// project on 1-dim histogram
TH1D *ProjectOn(char *nam, Int_t dim, const Int_t * const first=0, const Int_t * const last=0) const;
// project on 1-dim histogram
// project on 1-dim histogram
TH1D *ProjectOn(char *nam, Int_t dim, const Int_t * const first=0, const Int_t * const last=0) const;
// project on 1-dim histogram