spline interpolation and draw image by matplotlib 


 1 # spline interpolation and draw image by matplotlib
 2 
 3 from scipy import interpolate
 4 import matplotlib.pyplot as plt
 5 
 6 #prepare data of globe 
 7 x_g = [0, 1, 2, 3, 4, 5]
 8 y_g = [12,14,22,39,58,77]
 9 
10 x_points=x_g.copy()
11 y_points=y_g.copy()
12 
13 # spline interpolation
14 def f(x):
15     tck = interpolate.splrep(x_points, y_points)
16     return interpolate.splev(x, tck)
17 
18 # a test point  1.25/ ret=f(1.25)
19 p1=f(1.25)
20 print(p1.tolist()) # ndarray to list
21 x_g.append(1.25)
22 y_g.append(p1.tolist())
23 
24 # another test point  [2.6,3.1,4.5]/ ret=f(m)
25 m=[2.6,3.1,4.5]
26 n=f(m)
27 print(f(m))
28 x_g.extend(m)
29 y_g.extend(n)
30 
31 x_g.sort()
32 y_g.sort()
33 plt.plot(x_g,y_g)
34 plt.gray()
35 plt.grid(True)
36 
37 # add label for each point
38 for i in range(1,len(x_g)):
39     plt.text(x_g[i],y_g[i],str([x_g[i],y_g[i]]), family='serif', style='italic', ha='right', wrap=True)
40 
41 plt.show()
42

 

posted on 2018-02-28 14:20  rojas  阅读(196)  评论(0)    收藏  举报