def _update_dPrxy(self):
super(ExpCM_fitprefs, self)._update_dPrxy()<EOL>if '<STR_LIT>' in self.freeparams:<EOL><INDENT>self.dPrxy['<STR_LIT>'].fill(<NUM_LIT:0.0>)<EOL>tildeFrxyQxy = self.tildeFrxy * self.Qxy<EOL>j = <NUM_LIT:0><EOL>for r in range(self.nsites):<EOL><INDENT>for i in range(N_AA - <NUM_LIT:1>):<EOL><INDENT>zetari = self.zeta[j]<EOL>self.dPrxy['<STR_LIT>'][j][r] = tildeFrxyQxy[r] * (<EOL>((i == self._aa_for_y).astype('<STR_LIT:float>') -<EOL>(i == self._aa_for_x).astype('<STR_LIT:float>')) / zetari)<EOL>j += <NUM_LIT:1><EOL><DEDENT><DEDENT>for j in range(self.dPrxy['<STR_LIT>'].shape[<NUM_LIT:0>]):<EOL><INDENT>_fill_diagonals(self.dPrxy['<STR_LIT>'][j], self._diag_indices)<EOL><DEDENT><DEDENT>
Update `dPrxy`.