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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 *****************************************************************************/
19#include "RooResolutionModel.h"
20#include "RooRealProxy.h"
21#include "RooMath.h"
23#include <cmath>
24#include <complex>
38 enum BasisSign { Both=0, Plus=+1, Minus=-1 } ;
40 // Constructors, assignment etc
42 RooGaussModel(const char *name, const char *title, RooRealVar& x,
44 RooGaussModel(const char *name, const char *title, RooRealVar& x,
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();
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 ;
56 Int_t getGenerator(const RooArgSet& directVars, RooArgSet &generateVars, Bool_t staticInitOK=kTRUE) const;
57 void generateEvent(Int_t code);
61 void advertiseAymptoticIntegral(Bool_t flag) { _asympInt = flag ; } // added FMV,07/24/03
65 virtual Double_t evaluate() const ;
66 static std::complex<Double_t> evalCerfApprox(Double_t swt, Double_t u, Double_t c);
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 }
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;
80 Bool_t _asympInt ; // added FMV,07/24/03
87 ClassDef(RooGaussModel,1) // Gaussian Resolution Model
#define c(i)
Definition: RSha256.hxx:101
int Int_t
Definition: RtypesCore.h:41
const Bool_t kFALSE
Definition: RtypesCore.h:88
bool Bool_t
Definition: RtypesCore.h:59
double Double_t
Definition: RtypesCore.h:55
const Bool_t kTRUE
Definition: RtypesCore.h:87
#define ClassDef(name, id)
Definition: Rtypes.h:326
char name[80]
Definition: TGX11.cxx:109
double exp(double)
RooAbsReal is the common abstract base class for objects that represent a real value and implements f...
Definition: RooAbsReal.h:59
RooArgSet is a container object that can hold multiple RooAbsArg objects.
Definition: RooArgSet.h:28
Class RooGaussModel implements a RooResolutionModel that models a Gaussian distribution.
Definition: RooGaussModel.h:26
RooRealProxy sigma
Definition: RooGaussModel.h:83
Bool_t _asympInt
Definition: RooGaussModel.h:80
Bool_t _flatSFInt
Definition: RooGaussModel.h:78
RooRealProxy msf
Definition: RooGaussModel.h:84
virtual ~RooGaussModel()
std::complex< Double_t > evalCerfInt(Double_t sign, Double_t wt, Double_t tau, Double_t umin, Double_t umax, Double_t c) const
static std::complex< Double_t > evalCerf(Double_t swt, Double_t u, Double_t c)
Definition: RooGaussModel.h:69
static std::complex< Double_t > evalCerfApprox(Double_t swt, Double_t u, Double_t c)
use the approximation: erf(z) = exp(-z*z)/(std::sqrt(pi)*z) to explicitly cancel the divergent exp(y*...
void advertiseFlatScaleFactorIntegral(Bool_t flag)
Definition: RooGaussModel.h:59
virtual Double_t analyticalIntegral(Int_t code, const char *rangeName) const
Implements the actual analytical integral(s) advertised by getAnalyticalIntegral.
Int_t getGenerator(const RooArgSet &directVars, RooArgSet &generateVars, Bool_t staticInitOK=kTRUE) const
Load generatedVars with the subset of directVars that we can generate events for, and return a code t...
virtual Double_t evaluate() const
Evaluate this PDF / function / constant. Needs to be overridden by all derived classes.
void generateEvent(Int_t code)
Interface for generation of an event using the algorithm corresponding to the specified code.
virtual Int_t basisCode(const char *name) const
void advertiseAymptoticIntegral(Bool_t flag)
Definition: RooGaussModel.h:61
virtual Int_t getAnalyticalIntegral(RooArgSet &allVars, RooArgSet &analVars, const char *rangeName=0) const
Interface function getAnalyticalIntergral advertises the analytical integrals that are supported.
RooRealProxy mean
Definition: RooGaussModel.h:82
virtual TObject * clone(const char *newname) const
Definition: RooGaussModel.h:49
RooRealProxy ssf
Definition: RooGaussModel.h:85
static std::complex< double > faddeeva_fast(std::complex< double > z)
evaluate Faddeeva function for complex argument (fast version)
Definition: RooMath.cxx:549
RooRealVar represents a variable that can be changed from the outside.
Definition: RooRealVar.h:35
RooResolutionModel is the base class for PDFs that represent a resolution model that can be convolute...
Mother of all ROOT objects.
Definition: TObject.h:37