<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def update(self):
 """Delete the coefficients of the pure MA model and also all MA and AR coefficients of the ARMA model. Also calculate or delete the values of all secondary iuh parameters, depending on the completeness of the values of the primary parameters. """

        del self.ma.coefs
        del self.arma.ma_coefs
        del self.arma.ar_coefs
        if self.primary_parameters_complete:
            self.calc_secondary_parameters()
        else:
            for secpar in self._SECONDARY_PARAMETERS.values():
                secpar.__delete__(self)