<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):
 """Determine all MA coefficients. ma_coefs([[1.0, nan, nan], [1.0, 2.0, 3.0]]) Note that updating parameter `ar_coefs` sets the shape of the log sequence |LogIn| automatically. login([[nan, nan, nan], [nan, nan, nan]]) """

        pars = self.subpars.pars
        coefs = pars.control.responses.ma_coefs
        self.shape = coefs.shape
        self(coefs)
        pars.model.sequences.logs.login.shape = self.shape