New functions (Marian)

diff --git a/STEER/AliMathBase.cxx b/STEER/AliMathBase.cxx
index 36ee5b2b124fa48b020b7ed81d3afda1f31865ee..1c8c5ec30f341f3f760a11a6745153e7c2a10811 100644 (file)
--- a/STEER/AliMathBase.cxx
+++ b/STEER/AliMathBase.cxx
@@ -24,6 +24,9 @@
 #include "TMath.h"
 #include "AliMathBase.h"
 #include "Riostream.h"
+#include "TH1F.h"
+#include "TF1.h"
+#include "TLinearFitter.h"
  
 ClassImp(AliMathBase) // Class implementation to enable ROOT I/O
  
@@ -194,3 +197,162 @@ Int_t AliMathBase::Freq(Int_t n, const Int_t *inlist
   return countPos;
 
 }
+
+//___AliMathBase__________________________________________________________________________
+void AliMathBase::TruncatedMean(TH1F * his, TVectorD *param, Float_t down, Float_t up, Bool_t verbose){
+  //
+  //
+  //
+  Int_t nbins    = his->GetNbinsX();
+  Float_t nentries = his->GetEntries();
+  Float_t sum      =0;
+  Float_t mean   = 0;
+  Float_t sigma2 = 0;
+  Float_t ncumul=0;  
+  for (Int_t ibin=1;ibin<nbins; ibin++){
+    ncumul+= his->GetBinContent(ibin);
+    Float_t fraction = Float_t(ncumul)/Float_t(nentries);
+    if (fraction>down && fraction<up){
+      sum+=his->GetBinContent(ibin);
+      mean+=his->GetBinCenter(ibin)*his->GetBinContent(ibin);
+      sigma2+=his->GetBinCenter(ibin)*his->GetBinCenter(ibin)*his->GetBinContent(ibin);      
+    }
+  }
+  mean/=sum;
+  sigma2= TMath::Sqrt(TMath::Abs(sigma2/sum-mean*mean));
+  if (param){
+    (*param)[0] = his->GetMaximum();
+    (*param)[1] = mean;
+    (*param)[2] = sigma2;
+    
+  }
+  if (verbose)  printf("Mean\t%f\t Sigma2\t%f\n", mean,sigma2);
+}
+
+void AliMathBase::LTM(TH1F * his, TVectorD *param , Float_t fraction,  Bool_t verbose){
+  //
+  // LTM
+  //
+  Int_t nbins    = his->GetNbinsX();
+  Int_t nentries = (Int_t)his->GetEntries();
+  Double_t *data  = new Double_t[nentries];
+  Int_t npoints=0;
+  for (Int_t ibin=1;ibin<nbins; ibin++){
+    Float_t entriesI = his->GetBinContent(ibin);
+    Float_t xcenter= his->GetBinCenter(ibin);
+    for (Int_t ic=0; ic<entriesI; ic++){
+      if (npoints<nentries){
+       data[npoints]= xcenter;
+       npoints++;
+      }
+    }
+  }
+  Double_t mean, sigma;
+  Int_t npoints2=TMath::Min(Int_t(fraction*Float_t(npoints)),npoints-1);
+  npoints2=TMath::Max(Int_t(0.5*Float_t(npoints)),npoints2);
+  AliMathBase::EvaluateUni(npoints, data, mean,sigma,npoints2);
+  delete [] data;
+  if (verbose)  printf("Mean\t%f\t Sigma2\t%f\n", mean,sigma);if (param){
+    (*param)[0] = his->GetMaximum();
+    (*param)[1] = mean;
+    (*param)[2] = sigma;    
+  }
+}
+
+Double_t  AliMathBase::FitGaus(TH1F* his, TVectorD *param, TMatrixD *matrix, Float_t xmin, Float_t xmax, Bool_t verbose){
+  //
+  //  Fit histogram with gaussian function
+  //  
+  //  Prameters:
+  //       return value- chi2 - if negative ( not enough points)
+  //       his        -  input histogram
+  //       param      -  vector with parameters 
+  //       xmin, xmax -  range to fit - if xmin=xmax=0 - the full histogram range used
+  //  Fitting:
+  //  1. Step - make logarithm
+  //  2. Linear  fit (parabola) - more robust - always converge
+  //  3. In case of small statistic bins are averaged
+  //  
+  static TLinearFitter fitter(3,"pol2");
+  TVectorD  par(3);
+  TVectorD  sigma(3);
+  TMatrixD mat(3,3);
+  if (his->GetMaximum()<4) return -1;  
+  if (his->GetEntries()<12) return -1;  
+  if (his->GetRMS()<mat.GetTol()) return -1;
+  Float_t maxEstimate   = his->GetEntries()*his->GetBinWidth(1)/TMath::Sqrt((2.*TMath::Pi()*his->GetRMS()));  
+  Int_t dsmooth = TMath::Nint(6./TMath::Sqrt(maxEstimate));
+
+  if (maxEstimate<1) return -1;
+  Int_t nbins    = his->GetNbinsX();
+  Int_t npoints=0;
+  //
+
+
+  if (xmin>=xmax){
+    xmin = his->GetXaxis()->GetXmin();
+    xmax = his->GetXaxis()->GetXmax();
+  }
+  for (Int_t iter=0; iter<2; iter++){
+    fitter.ClearPoints();
+    npoints=0;
+    for (Int_t ibin=1;ibin<nbins-1; ibin++){      
+      Int_t countB=1;
+      Float_t entriesI =  his->GetBinContent(ibin);
+      for (Int_t delta = -dsmooth; delta<=dsmooth; delta++){
+       if (ibin+delta>1 &&ibin+delta<nbins-1){
+         entriesI +=  his->GetBinContent(ibin+delta);
+         countB++;
+       }
+      }
+      entriesI/=countB;
+      Double_t xcenter= his->GetBinCenter(ibin);
+      if (xcenter<xmin || xcenter>xmax) continue;
+      Double_t error=1./TMath::Sqrt(countB);
+      Float_t   cont=2;
+      if (iter>0){
+       if (par[0]+par[1]*xcenter+par[2]*xcenter*xcenter>20) return 0;
+       cont = TMath::Exp(par[0]+par[1]*xcenter+par[2]*xcenter*xcenter);
+       if (cont>1.) error = 1./TMath::Sqrt(cont*Float_t(countB));
+      }
+      if (entriesI>1&&cont>1){
+       fitter.AddPoint(&xcenter,TMath::Log(Float_t(entriesI)),error);
+       npoints++;
+      }
+    }  
+    if (npoints>3){
+      fitter.Eval();
+      fitter.GetParameters(par);
+    }else{
+      break;
+    }
+  }
+  if (npoints<=3){
+    return -1;
+  }
+  fitter.GetParameters(par);
+  fitter.GetCovarianceMatrix(mat);
+  if (TMath::Abs(par[1])<mat.GetTol()) return -1;
+  if (TMath::Abs(par[2])<mat.GetTol()) return -1;
+  Double_t chi2 = fitter.GetChisquare()/Float_t(npoints);
+  //fitter.GetParameters();
+  if (!param)  param  = new TVectorD(3);
+  if (!matrix) matrix = new TMatrixD(3,3);
+  (*param)[1] = par[1]/(-2.*par[2]);
+  (*param)[2] = 1./TMath::Sqrt(TMath::Abs(-2.*par[2]));
+  (*param)[0] = TMath::Exp(par[0]+ par[1]* (*param)[1] +  par[2]*(*param)[1]*(*param)[1]);
+  if (verbose){
+    par.Print();
+    mat.Print();
+    param->Print();
+    printf("Chi2=%f\n",chi2);
+    TF1 * f1= new TF1("f1","[0]*exp(-(x-[1])^2/(2*[2]*[2]))",his->GetXaxis()->GetXmin(),his->GetXaxis()->GetXmax());
+    f1->SetParameter(0, (*param)[0]);
+    f1->SetParameter(1, (*param)[1]);
+    f1->SetParameter(2, (*param)[2]);    
+    f1->Draw("same");
+  }
+  return chi2;
+}
+
+

