T49DedxFunction

class T49DedxFunction : public TF1

    private:

                      T49DedxFunction()
                Int_t Binom(Int_t n, Int_t k)
                 void PolyFit(const Int_t NPoints, Float_t* x, Float_t* y, Float_t* err, Int_t Order, Float_t* Result)

    public:

                      T49DedxFunction(Char_t* name)
                      ~T49DedxFunction()
       static TClass* Class()
              Float_t GetAmplitude(Int_t i)
                 void GetBBPars(Float_t& c, Float_t& d, Float_t& e, Float_t& f)
              Float_t GetPosition(Int_t i)
              Float_t GetPtot()
                 void GetRatio(Int_t part, Float_t& val, Float_t& err)
                 void GetRatio2(Int_t part, Float_t& val, Float_t& err)
              Float_t GetRelPosition(Int_t i)
              Float_t GetRelRise(Int_t part)
              Float_t GetResolution()
                 void Init(TH1F* Hist, Char_t* Opt = "")
                 void InitPositions(Float_t pipos)
      virtual TClass* IsA() const
               Bool_t IsAmplitudeFixed(Int_t i)
              Float_t RelRise(Float_t Ptot, Int_t Part)
                 void ResetFreePosition(Int_t i)
                 void RestoreParameters()
                 void SetAmplitude(Int_t i, Float_t x, Float_t lowlim, Float_t uplim)
                 void SetAmplitude(Int_t i, Float_t x)
                 void SetBBPars(Float_t c, Float_t d, Float_t e, Float_t f)
                 void SetFixedAmplitude(Int_t i, Float_t x)
                 void SetFixedAmplitude(Int_t i)
                 void SetFixedPosition(Int_t i, Float_t x)
                 void SetFixedPosition(Int_t i)
                 void SetFree()
                 void SetFreePosition(Int_t i, Float_t x)
                 void SetFreePosition(Int_t i)
                 void SetPosition(Int_t i, Float_t x, Float_t lowlim = 0, Float_t uplim = 0)
                 void SetPtot(Float_t p)
                 void SetResolution(Float_t x)
         virtual void ShowMembers(TMemberInspector& insp, char* parent)
                 void StoreCovMat()
                 void StoreParameters()
         virtual void Streamer(TBuffer& b)
                 void StreamerNVirtual(TBuffer& b)

Data Members

    protected:

       Float_t fParaC            Constants for rel rise parametrisation
       Float_t fParaD            
       Float_t fParaE            
       Float_t fParaF            
       Float_t fPtot             
        Bool_t fAmpFix[4]        
      Double_t fStoredPars[9]    
      Double_t fStoredLowLim[9]  
      Double_t fStoredUpLim[9]   
        Bool_t fStored           

    public:

      Double_t fCovMatMinuit[9][9]  
       Float_t fCovMat[9][9]        

Class Description

  dE/dx fit function class

  This is an interface to a TF1, used to fit a dE/dx spectra.
  The function consists of four gaussians, with identical relative
  widths. Different methods are provide to fix or release the
  positions of the different peaks. Internally, the pion peak position
  is absolute, whereas the other peak positions are relative
  to it.

  Release bounds on relative positions (N.B. the pion position
  is not affected)

  Release bound on peak position i, and set position to x.

  Set fixed value for peak position i

  Release bounds on position of peak i

  Fix position of peak i

  Set position to Bethe Bloch value, and

  Set position and bounds. (N.B.: the bounds of non-pion peaks
  change with the pion peak position, since they are relative positions)

  Sets pion position to pipos, and relative positions of other peaks
  acoording to Bethe-Bloch parametrization

  Facility to fix the amplitude. Mainly used to fix amplitudes at zero.

  The class may hold one alternative set of parameters. This method
  stores the parameters internally.

  Sets the parameters to the values stored using StoreParameters().

  Returns the value of dE/dx from the Bethe-Bloch-parametrization. First
  call SetPtot()

  This method uses the histogram to provide an estimate for the peak
  positions, amplitudes and widths. Relies heavily on the Bethe-Bloch
  parametrization, so first call SetPtot(). Option "V" triggers
  verbose behaviour.

  Returns expected dE/dx values, according to Bethe-Bloch parametrization
  (Called by GetRelRise())
  ** Code provided by Christof Roland **

  Fits polynomial of form par[0] + par[1]*x +par[2]*x^2, etc
  Uses the provided errors as weights.
  (Called internally by Init())

  Calculates binomial coefficient n over k.
  Called by PolyFit()

Inline Functions

                   void ~T49DedxFunction()
                TClass* Class()
                TClass* IsA() const
                   void ShowMembers(TMemberInspector& insp, char* parent)
                   void Streamer(TBuffer& b)
                   void StreamerNVirtual(TBuffer& b)
                   void SetBBPars(Float_t c, Float_t d, Float_t e, Float_t f)
                   void GetBBPars(Float_t& c, Float_t& d, Float_t& e, Float_t& f)
                   void SetPtot(Float_t p)
                 Bool_t IsAmplitudeFixed(Int_t i)
                Float_t GetPtot()
        T49DedxFunction T49DedxFunction()