  The rotating vector model and radius-to-frequency mapping in the presence of
multipole magnetic field in pulsars and magnetars are considered. An
axisymmetric potential field is assumed. It is found that: (1) The radiation
beam in the case of multipole field is wider than the dipole case. This may
account the increasing pulse width at higher frequency of pulsars
(anti-radius-to-frequency mapping). (2) The expression for the polarization
position angle is unchanged. Only the inclination angle {\alpha} and phase
constant {\phi}_0 will change. The angle between the rotational axis and line
of sight, and the position angle constant {\psi}_0 will not change. When
fitting the varying position angle of magnetars, these constraints should be
considered. The appearance and disappearance of multipole field may account for
the changing slope of position angle in the radio emitting magnetar Swift
J1818.0-1607. Similar but more active process in magnetar magnetospheres may
account for the diverse position angle in fast radius bursts.
