def start_pan(self, x, y, button):
    angle = np.deg2rad(self._r_label_position.to_values()[4])
    mode = ''
    if (button == 1):
        epsilon = (np.pi / 45.0)
        (t, r) = self.transData.inverted().transform_point((x, y))
        if ((t >= (angle - epsilon)) and (t <= (angle + epsilon))):
            mode = 'drag_r_labels'
    elif (button == 3):
        mode = 'zoom'
    self._pan_start = cbook.Bunch(rmax=self.get_rmax(), trans=self.transData.frozen(), trans_inverse=self.transData.inverted().frozen(), r_label_angle=self._r_label_position.to_values()[4], x=x, y=y, mode=mode)
def start_pan(self, x, y, button):
    angle = np.deg2rad(self._r_label_position.to_values()[4])
    mode = 
    if (button == 1):
        epsilon = (np.pi / 45.0)
        (t, r) = self.transData.inverted().transform_point((x, y))
        if ((t >= (angle - epsilon)) and (t <= (angle + epsilon))):
            mode = 'drag_r_labels'
    elif (button == 3):
        mode = 'zoom'
    self._pan_start = cbook.Bunch(rmax=self.get_rmax(), trans=self.transData.frozen(), trans_inverse=self.transData.inverted().frozen(), r_label_angle=self._r_label_position.to_values()[4], x=x, y=y, mode=mode)