(th)
return rv
Return the matrix to rotate a 2-D point about the origin by ``angle``.

    The angle is measured in radians. To Point a point about a point other
    then the origin, translate the Point, do the rotation, and
    translate it back:

    >>> from sympy.geometry.entity import rotate, translate
    >>> from sympy import Point, pi
    >>> rot_about_11 = translate(-1, -1)*rotate(pi/2)*translate(1, 1)
    >>> Point(1, 1).transform(rot_about_11)
    Point(1, 1)
    >>> Point(0, 0).transform(rot_about_11)
    Point(2, 0)
Return the matrix to rotate a 2-D point about the origin by ``angle``.
Return the matrix to rotate a 2 - D point about the origin by angle .
def rotate(th):
    """Return the matrix to rotate a 2-D point about the origin by ``angle``.

    The angle is measured in radians. To Point a point about a point other
    then the origin, translate the Point, do the rotation, and
    translate it back:

    >>> from sympy.geometry.entity import rotate, translate
    >>> from sympy import Point, pi
    >>> rot_about_11 = translate(-1, -1)*rotate(pi/2)*translate(1, 1)
    >>> Point(1, 1).transform(rot_about_11)
    Point(1, 1)
    >>> Point(0, 0).transform(rot_about_11)
    Point(2, 0)
    """
    s = sin(th)
    rv = eye(3)*cos(th)
    rv[0, 1] = s
    rv[1, 0] = -s
    rv[2, 2] = 1
    return rv
def rotate ( th ) : s = sin ( th ) rv = eye ( 3 ) * cos ( th ) rv [ 0 , 1 ] = s rv [ 1 , 0 ] = - s rv [ 2 , 2 ] = 1 return rv