Python Matplotlib.patches.Arrow用法及代码示例

import matplotlib.pyplot as plt 
import numpy as np 
import matplotlib.path as mpath 
import matplotlib.lines as mlines 
import matplotlib.patches as mpatches 
from matplotlib.collections import PatchCollection 
  
  
def label(xy, text):
      
    # shift y-value for label so that  
    # it's below the artist 
    y = xy[1] - 0.15
    plt.text(xy[0], y, text, ha ="center", 
             family ='sans-serif', size = 14) 
  
  
fig, ax = plt.subplots() 
  
# create 3x3 grid to plot  
# the artists 
grid = np.mgrid[0.2:0.8:3j,  
                0.2:0.8:3j].reshape(2, -1).T 
  
patches = [] 
  
  
# add an arrow 
arrow = mpatches.Arrow(grid[5, 0] - 0.05,  
                       grid[5, 1] - 0.05, 0.1, 0.1, 
                       width = 0.1) 
patches.append(arrow) 
label(grid[5], " Sample Arrow") 
  
  
colors = np.linspace(0, 1, len(patches)) 
collection = PatchCollection(patches, 
                             cmap = plt.cm.hsv,  
                             alpha = 0.3) 
  
collection.set_array(np.array(colors)) 
ax.add_collection(collection) 
  
plt.axis('equal') 
plt.axis('off') 
plt.tight_layout() 
  
plt.show()

from matplotlib import pyplot as plt 
from matplotlib.patches import Rectangle, Arrow 
import numpy as np 
  
  
nmax = 9
xdata = range(nmax) 
ydata = np.random.random(nmax) 
  
plt.ion() 
fig, ax = plt.subplots() 
ax.set_aspect("equal") 
ax.plot(xdata, ydata, 'o-') 
ax.set_xlim(-1, 10) 
ax.set_ylim(-1, 4) 
  
  
rect = Rectangle((0, 0), nmax, 1, zorder = 10) 
ax.add_patch(rect) 
  
x0, y0 = 5, 3
arrow = Arrow(1, 1, x0-1, y0-1, color ="# aa0088") 
  
a = ax.add_patch(arrow) 
  
plt.draw() 
  
for i in range(nmax):
      
    rect.set_x(i) 
    rect.set_width(nmax - i) 
  
    a.remove() 
    arrow = Arrow(1 + i, 1, x0-i + 1, y0-1,  
                  color ="# aa0088") 
    a = ax.add_patch(arrow) 
  
    fig.canvas.draw_idle() 
    plt.pause(0.4) 
  
plt.waitforbuttonpress()  
  
plt.show()