Geant4  10.02.p02
G4AngularDistributionNP.cc
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27 #include "G4PhysicalConstants.hh"
28 #include "G4SystemOfUnits.hh"
29 #include "Randomize.hh"
30 #include "G4ios.hh"
31 
32 // Initialization of static data arrays:
34 #include "Randomize.hh"
35 
36 
38 {
39  G4int verboseLevel=1;
40 
41  G4double ek= ((S - sqr(m_1) -sqr(m_2) )/(2*m_1) - m_1 )/GeV ; // kinetic energy in GeV
42 
43  // Find energy bin
44 
45  G4int je1 = 0;
46  G4int je2 = NENERGY - 1;
47  G4int iterationsLeft=2*NENERGY +1;
48  do {
49  G4int midBin = (je1 + je2)/2;
50  if (ek < elab[midBin])
51  je2 = midBin;
52  else
53  je1 = midBin;
54  } while ( (je2 - je1) > 1 && --iterationsLeft > 0 ); /* Loop checking, 30-Oct-2015, G.Folger */
55  if ( iterationsLeft <= 0 ) {
56  G4Exception("G4AngularDistributionNP", "im_r_matrix010", FatalException,
57  "Problem with energy bin (elab) data");
58 
59  }
60  // G4int j;
61  //std::abs(ek-elab[je1]) < std::abs(ek-elab[je2]) ? j = je1 : j = je2;
62  G4double delab = elab[je2] - elab[je1];
63 
64  // Sample the angle
65 
66  G4double sample = G4UniformRand();
67  G4int ke1 = 0;
68  G4int ke2 = NANGLE - 1;
69  G4double dsig = sig[je2][0] - sig[je1][0];
70  G4double rc = dsig/delab;
71  G4double b = sig[je1][0] - rc*elab[je1];
72  G4double sigint1 = rc*ek + b;
73  G4double sigint2 = 0.;
74 
75  if (verboseLevel > 1) G4cout << "sample=" << sample << G4endl
76  << ek << " " << ke1 << " " << ke2 << " "
77  << sigint1 << " " << sigint2 << G4endl;
78  iterationsLeft= 2*NANGLE +1;
79  do {
80  G4int midBin = (ke1 + ke2)/2;
81  dsig = sig[je2][midBin] - sig[je1][midBin];
82  rc = dsig/delab;
83  b = sig[je1][midBin] - rc*elab[je1];
84  G4double sigint = rc*ek + b;
85  if (sample < sigint) {
86  ke2 = midBin;
87  sigint2 = sigint;
88  }
89  else {
90  ke1 = midBin;
91  sigint1 = sigint;
92  }
93  if (verboseLevel > 1)G4cout << ke1 << " " << ke2 << " "
94  << sigint1 << " " << sigint2 << G4endl;
95  } while ( (ke2 - ke1) > 1 && --iterationsLeft > 0); /* Loop checking, 30-Oct-2015, G.Folger */
96  if ( iterationsLeft <= 0 ) {
97  G4Exception("G4AngularDistributionNP", "im_r_matrix011", FatalException,
98  "Problem with angular distribution (sig) data");
99  }
100 
101  // sigint1 and sigint2 should be recoverable from above loop
102 
103  // G4double dsig = sig[je2][ke1] - sig[je1][ke1];
104  // G4double rc = dsig/delab;
105  // G4double b = sig[je1][ke1] - rc*elab[je1];
106  // G4double sigint1 = rc*ek + b;
107 
108  // G4double dsig = sig[je2][ke2] - sig[je1][ke2];
109  // G4double rc = dsig/delab;
110  // G4double b = sig[je1][ke2] - rc*elab[je1];
111  // G4double sigint2 = rc*ek + b;
112 
113  dsig = sigint2 - sigint1;
114  rc = 1./dsig;
115  b = ke1 - rc*sigint1;
116  G4double kint = rc*sample + b;
117  G4double theta = (0.5 + kint)*pi/180.;
118 
119  // G4int k;
120  //std::abs(sample-sig[j][ke1]) < std::abs(sample-sig[j][ke2]) ? k = ke1 : k = ke2;
121  // G4double theta = (0.5 + k)*pi/180.;
122 
123  if (verboseLevel > 1) {
124  G4cout << " energy bin " << je1 << " energy=" << elab[je1] << G4endl;
125  G4cout << " angle bin " << kint << " angle=" << theta/degree << G4endl;
126  }
127  G4double costh= std::cos(theta);
128  return costh;
129 }
130 
132 {
133  return twopi * G4UniformRand();
134 }
double S(double temp)
int G4int
Definition: G4Types.hh:78
#define G4UniformRand()
Definition: Randomize.hh:97
G4GLOB_DLL std::ostream G4cout
static const double twopi
Definition: G4SIunits.hh:75
static const double GeV
Definition: G4SIunits.hh:214
void G4Exception(const char *originOfException, const char *exceptionCode, G4ExceptionSeverity severity, const char *comments)
Definition: G4Exception.cc:41
virtual G4double CosTheta(G4double s, G4double m1, G4double m2) const
static const double pi
Definition: G4SIunits.hh:74
static const G4float elab[NENERGY]
virtual G4double Phi() const
static const double degree
Definition: G4SIunits.hh:143
#define G4endl
Definition: G4ios.hh:61
T sqr(const T &x)
Definition: templates.hh:145
double G4double
Definition: G4Types.hh:76
static const G4float sig[NENERGY][NANGLE]