EvtAmpIndex.cc

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//--------------------------------------------------------------------------
//
// Environment:
//      This software is part of the EvtGen package developed jointly
//      for the BaBar and CLEO collaborations.  If you use all or part
//      of it, please give an appropriate acknowledgement.
//
// Copyright Information: See EvtGen/COPYRIGHT
//      Copyright (C) 2002      Caltech
//
// Module: EvtAmp.cc
//
// Description: Class to manipulate the amplitudes in the decays.
//
// Modification history:
//
//    RYD     Nov 22, 2002         Module created
//
//------------------------------------------------------------------------
//
#include "EvtAmpIndex.hh"
#include "EvtPatches.hh"
#include <vector>
using std::vector;
 
EvtAmpIndex::EvtAmpIndex( std::vector<int> ind )
    : _ind( ind ), _size( ind.size() ), _state( ind.size() ), _nstate( ind.size() ) {
  int i;
 
  for ( i = 0; i < _size; i++ )
  {
    _state[i] = 0;
    if ( i == 0 ) { _nstate[i] = 1; }
    else { _nstate[i] = _nstate[i - 1] * _ind[i]; }
  }
}
 
void EvtAmpIndex::reset() {
  int i;
  for ( i = 0; i < _size; i++ ) { _state[i] = 0; }
}
 
bool EvtAmpIndex::next() {
  int i;
  for ( i = 0; i < _size; i++ )
  {
    _state[i]++;
    if ( _state[i] < _ind[i] ) { return true; }
    else { _state[i] = 0; }
  }
  return false;
}
 
int EvtAmpIndex::index() {
 
  int i;
  int ind = 0;
 
  for ( i = 0; i < _size; i++ ) { ind += _state[i] * _nstate[i]; }
 
  return ind;
}