Double_t VdriftLinearHyperplaneApprox(Double_t dE, Double_t dT, Double_t dP, Double_t dCco2, Double_t dCn2);
Double_t GetVdriftNominal();
Double_t VdriftLinearHyperplaneApprox(Double_t dE, Double_t dT, Double_t dP, Double_t dCco2, Double_t dCn2);
Double_t GetVdriftNominal();