def axisar(axis, angle):
    """
    Construct a rotation matrix that rotates vectors by a specified
    angle about a specified axis.

    http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/axisar_c.html

    :param axis: Rotation axis. 
    :type axis: 3 Element vector (list, tuple, numpy array)
    :param angle: Rotation angle, in radians. 
    :type angle: float
    :return: Rotation matrix corresponding to axis and angle.
    :rtype: numpy array ((3, 3))
    """
    axis = stypes.toDoubleVector(axis)
    angle = ctypes.c_double(angle)
    r = stypes.emptyDoubleMatrix()
    libspice.axisar_c(axis, angle, r)
    return stypes.cMatrixToNumpy(r)