filters.cc

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#define TF_FILTER_CC_VERSION \
  "TF_FILTER_CC   V1.0"

#include <fourier/filters.h>
#include <fourier/error.h>
#include <cmath>

namespace fourier {

  const double Filter::pi=M_PI;
  const Filter::Tcvalue Filter::ime=Tcvalue(0.,1.);

  /*----------------------------------------------------------------------*/

  Filter::Tcvalue Filter::omega(const Filter::Tcvalue& par) const 
  {
    Tcvalue retval;
    if (isfreqmod()) { retval=2.*pi*par; } else { retval=2.*pi/par; }
    return(retval);
  }

  /*----------------------------------------------------------------------*/

  void Filter::setint()
  {
     this->Tbase::setpole(Tcvalue(0.,0.));
     this->Tbase::denfactor(Tcvalue(0.,1.));
  }

  /*----------------------------------------------------------------------*/

  void Filter::setdif()
  {
     this->Tbase::setzero(Tcvalue(0.,0.));
     this->Tbase::numfactor(Tcvalue(0.,1.));
  }

  /*----------------------------------------------------------------------*/

  void Filter::sethpb(const Filter::Tcvalue& par, const int& ord) 
  {
    Tcvalue om=omega(par);
    FOURIER_assert((ord>0), "ERROR (Filter hpb): illegal order!");
    for (int i=1; i<=ord; ++i)
    {
      this->Tbase::setzero(Tcvalue(0.,0.));
      Tcvalue pole=om*std::exp(ime*pi*(2.*i-1.)/(2.*ord));
      this->Tbase::setpole(pole);
    }
  }

  /*----------------------------------------------------------------------*/

  void Filter::setlpb(const Filter::Tcvalue& par, const int& ord) 
  {
    Tcvalue om=omega(par);
    FOURIER_assert((ord>0), "ERROR (Filter lpb): illegal order!");
    for (int i=1; i<=ord; ++i)
    {
      this->Tbase::numfactor(-ime*om);
      Tcvalue pole=om*std::exp(ime*pi*(2.*i-1.)/(2.*ord));
      this->Tbase::setpole(pole);
    }
  }

  /*----------------------------------------------------------------------*/

  void Filter::sethp2(const Filter::Tcvalue& par, const double& h) 
  {
    Tcvalue om=omega(par);
    this->Tbase::setzero(Tcvalue(0.,0.));
    this->Tbase::setzero(Tcvalue(0.,0.));
    Tcvalue pole=om*(ime*h+std::sqrt(1.-h*h));
    this->Tbase::setpole(pole);
    pole=om*(ime*h-std::sqrt(1.-h*h));
    this->Tbase::setpole(pole);
  }

  /*----------------------------------------------------------------------*/

  void Filter::setlp2(const Filter::Tcvalue& par, const double& h) 
  {
    Tcvalue om=omega(par);
    this->Tbase::numfactor(-ime*om);
    this->Tbase::numfactor(-ime*om);
    Tcvalue pole=om*(ime*h+std::sqrt(1.-h*h));
    this->Tbase::setpole(pole);
    pole=om*(ime*h-std::sqrt(1.-h*h));
    this->Tbase::setpole(pole);
  }

} // namespace fourier

/* ----- END OF filter.cc ----- */