[u/mrichter/AliRoot.git] / ITS / AliITSPidParItem.cxx

/////////////////////////////////////////////////////////
//Class for PID in the ITS                             //
//                                                     //
//                                                     //
/////////////////////////////////////////////////////////

#include <Riostream.h>
#include <TF1.h>
#include "AliITSPidParItem.h"

ClassImp(AliITSPidParItem)
//____________________________________________________________________
AliITSPidParItem::AliITSPidParItem(){
  // default constructor
  fPCenter=0;
  fPWidth=0;
  for(Int_t i=0;i<39;i++){
  fBuff[i]=0;
  }
}//____________________________________________________________________
AliITSPidParItem::AliITSPidParItem(Float_t center,Float_t width,Double_t *buff){
  // standard constructor
  fPCenter=center;
  fPWidth=width;
  for (Int_t i=0;i<39;i++) fBuff[i]=buff[i];

}

//____________________________________________________________________
void AliITSPidParItem::GetParameters(Double_t *buff) const{
  //get all the parameters
  for (Int_t i=0;i<39;i++) buff[i]=fBuff[i];

}
//____________________________________________________________________
void AliITSPidParItem::GetProtonPar(Double_t *buffp) const{
  //get the protons' parameters (Width Landau, Most Probable, Area, Width Gaussian, Chi2 fit, NDF fit, Integral fit)
  buffp[0]=fBuff[0];
  buffp[1]=fBuff[1];
  buffp[2]=fBuff[2];
  buffp[3]=fBuff[3];
  buffp[4]=fBuff[8];
  buffp[5]=fBuff[9];
  buffp[6]=fBuff[10];
}
//____________________________________________________________________
void AliITSPidParItem::GetKaonPar(Double_t *buffk) const{
  //get the kaons' parameters (Width Landau, Most Probable, Area, Width Gaussian, Chi2 fit, NDF fit, Integral fit)
  buffk[0]=fBuff[13];
  buffk[1]=fBuff[14];
  buffk[2]=fBuff[15];
  buffk[3]=fBuff[16];
  buffk[4]=fBuff[21];
  buffk[5]=fBuff[22];
  buffk[6]=fBuff[23];
}
//____________________________________________________________________
void AliITSPidParItem::GetPionPar(Double_t *buffpi) const{
  //get the pions' parameters (Width Landau, Most Probable, Area, Width Gaussian, Chi2 fit, NDF fit, Integral fit)
  buffpi[0]=fBuff[26];
  buffpi[1]=fBuff[27];
  buffpi[2]=fBuff[28];
  buffpi[3]=fBuff[29];
  buffpi[4]=fBuff[34];
  buffpi[5]=fBuff[35];
  buffpi[6]=fBuff[36];
}
//____________________________________________________________________
void AliITSPidParItem::GetPar0(Double_t *buff0) const{
  //Width Landau for protons, kaons, pions.
  buff0[0]=fBuff[0];
  buff0[1]=fBuff[13];
  buff0[2]=fBuff[26];
}
//____________________________________________________________________
void AliITSPidParItem::GetPar1(Double_t *buff1) const{
  //Most Probable for protons, kaons, pions.
  buff1[0]=fBuff[1];
  buff1[1]=fBuff[14];
  buff1[2]=fBuff[27];
}
//____________________________________________________________________
void AliITSPidParItem::GetPar2(Double_t *buff2) const{
  //Area for protons, kaons, pions.
  buff2[0]=fBuff[2];
  buff2[1]=fBuff[15];
  buff2[2]=fBuff[28];
}
//____________________________________________________________________
void AliITSPidParItem::GetPar3(Double_t *buff3) const{
  //Width Gaussian for protons, kaons, pions.
  buff3[0]=fBuff[3];
  buff3[1]=fBuff[16];
  buff3[2]=fBuff[29];
}
//____________________________________________________________________
void AliITSPidParItem::GetChisquare(Double_t *buffchi) const{
  //Chi2 of the fit for protons, kaons, pions.
  buffchi[0]=fBuff[8];
  buffchi[1]=fBuff[21];
  buffchi[2]=fBuff[34];
}
//____________________________________________________________________
void AliITSPidParItem::GetNDF(Double_t *buffndf) const{
  //NDF of the fit for protons, kaons, pions.
  buffndf[0]=fBuff[9];
