I replaced the particle Gun with GPS, so I changed primarygeneratoraction. cc and .hh files, and “G4systemOfUnits.hh” is also included in the header.
But in .mac file, I get this error that says the unit is not defined. Based on the GPS manual, The units can be micron, mm, cm, m or km, and I used micron, mm and cm, and none worked.
Any help in this matter would be greatly appreciated.