1. GAUDI Framework

2. Conventions QuantityUnit Lengthmillimetre Timenanosecond EnergyMeV Electic chargePositron charge TemperatureKelvin Amout of substancemole Plane angleradian Units: CLHEP system of units, used also in Geant4 http://wwwinfo.cern.ch/asd/lhc++/clhep/manual/UserGuide/Units/units.html It is an attempt to provide a practical System of Units for HEP applications.

3. All dimensioned quantities in the Gaudi data stores shall conform to the CLHEP system of units. All definitions of dimensioned quantities shall be dimensioned by multiplying by the units defined in the CLHEP/Units/SystemOfUnits.h header file. const double my_height = 170*cm; const double my_weight = 75*kg; All output of dimensioned quantities should be converted to the required units by dividing by the defined units. my_hist = histoSvc()->book( "/stat/diet","corpulence (kg/m**2)",30,10.,40.); double my_corpulence = my_weight / (my_height*my_height); my_hist->fill( my_corpulence/(kg/m2), 1. ); Physical constants should not be defined in user code. They should be taken directly from the CLHEP/Units/PhysicalConstants.h header file. float my_rest_energy = my_weight * c_squared;