Fix in the printout of the validity time-stamps

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

diff --git a/STEER/AliMathBase.cxx b/STEER/AliMathBase.cxx
index 03e2b4167e12f2e7e2b0eea0b3c7da9b638868a7..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
 //
@@ -552,6 +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 /////////////////////////
@@ -768,57 +783,5 @@ Double_t AliMathBase::BetheBlochAleph(Double_t bg,
   // The returned value is in MIP units
   //
 
-  Double_t beta = bg/TMath::Sqrt(1.+ bg*bg);
-
-  Double_t aa = TMath::Power(beta,kp4);
-  Double_t bb = TMath::Power(1./bg,kp5);
-
-  bb=TMath::Log(kp3+bb);
-  
-  return (kp2-aa-bb)*kp1/aa;
-}
-
-Double_t AliMathBase::BetheBlochGeant(Double_t bg,
-         Double_t kp0,
-         Double_t kp1,
-         Double_t kp2,
-         Double_t kp3,
-         Double_t kp4) {
-  //
-  // This is the parameterization of the Bethe-Bloch formula inspired by Geant.
-  //
-  // bg  - beta*gamma
-  // kp0 - density [g/cm^3]
-  // kp1 - density effect first junction point
-  // kp2 - density effect second junction point
-  // kp3 - mean excitation energy [GeV]
-  // kp4 - mean Z/A
-  //
-  // The default values for the kp* parameters are for silicon. 
-  // The returned value is in [GeV/(g/cm^2)].
-  // 
-
-  const Double_t mK  = 0.307075e-3; // [GeV*cm^2/g]
-  const Double_t me  = 0.511e-3;    // [GeV/c^2]
-  const Double_t rho = kp0;
-  const Double_t x0  = kp1*2.303;
-  const Double_t x1  = kp2*2.303;
-  const Double_t mI  = kp3;
-  const Double_t mZA = kp4;
-  const Double_t bg2 = bg*bg;
-  const Double_t maxT= 2*me*bg2;    // neglecting the electron mass
-  
-  //*** Density effect
-  Double_t d2=0.; 
-  const Double_t x=TMath::Log(bg);
-  const Double_t lhwI=TMath::Log(28.816*1e-9*TMath::Sqrt(rho*mZA)/mI);
-  if (x > x1) {
-    d2 = lhwI + x - 0.5;
-  } else if (x > x0) {
-    const Double_t r=(x1-x)/(x1-x0);
-    d2 = lhwI + x - 0.5 + (0.5 - lhwI - x0)*r*r*r;
-  }
-
-  return mK*mZA*(1+bg2)/bg2*
-         (0.5*TMath::Log(2*me*bg2*maxT/(mI*mI)) - bg2/(1+bg2) - d2);
+  return AliExternalTrackParam::BetheBlochAleph(bg,kp1,kp2,kp3,kp4,kp5);
 }