def quat_mul()

in mujoco_worldgen/util/rotation.py [0:0]

• 18 lines of code
• 1 McCabe index (conditional complexity)

def quat_mul(quat0, quat1):
    assert quat0.shape == quat1.shape
    assert quat0.shape[-1] == 4

    w0 = quat0[..., 0]
    x0 = quat0[..., 1]
    y0 = quat0[..., 2]
    z0 = quat0[..., 3]

    w1 = quat1[..., 0]
    x1 = quat1[..., 1]
    y1 = quat1[..., 2]
    z1 = quat1[..., 3]

    w = w0 * w1 - x0 * x1 - y0 * y1 - z0 * z1
    x = w0 * x1 + x0 * w1 + y0 * z1 - z0 * y1
    y = w0 * y1 + y0 * w1 + z0 * x1 - x0 * z1
    z = w0 * z1 + z0 * w1 + x0 * y1 - y0 * x1
    quat = np.stack([w, x, y, z], axis=-1)

    assert quat.shape == quat0.shape
    return quat