diff --git a/STEER/AliMathBase.h b/STEER/AliMathBase.h
index 75df06ddec39538dcee5816317d99c90551e2ac7..dc9ef25c7b9c26cd95283dee8e649082876b81a0 100644 (file)
--- a/STEER/AliMathBase.h
+++ b/STEER/AliMathBase.h
@@ -6,7 +6,10 @@
 
  
 #include "TObject.h"
+#include "TVectorD.h"
+#include "TMatrixD.h"
 
+class TH1F;
  
 class AliMathBase : public TObject
 {
@@ -16,7 +19,10 @@ class AliMathBase : public TObject
   static void    EvaluateUni(Int_t nvectors, Double_t *data, Double_t &mean, Double_t &sigma, Int_t hh);
   static void    EvaluateUniExternal(Int_t nvectors, Double_t *data, Double_t &mean, Double_t &sigma, Int_t hh, Float_t externalfactor=1);
   static Int_t  Freq(Int_t n, const Int_t *inlist, Int_t *outlist, Bool_t down);    
-
+  static  void TruncatedMean(TH1F * his, TVectorD *param, Float_t down=0, Float_t up=1.0, Bool_t verbose=kFALSE);
+  static void LTM(TH1F * his, TVectorD *param=0 , Float_t fraction=1,  Bool_t verbose=kFALSE);
+  static Double_t  FitGaus(TH1F* his, TVectorD *param=0, TMatrixD *matrix=0, Float_t xmin=0, Float_t xmax=0,  Bool_t verbose=kFALSE);
+    
  ClassDef(AliMathBase,0) // Various mathematical tools for physics analysis - which are not included in ROOT TMath
  
 };