1 | // main62.cc is a part of the PYTHIA event generator. |
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2 | // Copyright (C) 2012 Mikhail Kirsanov, Torbjorn Sjostrand. |
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3 | // PYTHIA is licenced under the GNU GPL version 2, see COPYING for details. |
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4 | // Please respect the MCnet Guidelines, see GUIDELINES for details. |
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5 | |
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6 | // This is a simple test program. |
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7 | // It illustrates how a file with HepMC events can be generated by Pythia8. |
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8 | // It is similar to main42, except that it is compiled with LHAPDF |
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9 | // and allows for several subruns, e.g. from related LHEF. |
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10 | // Input and output files are specified on the command line, e.g. like |
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11 | // ./main62.exe main62.cmnd hepmcout62.dat > out |
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12 | // The main program contains no analysis; this is intended to happen later. |
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13 | // It therefore "never" has to be recompiled to handle different tasks. |
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14 | |
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15 | // WARNING: typically one needs 25 MB/100 events at the LHC. |
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16 | // Therefore large event samples may be impractical. |
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17 | |
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18 | #include "Pythia.h" |
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19 | #include "HepMCInterface.h" |
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20 | |
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21 | #include "HepMC/GenEvent.h" |
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22 | #include "HepMC/IO_GenEvent.h" |
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23 | |
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24 | // Following line is a deprecated alternative, removed in recent versions. |
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25 | //#include "HepMC/IO_Ascii.h" |
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26 | //#include "HepMC/IO_AsciiParticles.h" |
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27 | |
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28 | // Following line to be used with HepMC 2.04 onwards. |
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29 | #ifdef HEPMC_HAS_UNITS |
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30 | #include "HepMC/Units.h" |
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31 | #endif |
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32 | |
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33 | using namespace Pythia8; |
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34 | |
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35 | int main(int argc, char* argv[]) { |
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36 | |
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37 | // Check that correct number of command-line arguments |
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38 | if (argc != 3) { |
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39 | cerr << " Unexpected number of command-line arguments. \n You are" |
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40 | << " expected to provide one input and one output file name. \n" |
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41 | << " Program stopped! " << endl; |
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42 | return 1; |
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43 | } |
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44 | |
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45 | // Check that the provided input name corresponds to an existing file. |
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46 | ifstream is(argv[1]); |
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47 | if (!is) { |
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48 | cerr << " Command-line file " << argv[1] << " was not found. \n" |
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49 | << " Program stopped! " << endl; |
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50 | return 1; |
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51 | } |
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52 | |
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53 | // Confirm that external files will be used for input and output. |
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54 | cout << "\n >>> PYTHIA settings will be read from file " << argv[1] |
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55 | << " <<< \n >>> HepMC events will be written to file " |
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56 | << argv[2] << " <<< \n" << endl; |
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57 | |
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58 | // Interface for conversion from Pythia8::Event to HepMC one. |
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59 | HepMC::I_Pythia8 ToHepMC; |
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60 | // ToHepMC.set_crash_on_problem(); |
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61 | |
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62 | // Specify file where HepMC events will be stored. |
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63 | HepMC::IO_GenEvent ascii_io(argv[2], std::ios::out); |
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64 | // Following line is a deprecated alternative, removed in recent versions |
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65 | // HepMC::IO_Ascii ascii_io("hepmcout32.dat", std::ios::out); |
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66 | // Line below is an eye-readable one-way output, uncomment the include above |
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67 | // HepMC::IO_AsciiParticles ascii_io("hepmcout32.dat", std::ios::out); |
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68 | |
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69 | // Generator. |
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70 | Pythia pythia; |
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71 | |
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72 | // Read in subrun-independent commands from external file. |
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73 | pythia.readFile( argv[1]); |
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74 | |
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75 | // Extract data to be used in main program. Set counters. |
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76 | int nSubrun = pythia.mode("Main:numberOfSubruns"); |
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77 | int nAbort = pythia.mode("Main:timesAllowErrors"); |
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78 | int iAbort = 0; |
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79 | |
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80 | // Begin loop over subruns. |
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81 | for (int iSubrun = 1; iSubrun <= nSubrun; ++iSubrun) { |
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82 | |
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83 | // Read in subrun-specific data from external file. |
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84 | pythia.readFile( argv[1], iSubrun); |
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85 | |
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86 | // Initialization. |
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87 | pythia.init(); |
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88 | |
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89 | // Print name of Les Houches Event File. |
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90 | string lheFile = pythia.settings.word("Beams:LHEF"); |
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91 | cout << "\n >>> Now begin subrun " << iSubrun |
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92 | << " with events from file " << lheFile << " <<< \n" |
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93 | << endl; |
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94 | |
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95 | // Begin infinite event loop - to be exited at end of file. |
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96 | for (int iEvent = 0; ; ++iEvent) { |
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97 | |
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98 | // Generate event. |
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99 | if (!pythia.next()) { |
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100 | |
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101 | // Leave event loop if at end of file. |
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102 | if (pythia.info.atEndOfFile()) break; |
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103 | |
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104 | // First few failures write off as "acceptable" errors, then quit. |
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105 | if (++iAbort < nAbort) continue; |
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106 | cout << " Event generation aborted prematurely, owing to error!\n"; |
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107 | break; |
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108 | } |
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109 | |
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110 | // Construct new empty HepMC event. |
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111 | #ifdef HEPMC_HAS_UNITS |
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112 | // This form with arguments is only meaningful for HepMC 2.04 onwards, |
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113 | // and even then unnecessary if HepMC was built with GeV and mm as units. |
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114 | HepMC::GenEvent* hepmcevt = new HepMC::GenEvent( |
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115 | HepMC::Units::GEV, HepMC::Units::MM); |
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116 | #else |
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117 | // This form is needed for backwards compatibility. |
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118 | // In HepMCInterface.cc a conversion from GeV to MeV will be done. |
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119 | HepMC::GenEvent* hepmcevt = new HepMC::GenEvent(); |
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120 | #endif |
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121 | |
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122 | // Fill HepMC event, including PDF info. |
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123 | ToHepMC.fill_next_event( pythia, hepmcevt ); |
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124 | // This alternative older method fills event, without PDF info. |
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125 | // ToHepMC.fill_next_event( pythia.event, hepmcevt ); |
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126 | |
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127 | // Write the HepMC event to file. Done with it. |
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128 | ascii_io << hepmcevt; |
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129 | delete hepmcevt; |
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130 | |
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131 | // End of event loop. |
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132 | } |
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133 | |
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134 | // End of subrun loop. |
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135 | } |
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136 | |
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137 | // Statistics. |
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138 | pythia.stat(); |
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139 | |
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140 | // Done. |
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141 | return 0; |
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142 | } |
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