  buffndf[1]=fBuff[22];
  buffndf[2]=fBuff[35];
}
//____________________________________________________________________
void AliITSPidParItem::GetProParFun(Double_t *pfun) const{
  //some Protons parameters: Width Landau, Most Probable, Area, Width Gaussian, Integral fit
  pfun[0]=fBuff[0];
  pfun[1]=fBuff[1];
  pfun[2]=fBuff[2];
  pfun[3]=fBuff[3];
  pfun[4]=fBuff[10];
}
//____________________________________________________________________
void AliITSPidParItem::GetKaoParFun(Double_t *kfun) const{
  //some Kaons parameters: Width Landau, Most Probable, Area, Width Gaussian, Integral fit
  kfun[0]=fBuff[13];
  kfun[1]=fBuff[14];
  kfun[2]=fBuff[15];
  kfun[3]=fBuff[16];
  kfun[4]=fBuff[23];
}
//____________________________________________________________________
void AliITSPidParItem::GetPiParFun(Double_t *pifun) const{
  //some Pions parameters: Width Landau, Most Probable, Area, Width Gaussian, Integral fit
  pifun[0]=fBuff[26];
  pifun[1]=fBuff[27];
  pifun[2]=fBuff[28];
  pifun[3]=fBuff[29];
  pifun[4]=fBuff[36];
}
//____________________________________________________________________
void AliITSPidParItem::GetRangeLim(Double_t *range) const{
  //Range limits for the response functions
  range[0]=fBuff[11];//proton low
  range[1]=fBuff[12];//proton high
  range[2]=fBuff[24];//kaon low
  range[3]=fBuff[25];//kaon high
  range[4]=fBuff[37];//pion low
  range[5]=fBuff[38];//pion high
}
//____________________________________________________________________
void AliITSPidParItem::GetProtonParErr(Double_t *bufferp)const{
  //errors on the protons' parameters
  bufferp[0]=fBuff[4];
  bufferp[1]=fBuff[5];
  bufferp[2]=fBuff[6];
  bufferp[3]=fBuff[7];
}
//____________________________________________________________________
void AliITSPidParItem::GetKaonParErr(Double_t *bufferk)const{
  //errors on the kaons' parameters
  bufferk[0]=fBuff[17];
  bufferk[1]=fBuff[18];
  bufferk[2]=fBuff[19];
  bufferk[3]=fBuff[20];
}
//____________________________________________________________________
void AliITSPidParItem::GetPionParErr(Double_t *bufferpi)const{
  //errors on the pions' parameters
  bufferpi[0]=fBuff[30];
  bufferpi[1]=fBuff[31];
  bufferpi[2]=fBuff[32];
  bufferpi[3]=fBuff[33];
}
//____________________________________________________________________
void AliITSPidParItem::PrintParameters() const {
  // Prints the data members of this class
cout<<"==============================***************"<<endl;
cout<<"Momentum (GeV/c) - center of the bin - "<<fPCenter<<endl;
cout<<" Width of momentum bin (GeV/c) "<<fPWidth<<endl;
for (Int_t i=0;i<39;i++) cout<<"Parameter"<<i<<" = "<<fBuff[i]<<endl;

}

//_______________________________________________________________________
TF1* AliITSPidParItem::CookFunIts(TString namefun,Double_t *par,Double_t rangei,Double_t rangef,TString comment){
  //
  TF1 *fun;
    if (par[4]!=0) {
      fun=new TF1(comment,Langaufun2,rangei,rangef,5);
      fun->SetParameters(par);
     
    }
    else {fun=new TF1(namefun,"0");}
    return fun;
}

//_________________________________________________________________________
Double_t AliITSPidParItem::Langaufun(Double_t *x, Double_t *par) {

  //Fit parameters:
  //par[0]=Width (scale) parameter of Landau density
  //par[1]=Most Probable (MP, location) parameter of Landau density
  //par[2]=Total area (integral -inf to inf, normalization constant)
  //par[3]=Width (sigma) of convoluted Gaussian function
  //
  //In the Landau distribution (represented by the CERNLIB approximation), 
  //the maximum is located at x=-0.22278298 with the location parameter=0.
  //This shift is corrected within this function, so that the actual
  //maximum is identical to the MP parameter.

