Grid/lib/qcd/action/fermion/OverlapWilsonContfracZolotarevFermion.h

    /*************************************************************************************

    Grid physics library, www.github.com/paboyle/Grid 

    Source file: ./lib/qcd/action/fermion/OverlapWilsonContfracZolotarevFermion.h

    Copyright (C) 2015

Author: Peter Boyle <pabobyle@ph.ed.ac.uk>
Author: Peter Boyle <paboyle@ph.ed.ac.uk>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

    See the full license in the file "LICENSE" in the top level distribution directory
    *************************************************************************************/
    /*  END LEGAL */
#ifndef OVERLAP_WILSON_CONTFRAC_ZOLOTAREV_FERMION_H
#define OVERLAP_WILSON_CONTFRAC_ZOLOTAREV_FERMION_H

#include <Grid/Grid.h>

namespace Grid {

  namespace QCD {

    template<class Impl>
    class OverlapWilsonContFracZolotarevFermion : public ContinuedFractionFermion5D<Impl>
    {
    public:
     INHERIT_IMPL_TYPES(Impl);

      virtual void   Instantiatable(void){};
      // Constructors
    OverlapWilsonContFracZolotarevFermion(GaugeField &_Umu,
					  GridCartesian         &FiveDimGrid,
					  GridRedBlackCartesian &FiveDimRedBlackGrid,
					  GridCartesian         &FourDimGrid,
					  GridRedBlackCartesian &FourDimRedBlackGrid,
					  RealD _mass,RealD _M5,
					  RealD lo,RealD hi,const ImplParams &p= ImplParams()):
      
      // b+c=scale, b-c = 0 <=> b =c = scale/2
      ContinuedFractionFermion5D<Impl>(_Umu,
				       FiveDimGrid,
				       FiveDimRedBlackGrid,
				       FourDimGrid,
				       FourDimRedBlackGrid,_mass,_M5,p)
	{
	  assert((this->Ls&0x1)==1); // Odd Ls required

	  int nrational=this->Ls;// Odd rational order
	  RealD eps = lo/hi;

	  Approx::zolotarev_data *zdata = Approx::zolotarev(eps,nrational,0);
	  this->SetCoefficientsZolotarev(hi,zdata);
	  Approx::zolotarev_free(zdata);

	}
    };
  }
}
#endif