AnaMelaHelpers Namespace Reference

Functions
void	multiplyComplexNumbers (std::vector< Double_t > const &reals, std::vector< Double_t > const &imags, Double_t &resRe, Double_t &resIm)

Function Documentation

multiplyComplexNumbers()

void AnaMelaHelpers::multiplyComplexNumbers	(	std::vector< Double_t > const &	reals,
		std::vector< Double_t > const &	imags,
		Double_t &	resRe,
		Double_t &	resIm
	)

Definition at line 7 of file RooSpin.cc.

                                                                                                                                               {
  resRe=0; resIm=0;
  const unsigned int nreals = reals.size();
  const unsigned int nimags = imags.size();
  const unsigned int nloops = pow(2, min(nreals, nimags));
  const unsigned int nterms = max(nreals, nimags);
 
  for (unsigned int ic=0; ic<nloops; ic++){
    Double_t termval=1;
    unsigned int nimagsused=0;
    bool doSkip=false;
    for (unsigned int it=0; it<nterms; it++){
      unsigned int code = (nreals>=nimags ? 0 : 1);
      if (it<nloops) code = (ic >> it);
      if (code%2==1){
        nimagsused++;
        termval*=imags.at(it);
      }
      else termval*=reals.at(it);
      if (termval==0.){ doSkip=true; break; }
    }
    if (doSkip) continue;
    if (nimagsused%4==0) resRe += termval;
    else if (nimagsused%4==1) resIm += termval;
    else if (nimagsused%4==2) resRe -= termval;
    else resIm -= termval;
  }
}