canvas.mpl_connect('button_press_event', self.button_press_callback) 
      canvas.mpl_connect('key_press_event', self.key_press_callback) 
      canvas.mpl_connect('button_release_event', self.button_release_callback) 
      canvas.mpl_connect('motion_notify_event', self.motion_notify_callback) 
      self.canvas = canvas 


     def draw_callback(self, event): 
      self.background = self.canvas.copy_from_bbox(self.ax.bbox) 
      self.ax.draw_artist(self.poly) 
      self.ax.draw_artist(self.line) 
      self.canvas.blit(self.ax.bbox) 

     def poly_changed(self, poly): 
      'this method is called whenever the polygon object is called' 
      # only copy the artist props to the line (except visibility) 
      vis = self.line.get_visible() 
      Artist.update_from(self.line, poly) 
      self.line.set_visible(vis) # don't use the poly visibility state 


     def get_ind_under_point(self, event): 
      'get the index of the vertex under point if within epsilon tolerance' 

      # display coords 
      xy = np.asarray(self.poly.xy) 
      xyt = self.poly.get_transform().transform(xy) 
      xt, yt = xyt[:, 0], xyt[:, 1] 
      d = np.sqrt((xt-event.x)**2 + (yt-event.y)**2) 
      indseq = np.nonzero(np.equal(d, np.amin(d)))[0] 
      ind = indseq[0] 

      if d[ind]>=self.epsilon: 
       ind = None 

      return ind 

     def button_press_callback(self, event): 
      'whenever a mouse button is pressed' 
      if not self.showverts: return 
      if event.inaxes==None: return 
      if event.button != 1: return 
      self._ind = self.get_ind_under_point(event) 

     def button_release_callback(self, event): 
      'whenever a mouse button is released' 
      if not self.showverts: return 
      if event.button != 1: return 
      self._ind = None 

     def key_press_callback(self, event): 
      'whenever a key is pressed' 
      if not event.inaxes: return 
      if event.key=='t': 
       self.showverts = not self.showverts 
       self.line.set_visible(self.showverts) 
       if not self.showverts: self._ind = None 
      elif event.key=='d': 
       ind = self.get_ind_under_point(event) 
       if ind is not None: 
        self.poly.xy = [tup for i,tup in enumerate(self.poly.xy) if i!=ind] 
        self.line.set_data(zip(*self.poly.xy)) 
      elif event.key=='i': 
       xys = self.poly.get_transform().transform(self.poly.xy) 
       p = event.x, event.y # display coords 
       for i in range(len(xys)-1): 
        s0 = xys[i] 
        s1 = xys[i+1] 
        d = dist_point_to_segment(p, s0, s1) 
        if d<=self.epsilon: 
         self.poly.xy = np.array(
          list(self.poly.xy[:i]) + 
          [(event.xdata, event.ydata)] + 
          list(self.poly.xy[i:])) 
         self.line.set_data(zip(*self.poly.xy)) 
         break 


      self.canvas.draw() 

     def motion_notify_callback(self, event): 
      'on mouse movement' 
      if not self.showverts: return 
      if self._ind is None: return 
      if event.inaxes is None: return 
      if event.button != 1: return 
      x,y = event.xdata, event.ydata 

      self.poly.xy[self._ind] = x,y 
      self.line.set_data(zip(*self.poly.xy)) 

      self.canvas.restore_region(self.background) 
      self.ax.draw_artist(self.poly) 
      self.ax.draw_artist(self.line) 
      self.canvas.blit(self.ax.bbox) 


    if __name__ == '__main__': 
     import matplotlib.pyplot as plt 
     from matplotlib.patches import Polygon 

     theta = np.arange(0, 2*np.pi, 0.1) 
     r = 1.5 

     xs = r*np.cos(theta) 
     ys = r*np.sin(theta) 

     poly = Polygon(list(zip(xs, ys)), animated=True) 

     fig, ax = plt.subplots() 
     ax.add_patch(poly) 
     p = PolygonInteractor(ax, poly) 

     #ax.add_line(p.line) 
     ax.set_title('Click and drag a point to move it') 
     ax.set_xlim((-2,2)) 
     ax.set_ylim((-2,2)) 
     plt.show() 

Answer 1

Использование facecolor='white' для заполнения многоугольников с белым:

poly = Polygon(list(zip(xs, ys)), animated=True, facecolor='white') 

или использовать fill=False оставить интерьер прозрачным.

poly = Polygon(list(zip(xs, ys)), animated=True, fill=False)