__init__.py 文件源码

def rotation_matrix(axis, angle):
    """
    Calculate a three dimensional rotation matrix for a rotation around
    the given angle and axis.

    @type axis: (3,) numpy array
    @param angle: angle in radians
    @type angle: float

    @rtype: (3,3) numpy.array
    """
    axis = numpy.asfarray(axis) / norm(axis)
    assert axis.shape == (3,)

    c = math.cos(angle)
    s = math.sin(angle)

    r = (1.0 - c) * numpy.outer(axis, axis)
    r.flat[[0,4,8]] += c
    r.flat[[5,6,1]] += s * axis
    r.flat[[7,2,3]] -= s * axis

    return r