def derived(self, name, relative_coords, formula):
relZ, relN = relative_coords<EOL>daughter_idx = [(x[<NUM_LIT:0>] + relZ, x[<NUM_LIT:1>] + relN) for x in self.df.index]<EOL>values = formula(self.df.values, self.df.loc[daughter_idx].values)<EOL>return Table(df=pd.Series(values, index=self.df.index, name=name + '<STR_LIT:(>' + self.name + '<STR_LIT:)>'))<EOL>
Helper function for derived quantities