def euler_to_quaternion()

in common/quaternion.py [0:0]

• 28 lines of code
• 7 McCabe index (conditional complexity)

def euler_to_quaternion(e, order):
    """
    Convert Euler angles to quaternions.
    """
    assert e.shape[-1] == 3
    
    original_shape = list(e.shape)
    original_shape[-1] = 4
    
    e = e.reshape(-1, 3)
    
    x = e[:, 0]
    y = e[:, 1]
    z = e[:, 2]
    
    rx = np.stack((np.cos(x/2), np.sin(x/2), np.zeros_like(x), np.zeros_like(x)), axis=1)
    ry = np.stack((np.cos(y/2), np.zeros_like(y), np.sin(y/2), np.zeros_like(y)), axis=1)
    rz = np.stack((np.cos(z/2), np.zeros_like(z), np.zeros_like(z), np.sin(z/2)), axis=1)

    result = None
    for coord in order:
        if coord == 'x':
            r = rx
        elif coord == 'y':
            r = ry
        elif coord == 'z':
            r = rz
        else:
            raise
        if result is None:
            result = r
        else:
            result = qmul_np(result, r)
            
    # Reverse antipodal representation to have a non-negative "w"
    if order in ['xyz', 'yzx', 'zxy']:
        result *= -1
    
    return result.reshape(original_shape)