  // Numeric constants
  Double_t invsq2pi = 0.3989422804014;   // (2 pi)^(-1/2)
  Double_t mpshift  = -0.22278298;       // Landau maximum location

  // Control constants
  Double_t np = 100.0;      // number of convolution steps
  Double_t sc =   5.0;      // convolution extends to +-sc Gaussian sigmas

  // Variables
  Double_t xx;
  Double_t mpc;
  Double_t fland;
  Double_t sum = 0.0;
  Double_t xlow,xupp;
  Double_t step;
  Double_t i;


  // MP shift correction
  mpc = par[1] - mpshift * par[0]; 

  // Range of convolution integral
  xlow = x[0] - sc * par[3];
  xupp = x[0] + sc * par[3];

  step = (xupp-xlow) / np;

  // Convolution integral of Landau and Gaussian by sum
  for(i=1.0; i<=np/2; i++) {
    xx = xlow + (i-.5) * step;
    fland = TMath::Landau(xx,mpc,par[0]) / par[0];
    sum += fland * TMath::Gaus(x[0],xx,par[3]);

    xx = xupp - (i-.5) * step;
    fland = TMath::Landau(xx,mpc,par[0]) / par[0];
    sum += fland * TMath::Gaus(x[0],xx,par[3]);
  }

  return (par[2] * step * sum * invsq2pi / par[3]);
}
//_______________________________________________________________________
Double_t AliITSPidParItem::Langaufun2(Double_t *x, Double_t *par){
  //
  return 1/par[4]*Langaufun(x,par);
}
Commit	Line	Data
e62c1aea	1	/////////////////////////////////////////////////////////
	2	//Class for PID in the ITS //
	3	// //
	4	// //
	5	/////////////////////////////////////////////////////////
	6
	7	#include <Riostream.h>
	8	#include <TF1.h>
	9	#include "AliITSPidParItem.h"
	10
	11	ClassImp(AliITSPidParItem)
	12	//____________________________________________________________________
	13	AliITSPidParItem::AliITSPidParItem(){
	14	// default constructor
	15	fPCenter=0;
	16	fPWidth=0;
	17	for(Int_t i=0;i<39;i++){
	18	fBuff[i]=0;
	19	}
	20	}//____________________________________________________________________
	21	AliITSPidParItem::AliITSPidParItem(Float_t center,Float_t width,Double_t *buff){
	22	// standard constructor
	23	fPCenter=center;
	24	fPWidth=width;
	25	for (Int_t i=0;i<39;i++) fBuff[i]=buff[i];
	26
	27	}
	28
	29	//____________________________________________________________________
	30	void AliITSPidParItem::GetParameters(Double_t *buff) const{
	31	//get all the parameters
	32	for (Int_t i=0;i<39;i++) buff[i]=fBuff[i];
	33
	34	}
	35	//____________________________________________________________________
	36	void AliITSPidParItem::GetProtonPar(Double_t *buffp) const{
	37	//get the protons' parameters (Width Landau, Most Probable, Area, Width Gaussian, Chi2 fit, NDF fit, Integral fit)
	38	buffp[0]=fBuff[0];
	39	buffp[1]=fBuff[1];
	40	buffp[2]=fBuff[2];
	41	buffp[3]=fBuff[3];
	42	buffp[4]=fBuff[8];
	43	buffp[5]=fBuff[9];
	44	buffp[6]=fBuff[10];
	45	}
	46	//____________________________________________________________________
	47	void AliITSPidParItem::GetKaonPar(Double_t *buffk) const{
	48	//get the kaons' parameters (Width Landau, Most Probable, Area, Width Gaussian, Chi2 fit, NDF fit, Integral fit)
	49	buffk[0]=fBuff[13];
	50	buffk[1]=fBuff[14];
	51	buffk[2]=fBuff[15];
	52	buffk[3]=fBuff[16];
	53	buffk[4]=fBuff[21];
	54	buffk[5]=fBuff[22];
	55	buffk[6]=fBuff[23];
	56	}
	57	//____________________________________________________________________
	58	void AliITSPidParItem::GetPionPar(Double_t *buffpi) const{
	59	//get the pions' parameters (Width Landau, Most Probable, Area, Width Gaussian, Chi2 fit, NDF fit, Integral fit)
	60	buffpi[0]=fBuff[26];
	61	buffpi[1]=fBuff[27];
