Import Geant4 11.2.0.beta source tree

2023-06-30 09:09:57 +02:00
parent aef78ca386
commit dd1f179cda
3780 changed files with 212808 additions and 142780 deletions
@@ -0,0 +1,98 @@
+//
+// ********************************************************************
+// * License and Disclaimer                                           *
+// *                                                                  *
+// * The  Geant4 software  is  copyright of the Copyright Holders  of *
+// * the Geant4 Collaboration.  It is provided  under  the terms  and *
+// * conditions of the Geant4 Software License,  included in the file *
+// * LICENSE and available at  http://cern.ch/geant4/license .  These *
+// * include a list of copyright holders.                             *
+// *                                                                  *
+// * Neither the authors of this software system, nor their employing *
+// * institutes,nor the agencies providing financial support for this *
+// * work  make  any representation or  warranty, express or implied, *
+// * regarding  this  software system or assume any liability for its *
+// * use.  Please see the license in the file  LICENSE  and URL above *
+// * for the full disclaimer and the limitation of liability.         *
+// *                                                                  *
+// * This  code  implementation is the result of  the  scientific and *
+// * technical work of the GEANT4 collaboration.                      *
+// * By using,  copying,  modifying or  distributing the software (or *
+// * any work based  on the software)  you  agree  to acknowledge its *
+// * use  in  resulting  scientific  publications,  and indicate your *
+// * acceptance of all terms of the Geant4 Software license.          *
+// ********************************************************************
+//
+////////////////////////////////////////////////////////////////////////////////
+//                                                                            //
+//  File:   G4BetaSpectrumSampler.cc                                          //
+//  Author: D.H. Wright                                                       //
+//  Date:   21 November 2022                                                  //
+//  Description: samples a spectrum which is a piece-wise linear function of  //
+//               energy. The CDF is calculated by trapezoidal integration     //
+//               and within bins the line y = mx + b is sampled.              //
+//                                                                            //
+////////////////////////////////////////////////////////////////////////////////
+
+#include "G4BetaSpectrumSampler.hh"
+
+G4BetaSpectrumSampler::
+G4BetaSpectrumSampler(const G4double* aPDF, G4int pdfSize, G4double e)
+{
+  pdf.resize(pdfSize);
+  nBins = pdfSize-1;
+  cdf.resize(nBins);
+  eEnd = e;
+
+  lowerBinEdge = 0;
+  upperBinEdge = 1;
+
+  for (G4int i = 0; i < pdfSize; i++) pdf[i] = aPDF[i];
+
+  // Caclulate binwise CDF using trapezoidal integration
+  G4double sum = pdf[0]/2.;
+  for (G4int i = 1; i < pdfSize; i++) {
+    sum += pdf[i];
+    cdf[i-1] = sum - pdf[i]/2.;
+  }
+}
+
+G4double G4BetaSpectrumSampler::shoot()
+{
+  G4double rand = G4UniformRand()*cdf[nBins-1];
+  G4int ibin = 0;
+
+  while (rand > cdf[ibin]) ibin++;
+
+  G4double x = nBins;
+  if (ibin < nBins) {
+    lowerBinEdge = ibin;
+    upperBinEdge = ibin+1;
+    x = sampleSlopedLine();
+  }
+
+  return x/nBins;
+}
+
+
+G4double G4BetaSpectrumSampler::sampleSlopedLine()
+{
+  G4double x;
+  G4double rand = G4UniformRand();
+  ylower = pdf[lowerBinEdge];
+  yupper = pdf[upperBinEdge];
+
+  if (std::abs(2.*(yupper - ylower)/(yupper + ylower) ) < 1.E-6) {
+    // Slope is near zero, sample flat
+    x = lowerBinEdge + rand*(upperBinEdge - lowerBinEdge);
+
+  } else {
+    // Sample incline
+    x = (yupper*lowerBinEdge - ylower*upperBinEdge +
+         std::sqrt(ylower*ylower + rand*(yupper*yupper - ylower*ylower) ) )
+        /(yupper - ylower);
+  }
+
+  return x;
+}
+