def get_best_fit_parameters_grouped(self):
        """Returns a dictionary of the best fit."""
        result_dict = dict()
        result_dict['ocv'] = [parameters['ocv'] for parameters in
                              self.best_fit_parameters]

        for i in range(self.circuits):
            result_dict['t' + str(i)] = [parameters['t' + str(i)] for parameters
                                         in self.best_fit_parameters]
            result_dict['w' + str(i)] = [parameters['w' + str(i)] for parameters
                                         in self.best_fit_parameters]
        return result_dict
Returns a dictionary of the best fit.