	62	buffpi[2]=fBuff[28];
	63	buffpi[3]=fBuff[29];
	64	buffpi[4]=fBuff[34];
65	buffpi[5]=fBuff[35];
66	buffpi[6]=fBuff[36];
67	}
68	//____________________________________________________________________
69	void AliITSPidParItem::GetPar0(Double_t *buff0) const{
70	//Width Landau for protons, kaons, pions.
71	buff0[0]=fBuff[0];
72	buff0[1]=fBuff[13];
73	buff0[2]=fBuff[26];
74	}
75	//____________________________________________________________________
76	void AliITSPidParItem::GetPar1(Double_t *buff1) const{
77	//Most Probable for protons, kaons, pions.
78	buff1[0]=fBuff[1];
79	buff1[1]=fBuff[14];
80	buff1[2]=fBuff[27];
81	}
82	//____________________________________________________________________
83	void AliITSPidParItem::GetPar2(Double_t *buff2) const{
84	//Area for protons, kaons, pions.
85	buff2[0]=fBuff[2];
86	buff2[1]=fBuff[15];
87	buff2[2]=fBuff[28];
88	}
89	//____________________________________________________________________
90	void AliITSPidParItem::GetPar3(Double_t *buff3) const{
91	//Width Gaussian for protons, kaons, pions.
92	buff3[0]=fBuff[3];
93	buff3[1]=fBuff[16];
94	buff3[2]=fBuff[29];
95	}
96	//____________________________________________________________________
97	void AliITSPidParItem::GetChisquare(Double_t *buffchi) const{
98	//Chi2 of the fit for protons, kaons, pions.
99	buffchi[0]=fBuff[8];
100	buffchi[1]=fBuff[21];
101	buffchi[2]=fBuff[34];
102	}
103	//____________________________________________________________________
104	void AliITSPidParItem::GetNDF(Double_t *buffndf) const{
105	//NDF of the fit for protons, kaons, pions.
106	buffndf[0]=fBuff[9];
107	buffndf[1]=fBuff[22];
108	buffndf[2]=fBuff[35];
109	}
110	//____________________________________________________________________
111	void AliITSPidParItem::GetProParFun(Double_t *pfun) const{
112	//some Protons parameters: Width Landau, Most Probable, Area, Width Gaussian, Integral fit
113	pfun[0]=fBuff[0];
114	pfun[1]=fBuff[1];
115	pfun[2]=fBuff[2];
116	pfun[3]=fBuff[3];
117	pfun[4]=fBuff[10];
118	}
119	//____________________________________________________________________
120	void AliITSPidParItem::GetKaoParFun(Double_t *kfun) const{
121	//some Kaons parameters: Width Landau, Most Probable, Area, Width Gaussian, Integral fit
122	kfun[0]=fBuff[13];
123	kfun[1]=fBuff[14];
124	kfun[2]=fBuff[15];
125	kfun[3]=fBuff[16];
126	kfun[4]=fBuff[23];
127	}
128	//____________________________________________________________________
129	void AliITSPidParItem::GetPiParFun(Double_t *pifun) const{
130	//some Pions parameters: Width Landau, Most Probable, Area, Width Gaussian, Integral fit
131	pifun[0]=fBuff[26];
132	pifun[1]=fBuff[27];
133	pifun[2]=fBuff[28];
134	pifun[3]=fBuff[29];
135	pifun[4]=fBuff[36];
136	}
137	//____________________________________________________________________
138	void AliITSPidParItem::GetRangeLim(Double_t *range) const{
139	//Range limits for the response functions
140	range[0]=fBuff[11];//proton low
141	range[1]=fBuff[12];//proton high
142	range[2]=fBuff[24];//kaon low
143	range[3]=fBuff[25];//kaon high
144	range[4]=fBuff[37];//pion low
145	range[5]=fBuff[38];//pion high
146	}
147	//____________________________________________________________________
148	void AliITSPidParItem::GetProtonParErr(Double_t *bufferp)const{
149	//errors on the protons' parameters
150	bufferp[0]=fBuff[4];
151	bufferp[1]=fBuff[5];
152	bufferp[2]=fBuff[6];
153	bufferp[3]=fBuff[7];
154	}
