“Ellipse”的版本间差异
| 无编辑摘要 | 无编辑摘要 | ||
| 第4行: | 第4行: | ||
| 	from matplotlib import pyplot as plt | 	from matplotlib import pyplot as plt | ||
| 	from math import pi, cos, sin | 	from math import pi, cos, sin | ||
|         ### | |||
| 	u=1.       #x-position of the center | 	u=1.       #x-position of the center | ||
| 	v=0.5      #y-position of the center | 	v=0.5      #y-position of the center | ||
| 第10行: | 第10行: | ||
| 	b=1.5      #radius on the y-axis | 	b=1.5      #radius on the y-axis | ||
| 	t_rot=pi/4 #rotation angle | 	t_rot=pi/4 #rotation angle | ||
|         ### | |||
| 	t = np.linspace(0, 2*pi, 100) | 	t = np.linspace(0, 2*pi, 100) | ||
| 	Ell = np.array([a*np.cos(t) , b*np.sin(t)])   | 	Ell = np.array([a*np.cos(t) , b*np.sin(t)])   | ||
| 第16行: | 第16行: | ||
| 	R_rot = np.array([[cos(t_rot) , -sin(t_rot)],[sin(t_rot) , cos(t_rot)]])   | 	R_rot = np.array([[cos(t_rot) , -sin(t_rot)],[sin(t_rot) , cos(t_rot)]])   | ||
| 		 #2-D rotation matrix | 		 #2-D rotation matrix | ||
|         ### | |||
| 	Ell_rot = np.zeros((2,Ell.shape[1])) | 	Ell_rot = np.zeros((2,Ell.shape[1])) | ||
| 	for i in range(Ell.shape[1]): | 	for i in range(Ell.shape[1]): | ||
| 		Ell_rot[:,i] = np.dot(R_rot,Ell[:,i]) | 		Ell_rot[:,i] = np.dot(R_rot,Ell[:,i]) | ||
|         ### | |||
| 	plt.plot( u+Ell[0,:] , v+Ell[1,:] )     #initial ellipse | 	plt.plot( u+Ell[0,:] , v+Ell[1,:] )     #initial ellipse | ||
| 	plt.plot( u+Ell_rot[0,:] , v+Ell_rot[1,:],'darkorange' )    #rotated ellipse | 	plt.plot( u+Ell_rot[0,:] , v+Ell_rot[1,:],'darkorange' )    #rotated ellipse | ||
2019年6月27日 (四) 03:32的版本
python code
import numpy as np from matplotlib import pyplot as plt from math import pi, cos, sin
###
u=1. #x-position of the center v=0.5 #y-position of the center a=2. #radius on the x-axis b=1.5 #radius on the y-axis t_rot=pi/4 #rotation angle
###
t = np.linspace(0, 2*pi, 100) Ell = np.array([a*np.cos(t) , b*np.sin(t)]) #u,v removed to keep the same center location R_rot = np.array([[cos(t_rot) , -sin(t_rot)],[sin(t_rot) , cos(t_rot)]]) #2-D rotation matrix
###
Ell_rot = np.zeros((2,Ell.shape[1])) for i in range(Ell.shape[1]): Ell_rot[:,i] = np.dot(R_rot,Ell[:,i])
###
plt.plot( u+Ell[0,:] , v+Ell[1,:] ) #initial ellipse plt.plot( u+Ell_rot[0,:] , v+Ell_rot[1,:],'darkorange' ) #rotated ellipse plt.grid(color='lightgray',linestyle='--') plt.show()