如何旋转绘制的数据？

Question

请问如何将绘制的曲线旋转90度？可不可以设置ax.plot(x,y,z)的结果旋转90度左右？谢谢

import matplotlib as mpl
from mpl_toolkits.mplot3d import Axes3D
import numpy as np
import matplotlib.pyplot as plt

mpl.rcParams['legend.fontsize'] = 10

fig = plt.figure()
ax = fig.gca(projection='3d')
theta = np.linspace(-4 * np.pi, 4 * np.pi, 100)
z = np.linspace(-2, 2, 100)
r = z**2 + 1
x = r * np.sin(theta)
y = r * np.cos(theta)
ax.plot(x, y, z, label='parametric curve')
plt.show()

Answer 1

我建议你看看旋转矩阵。来自维基百科的 topic 是一个好的开始！让我们来实现它：

我们可以根据3个轴进行3次旋转。

工作流程:

首先，一定要处理好弧度角。
其次，我们需要实现旋转矩阵
然后我们使用 numpy.dot

np.array([np.dot(rotation_matrix, vect) for vect in zip(X, Y, Z)])

最后绘制结果

完整代码:

# Modules
from mpl_toolkits.mplot3d import Axes3D
import numpy as np
import matplotlib.pyplot as plt
from math import cos, sin, pi

# Input angles
angle_x = 90
angle_y = 90
angle_z = 90

# Conversion radian
theta_x = angle_x*pi/180
theta_y = angle_y*pi/180
theta_z = angle_z*pi/180

# rotation matrix
R_x = np.array([[1, 0           ,  0           ],
                [0, cos(theta_x), -sin(theta_x)],
                [0, sin(theta_x),  cos(theta_x)]])
R_y = np.array([[ cos(theta_y), 0, sin(theta_y)],
                [ 0           , 1, 0           ],
                [-sin(theta_y), 0, cos(theta_y)]])
R_z = np.array([[cos(theta_z), -sin(theta_z), 0],
                [sin(theta_z),  cos(theta_z), 0],
                [0           ,  0           , 1]])

# Compute initial curve
theta = np.linspace(-4 * np.pi, 4 * np.pi, 100)
Z = np.linspace(-2, 2, 100)
r = Z**2 + 1
X = r * np.sin(theta)
Y = r * np.cos(theta)

# Compute rotation
rotated_x = np.array([np.dot(R_x, vect) for vect in zip(X, Y, Z)])
rotated_y = np.array([np.dot(R_y, vect) for vect in zip(X, Y, Z)])
rotated_z = np.array([np.dot(R_z, vect) for vect in zip(X, Y, Z)])

# Extras for plotting
def addExtras(ax):
    ax.plot(X, Y, Z, label='Initial curve')
    ax.set_xlabel('X Axis')
    ax.set_ylabel('Y Axis')
    ax.set_zlabel('Z Axis')
    plt.legend()

# Create figure
fig = plt.figure()

# Create subplots 
ax = fig.add_subplot(2, 2, 1, projection='3d')
addExtras(ax)

ax = fig.add_subplot(2, 2, 2, projection='3d')
ax.plot(rotated_x[:, 0], rotated_x[:, 1], rotated_x[:, 2], label='X+90° rotation curve')
addExtras(ax)

ax = fig.add_subplot(2, 2, 3, projection='3d')
ax.plot(rotated_y[:, 0], rotated_y[:, 1], rotated_y[:, 2], label='Y+90° rotation curve')
addExtras(ax)

ax = fig.add_subplot(2, 2, 4, projection='3d')
ax.plot(rotated_z[:, 0], rotated_z[:, 1], rotated_z[:, 2], label='Z+90° rotation curve')
addExtras(ax)

# Show results
plt.show()

输出

如何旋转绘制的数据？

How to rotate plotted data?

matplotlib

rotation

python-3.x