MeteoInfoLab脚本示例：调整坐标轴位置

MeteoInfo

MeteoInfoLab里坐标轴的设置用 xaxis 和 yaxis 函数，position参数（tuple，包括位置类型和值）可以调整坐标轴的位置，支持的位置类型为：'outerward', 'axes', 'data'。比如要将 x 坐标轴放在y数据0位置上：xaxis(position=('data', 0)) 。下面的例子只显示左和下坐标轴，坐标轴的位置调整到数据0值。

1. X = np.linspace(-np.pi, np.pi, 256, endpoint=True)
   
2. C = np.cos(X)
   
3. S = np.sin(X)
   
4. t = 2 * np.pi / 3
   
5. 
   
6. plt.axes(outerposition=[0,0,1,1])
   
7. lcosine = plt.plot(X, C, color='blue', linewidth=2.5, linestyle='-', label='cosine')
   
8. plt.plot([t,t],[0,np.cos(t)], color='blue', linewidth=2.5, linestyle="--")
   
9. plt.scatter([t,],[np.cos(t),], s=6, color ='blue', edgecolor=None)
   
10. plt.annotate(r'$\rm cos(\frac{2\pi}{3})=-\frac{1}{2}$',
    
11.          (t, np.cos(t)), (t*0.5, np.cos(t)-0.2), fontsize=18, xalign='center',
    
12.          yalign='top',
    
13.          arrowprops=dict(linewidth=1, headwidth=8, shrink=0.05, overhang=1))
    
14. 
    
15. lsine = plt.plot(X, S, color='red', linewidth=2.5, linestyle='-', label='sine')
    
16. plt.plot([t,t],[0,np.sin(t)], color='red', linewidth=2.5, linestyle="--")
    
17. plt.scatter([t,],[np.sin(t),], s=6, c='red', edgecolor=None)
    
18. plt.annotate(r'$\rm sin(\frac{2\pi}{3})=\frac{\sqrt{3}}{2}$',
    
19.          (t, np.sin(t)), (t+0.1, np.sin(t)+0.2), fontsize=18, xalign='left',
    
20.          arrowprops=dict(linewidth=1, headwidth=8, shrink=0.05, overhang=1))
    
21. 
    
22. plt.xaxis(location='top', visible=False)
    
23. plt.xaxis(location='bottom', position=('data',0))
    
24. plt.yaxis(location='right', visible=False)
    
25. plt.yaxis(location='left', position=('data',0))
    
26. 
    
27. plt.xlim(X.min() * 1.3, X.max() * 1.3)
    
28. plt.xticks([-np.pi, -np.pi/2, 0, np.pi/2, np.pi],
    
29.   [r'$-\pi$', r'$-\pi/2$', r'$0$', r'$+\pi/2$', r'$+\pi$'])
    
30. 
    
31. plt.ylim(C.min() * 1.3, C.max() * 1.3)
    
32. plt.yticks([-1, 0, +1], [r'$-1$', r'$0$', r'$+1$'])
    
33. 
    
34. plt.legend([lcosine, lsine], loc='upper left')

X = np.linspace(-np.pi, np.pi, 256, endpoint=True)<br /> C = np.cos(X)<br /> S = np.sin(X)<br /> t = 2 * np.pi / 3<br /> <br /> plt.axes(outerposition=[0,0,1,1])<br /> lcosine = plt.plot(X, C, color='blue', linewidth=2.5, linestyle='-', label='cosine')<br /> plt.plot([t,t],[0,np.cos(t)], color='blue', linewidth=2.5, linestyle="--")<br /> plt.scatter([t,],[np.cos(t),], s=6, color ='blue', edgecolor=None)<br /> plt.annotate(r'$\rm cos(\frac{2\pi}{3})=-\frac{1}{2}$',<br />          (t, np.cos(t)), (t*0.5, np.cos(t)-0.2), fontsize=18, xalign='center',<br />          yalign='top',<br />          arrowprops=dict(linewidth=1, headwidth=8, shrink=0.05, overhang=1))<br /> <br /> lsine = plt.plot(X, S, color='red', linewidth=2.5, linestyle='-', label='sine')<br /> plt.plot([t,t],[0,np.sin(t)], color='red', linewidth=2.5, linestyle="--")<br /> plt.scatter([t,],[np.sin(t),], s=6, c='red', edgecolor=None)<br /> plt.annotate(r'$\rm sin(\frac{2\pi}{3})=\frac{\sqrt{3}}{2}$',<br />          (t, np.sin(t)), (t+0.1, np.sin(t)+0.2), fontsize=18, xalign='left',<br />          arrowprops=dict(linewidth=1, headwidth=8, shrink=0.05, overhang=1))<br /> <br /> plt.xaxis(location='top', visible=False)<br /> plt.xaxis(location='bottom', position=('data',0))<br /> plt.yaxis(location='right', visible=False)<br /> plt.yaxis(location='left', position=('data',0))<br /> <br /> plt.xlim(X.min() * 1.3, X.max() * 1.3)<br /> plt.xticks([-np.pi, -np.pi/2, 0, np.pi/2, np.pi],<br />   [r'$-\pi$', r'$-\pi/2$', r'$0$', r'$+\pi/2$', r'$+\pi$'])<br /> <br /> plt.ylim(C.min() * 1.3, C.max() * 1.3)<br /> plt.yticks([-1, 0, +1], [r'$-1$', r'$0$', r'$+1$'])<br /> <br /> plt.legend([lcosine, lsine], loc='upper left')