155	//____________________________________________________________________
156	void AliITSPidParItem::GetKaonParErr(Double_t *bufferk)const{
157	//errors on the kaons' parameters
158	bufferk[0]=fBuff[17];
159	bufferk[1]=fBuff[18];
160	bufferk[2]=fBuff[19];
161	bufferk[3]=fBuff[20];
162	}
163	//____________________________________________________________________
164	void AliITSPidParItem::GetPionParErr(Double_t *bufferpi)const{
165	//errors on the pions' parameters
166	bufferpi[0]=fBuff[30];
167	bufferpi[1]=fBuff[31];
168	bufferpi[2]=fBuff[32];
169	bufferpi[3]=fBuff[33];
170	}
171	//____________________________________________________________________
172	void AliITSPidParItem::PrintParameters() const {
173	// Prints the data members of this class
174	cout<<"==============================***************"<<endl;
175	cout<<"Momentum (GeV/c) - center of the bin - "<<fPCenter<<endl;
176	cout<<" Width of momentum bin (GeV/c) "<<fPWidth<<endl;
177	for (Int_t i=0;i<39;i++) cout<<"Parameter"<<i<<" = "<<fBuff[i]<<endl;
178
179	}
180
181	//_______________________________________________________________________
182	TF1* AliITSPidParItem::CookFunIts(TString namefun,Double_t *par,Double_t rangei,Double_t rangef,TString comment){
183	//
184	TF1 *fun;
185	if (par[4]!=0) {
186	fun=new TF1(comment,Langaufun2,rangei,rangef,5);
187	fun->SetParameters(par);
188
189	}
190	else {fun=new TF1(namefun,"0");}
191	return fun;
192	}
193
194	//_________________________________________________________________________
195	Double_t AliITSPidParItem::Langaufun(Double_t x, Double_t par) {
196
197	//Fit parameters:
198	//par[0]=Width (scale) parameter of Landau density
199	//par[1]=Most Probable (MP, location) parameter of Landau density
200	//par[2]=Total area (integral -inf to inf, normalization constant)
201	//par[3]=Width (sigma) of convoluted Gaussian function
202	//
203	//In the Landau distribution (represented by the CERNLIB approximation),
204	//the maximum is located at x=-0.22278298 with the location parameter=0.
205	//This shift is corrected within this function, so that the actual
206	//maximum is identical to the MP parameter.
207
208	// Numeric constants
209	Double_t invsq2pi = 0.3989422804014; // (2 pi)^(-1/2)
210	Double_t mpshift = -0.22278298; // Landau maximum location
211
212	// Control constants
213	Double_t np = 100.0; // number of convolution steps
214	Double_t sc = 5.0; // convolution extends to +-sc Gaussian sigmas
215
216	// Variables
217	Double_t xx;
218	Double_t mpc;
219	Double_t fland;
220	Double_t sum = 0.0;
221	Double_t xlow,xupp;
222	Double_t step;
223	Double_t i;
224
225
226	// MP shift correction
227	mpc = par[1] - mpshift * par[0];
228
229	// Range of convolution integral
230	xlow = x[0] - sc * par[3];
231	xupp = x[0] + sc * par[3];
232
233	step = (xupp-xlow) / np;
234
235	// Convolution integral of Landau and Gaussian by sum
236	for(i=1.0; i<=np/2; i++) {
237	xx = xlow + (i-.5) * step;
238	fland = TMath::Landau(xx,mpc,par[0]) / par[0];
239	sum += fland * TMath::Gaus(x[0],xx,par[3]);
240
241	xx = xupp - (i-.5) * step;
242	fland = TMath::Landau(xx,mpc,par[0]) / par[0];
243	sum += fland * TMath::Gaus(x[0],xx,par[3]);
244	}
245
246	return (par[2] * step * sum * invsq2pi / par[3]);
247	}
248	//_______________________________________________________________________
249	Double_t AliITSPidParItem::Langaufun2(Double_t x, Double_t par){
250	//
251	return 1/par[4]*Langaufun(x,par);
252	}