Coverity fix.

[u/mrichter/AliRoot.git] / STEER / AliMathBase.cxx

diff --git a/STEER/AliMathBase.cxx b/STEER/AliMathBase.cxx
index 13e7e69ecd180781c6ff1c36cf6602d89ce075fe..cdae2369d06d0477342b06bbae8e26c2f9a8c7d2 100644 (file)
--- a/STEER/AliMathBase.cxx
+++ b/STEER/AliMathBase.cxx
@@ -29,6 +29,8 @@
 #include "TF1.h"
 #include "TLinearFitter.h"
 
+#include "AliExternalTrackParam.h"
+
 //
 // includes neccessary for test functions
 //
@@ -378,7 +380,7 @@ Double_t  AliMathBase::FitGaus(Float_t *arr, Int_t nBins, Float_t xMin, Float_t
   //  Prameters:
   //     nbins: size of the array and number of histogram bins
   //     xMin, xMax: histogram range
-  //     param: paramters of the fit (0-Constant, 1-Mean, 2-Sigma)
+  //     param: paramters of the fit (0-Constant, 1-Mean, 2-Sigma, 3-Sum)
   //     matrix: covariance matrix -- not implemented yet, pass dummy matrix!!!
   //
   //  Return values:
@@ -416,20 +418,22 @@ Double_t  AliMathBase::FitGaus(Float_t *arr, Int_t nBins, Float_t xMin, Float_t
       entries+=arr[i];
       if (arr[i]>0) nfilled++;
   }
+  (*param)[0] = 0;
+  (*param)[1] = 0;
+  (*param)[2] = 0;
+  (*param)[3] = 0;
 
   if (max<4) return -4;
   if (entries<12) return -4;
   if (rms<kTol) return -4;
 
-  Int_t npoints=0;
-  //
+  (*param)[3] = entries;
 
-  //
+  Int_t npoints=0;
   for (Int_t ibin=0;ibin<nBins; ibin++){
       Float_t entriesI = arr[ibin];
     if (entriesI>1){
       Double_t xcenter = xMin+(ibin+0.5)*binWidth;
-      
       Float_t error    = 1./TMath::Sqrt(entriesI);
       Float_t val = TMath::Log(Float_t(entriesI));
       fitter.AddPoint(&xcenter,val,error);
@@ -445,7 +449,6 @@ Double_t  AliMathBase::FitGaus(Float_t *arr, Int_t nBins, Float_t xMin, Float_t
       npoints++;
     }
   }
-
   
   Double_t chi2 = 0;
   if (npoints>=3){
@@ -468,7 +471,8 @@ Double_t  AliMathBase::FitGaus(Float_t *arr, Int_t nBins, Float_t xMin, Float_t
       if (TMath::Abs(par[1])<kTol) return -4;
       if (TMath::Abs(par[2])<kTol) return -4;
 
-      if (!param)  param  = new TVectorD(3);
+      if (!param)  param  = new TVectorD(4);
+      if ( param->GetNrows()<4 ) param->ResizeTo(4);
       if (!matrix) matrix = new TMatrixD(3,3);  // !!!!might be a memory leek. use dummy matrix pointer to call this function!
 
       (*param)[1] = par[1]/(-2.*par[2]);
@@ -550,6 +554,19 @@ Float_t AliMathBase::GetCOG(Short_t *arr, Int_t nBins, Float_t xMin, Float_t xMa
 }
 
 
+Double_t AliMathBase::ErfcFast(Double_t x){
+  // Fast implementation of the complementary error function
+  // The error of the approximation is |eps(x)| < 5E-4
+  // See Abramowitz and Stegun, p.299, 7.1.27
+
+  Double_t z = TMath::Abs(x);
+  Double_t ans = 1+z*(0.278393+z*(0.230389+z*(0.000972+z*0.078108)));
+  ans = 1.0/ans;
+  ans *= ans;
+  ans *= ans;
+
+  return (x>=0.0 ? ans : 2.0 - ans);
+}
 
 ///////////////////////////////////////////////////////////////
 //////////////         TEST functions /////////////////////////
@@ -726,3 +743,45 @@ TGraph * AliMathBase::MakeStat1D(TH3 * his, Int_t delta1, Int_t type){
   }
   return graph;
 }
+
+Double_t AliMathBase::TruncatedGaus(Double_t mean, Double_t sigma, Double_t cutat)
+{
+  // return number generated according to a gaussian distribution N(mean,sigma) truncated at cutat
+  //
+  Double_t value;
+  do{
+    value=gRandom->Gaus(mean,sigma);
+  }while(TMath::Abs(value-mean)>cutat);
+  return value;
+}
+
+Double_t AliMathBase::TruncatedGaus(Double_t mean, Double_t sigma, Double_t leftCut, Double_t rightCut)
+{
+  // return number generated according to a gaussian distribution N(mean,sigma)
+  // truncated at leftCut and rightCut
+  //
+  Double_t value;
+  do{
+    value=gRandom->Gaus(mean,sigma);
+  }while((value-mean)<-leftCut || (value-mean)>rightCut);
+  return value;
+}
+
+Double_t AliMathBase::BetheBlochAleph(Double_t bg,
+         Double_t kp1,
+         Double_t kp2,
+         Double_t kp3,
+         Double_t kp4,
+         Double_t kp5) {
+  //
+  // This is the empirical ALEPH parameterization of the Bethe-Bloch formula.
+  // It is normalized to 1 at the minimum.
+  //
+  // bg - beta*gamma
+  // 
+  // The default values for the kp* parameters are for ALICE TPC.
+  // The returned value is in MIP units
+  //
+
+  return AliExternalTrackParam::BetheBlochAleph(bg,kp1,kp2,kp3,kp4,kp5);
+}