用python写一段代码 实现旋转矩阵到rx，ry，rz的转化

在Python中，你可以使用NumPy库来方便地处理矩阵变换。这里是一个简单的例子，展示如何创建一个函数来实现绕X、Y、Z轴的旋转矩阵（Rx, Ry, Rz）。首先，你需要安装NumPy如果还没有的话，可以使用pip install numpy。

import numpy as np

def rotation_matrix(axis, theta):
    """
    Generate a rotation matrix given an axis and angle.

    Parameters:
    axis (list): A unit vector representing the axis of rotation.
    theta (float): The angle of rotation in radians.

    Returns:
    np.ndarray: A 3x3 rotation matrix.
    """
    axis = axis / np.linalg.norm(axis)  # Normalize the axis
    a, b, c = axis
    cos_t = np.cos(theta)
    sin_t = np.sin(theta)

    # Create the rotation matrix
    R = np.array([[cos_t + a**2 * (1 - cos_t),     a * b * (1 - cos_t) - c * sin_t,     a * c * (1 - cos_t) + b * sin_t],
                  [b * a * (1 - cos_t) + c * sin_t, cos_t + b**2 * (1 - cos_t),     b * c * (1 - cos_t) - a * sin_t],
                  [c * a * (1 - cos_t) - b * sin_t, c * b * (1 - cos_t) + a * sin_t, cos_t + c**2 * (1 - cos_t)]])
    
    return R

# Example usage: Rotate a matrix around X, Y, or Z axes
matrix = np.eye(3)  # Your input matrix
rotated_x = rotation_matrix([1, 0, 0], np.pi/4)  # 45-degree rotation around X
rotated_y = rotation_matrix([0, 1, 0], np.pi/2)   # 90-degree rotation around Y
rotated_z = rotation_matrix([0, 0, 1], np.pi/3)  # 60-degree rotation around Z

print("Rotation around X:")
print(rotated_x @ matrix)
print("\nRotation around Y:")
print(rotated_y @ matrix)
print("\nRotation around Z:")
print(rotated_z @ matrix)