def compute_nutation(t):
    """Generate the nutation rotations for Time `t`.

    If the Julian date is scalar, a simple ``(3, 3)`` matrix is
    returned; if the date is an array of length ``n``, then an array of
    matrices is returned with dimensions ``(3, 3, n)``.

    """
    oblm, oblt, eqeq, psi, eps = t._earth_tilt

    cobm = cos(oblm * DEG2RAD)
    sobm = sin(oblm * DEG2RAD)
    cobt = cos(oblt * DEG2RAD)
    sobt = sin(oblt * DEG2RAD)
    cpsi = cos(psi * ASEC2RAD)
    spsi = sin(psi * ASEC2RAD)

    return array(((cpsi,
                  -spsi * cobm,
                  -spsi * sobm),
                  (spsi * cobt,
                   cpsi * cobm * cobt + sobm * sobt,
                   cpsi * sobm * cobt - cobm * sobt),
                  (spsi * sobt,
                   cpsi * cobm * sobt - sobm * cobt,
                   cpsi * sobm * sobt + cobm * cobt)))
Generate the nutation rotations for Time `t`.

    If the Julian date is scalar, a simple ``(3, 3)`` matrix is
    returned; if the date is an array of length ``n``, then an array of
    matrices is returned with dimensions ``(3, 3, n)``.