pyquaternion: ValueError: Unexpected number of elements in sequence

Question

使用 pyquaternion module 我想获得 3x3 旋转矩阵的四元数表示。执行时，它 returns ValueError: Unexpected number of elements in sequence. Got: 3, Expected: 4.。根据文档，用 3x3 矩阵实例化四元数应该可行，或者我可能误解了一些东西。

为了测试这个，我发现这个 method 用于随机旋转矩阵生成。如上所述，我只收到此错误消息。

import numpy as np
from pyquaternion import Quaternion

def rand_rotation_matrix(deflection=1.0, randnums=None):
    """
    Creates a random rotation matrix.

    deflection: the magnitude of the rotation. For 0, no rotation; for 1, competely random
    rotation. Small deflection => small perturbation.
    randnums: 3 random numbers in the range [0, 1]. If `None`, they will be auto-generated.
    """
    # from http://www.realtimerendering.com/resources/GraphicsGems/gemsiii/rand_rotation.c

    if randnums is None:
        randnums = np.random.uniform(size=(3,))

    theta, phi, z = randnums

    theta = theta * 2.0*deflection*np.pi  # Rotation about the pole (Z).
    phi = phi * 2.0*np.pi  # For direction of pole deflection.
    z = z * 2.0*deflection  # For magnitude of pole deflection.

    # Compute a vector V used for distributing points over the sphere
    # via the reflection I - V Transpose(V).  This formulation of V
    # will guarantee that if x[1] and x[2] are uniformly distributed,
    # the reflected points will be uniform on the sphere.  Note that V
    # has length sqrt(2) to eliminate the 2 in the Householder matrix.

    r = np.sqrt(z)
    Vx, Vy, Vz = V = (
        np.sin(phi) * r,
        np.cos(phi) * r,
        np.sqrt(2.0 - z)
        )

    st = np.sin(theta)
    ct = np.cos(theta)

    R = np.array(((ct, st, 0), (-st, ct, 0), (0, 0, 1)))

    # Construct the rotation matrix  ( V Transpose(V) - I ) R.

    M = (np.outer(V, V) - np.eye(3)).dot(R)
    return M

rotation1 = rand_rotation_matrix()
rotation2 = rand_rotation_matrix()

print(Quaternion(rotation1.dot(rotation2.T)))

Answer 1

根据文档中的 Object Initialisation 部分（向下滚动方式），要从旋转矩阵进行初始化，您必须使用 matrix= 关键字参数，例如Quaternion(matrix=R).

pyquaternion: ValueError: Unexpected number of elements in sequence

pyquaternion: ValueError: Unexpected number of elements in sequence

python

numpy

rotation

quaternions

valueerror