Logo ROOT   6.30.04
Reference Guide
 All Namespaces Files Pages
RooGaussModel.h
Go to the documentation of this file.
1 /*****************************************************************************
2  * Project: RooFit *
3  * Package: RooFitModels *
4  * File: $Id: RooGaussModel.h,v 1.21 2007/05/11 09:13:07 verkerke Exp $
5  * Authors: *
6  * WV, Wouter Verkerke, UC Santa Barbara, verkerke@slac.stanford.edu *
7  * DK, David Kirkby, UC Irvine, dkirkby@uci.edu *
8  * *
9  * Copyright (c) 2000-2005, Regents of the University of California *
10  * and Stanford University. All rights reserved. *
11  * *
12  * Redistribution and use in source and binary forms, *
13  * with or without modification, are permitted according to the terms *
14  * listed in LICENSE (http://roofit.sourceforge.net/license.txt) *
15  *****************************************************************************/
16 #ifndef ROO_GAUSS_MODEL
17 #define ROO_GAUSS_MODEL
18 
19 #include "RooResolutionModel.h"
20 #include "RooRealProxy.h"
21 #include "RooMath.h"
22 
23 #include <cmath>
24 #include <complex>
25 
26 class RooGaussModel : public RooResolutionModel {
27 public:
28 
29  enum RooGaussBasis { noBasis=0, expBasisMinus= 1, expBasisSum= 2, expBasisPlus= 3,
30  sinBasisMinus=11, sinBasisSum=12, sinBasisPlus=13,
31  cosBasisMinus=21, cosBasisSum=22, cosBasisPlus=23,
32  linBasisPlus=33,
33  quadBasisPlus=43,
34  coshBasisMinus=51,coshBasisSum=52,coshBasisPlus=53,
35  sinhBasisMinus=61,sinhBasisSum=62,sinhBasisPlus=63};
36  enum BasisType { none=0, expBasis=1, sinBasis=2, cosBasis=3,
37  linBasis=4, quadBasis=5, coshBasis=6, sinhBasis=7 } ;
38  enum BasisSign { Both=0, Plus=+1, Minus=-1 } ;
39 
40  // Constructors, assignment etc
41  inline RooGaussModel() : _flatSFInt(kFALSE), _asympInt(kFALSE) { }
42  RooGaussModel(const char *name, const char *title, RooRealVar& x,
43  RooAbsReal& mean, RooAbsReal& sigma) ;
44  RooGaussModel(const char *name, const char *title, RooRealVar& x,
45  RooAbsReal& mean, RooAbsReal& sigma, RooAbsReal& msSF) ;
46  RooGaussModel(const char *name, const char *title, RooRealVar& x,
47  RooAbsReal& mean, RooAbsReal& sigma, RooAbsReal& meanSF, RooAbsReal& sigmaSF) ;
48  RooGaussModel(const RooGaussModel& other, const char* name=0);
49  virtual TObject* clone(const char* newname) const { return new RooGaussModel(*this,newname) ; }
50  virtual ~RooGaussModel();
51 
52  virtual Int_t basisCode(const char* name) const ;
53  virtual Int_t getAnalyticalIntegral(RooArgSet& allVars, RooArgSet& analVars, const char* rangeName=0) const ;
54  virtual Double_t analyticalIntegral(Int_t code, const char* rangeName) const ;
55 
56  Int_t getGenerator(const RooArgSet& directVars, RooArgSet &generateVars, Bool_t staticInitOK=kTRUE) const;
57  void generateEvent(Int_t code);
58 
59  void advertiseFlatScaleFactorIntegral(Bool_t flag) { _flatSFInt = flag ; }
60 
61  void advertiseAymptoticIntegral(Bool_t flag) { _asympInt = flag ; } // added FMV,07/24/03
62 
63 protected:
64 
65  virtual Double_t evaluate() const ;
66  static std::complex<Double_t> evalCerfApprox(Double_t swt, Double_t u, Double_t c);
67 
68  // Calculate exp(-u^2) cwerf(swt*c + i(u+c)), taking care of numerical instabilities
69  static inline std::complex<Double_t> evalCerf(Double_t swt, Double_t u, Double_t c)
70  {
71  std::complex<Double_t> z(swt*c,u+c);
72  return (z.imag()>-4.0) ? (std::exp(-u*u)*RooMath::faddeeva_fast(z)) : evalCerfApprox(swt,u,c);
73  }
74 
75  // Calculate common normalization factors
76  std::complex<Double_t> evalCerfInt(Double_t sign, Double_t wt, Double_t tau, Double_t umin, Double_t umax, Double_t c) const;
77 
78  Bool_t _flatSFInt ;
79 
80  Bool_t _asympInt ; // added FMV,07/24/03
81 
82  RooRealProxy mean ;
83  RooRealProxy sigma ;
84  RooRealProxy msf ;
85  RooRealProxy ssf ;
86 
87  ClassDef(RooGaussModel,1) // Gaussian Resolution Model
88 };
89 
90 #endif