pt_source_const.cc

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/*! \file
 *  \brief Point source construction
 */
 
#include "chromabase.h"
#include "handle.h"
 
#include "meas/sources/source_const_factory.h"
#include "meas/sources/pt_source_const.h"
#include "meas/sources/srcfil.h"
#include "meas/smear/link_smearing_aggregate.h"
#include "meas/smear/link_smearing_factory.h"
#include "meas/smear/quark_displacement_aggregate.h"
#include "meas/smear/quark_displacement_factory.h"
#include "util/ferm/transf.h"
 
#include "meas/smear/simple_quark_displacement.h"
 
namespace Chroma
{
  // Read parameters
  void read(XMLReader& xml, const std::string& path, PointQuarkSourceConstEnv::Params& param)
  {
    PointQuarkSourceConstEnv::Params tmp(xml, path);
    param = tmp;
  }
 
  // Writer
  void write(XMLWriter& xml, const std::string& path, const PointQuarkSourceConstEnv::Params& param)
  {
    param.writeXML(xml, path);
  }
 
 
 
  //! Hooks to register the class
  namespace PointQuarkSourceConstEnv
  {
    namespace
    {
      //! Callback function
      QuarkSourceConstruction<LatticePropagator>* createProp(XMLReader& xml_in,
                                                             const std::string& path)
      {
        return new SourceConst<LatticePropagator>(Params(xml_in, path));
      }
      
      //! Callback function
      QuarkSourceConstruction<LatticeStaggeredPropagator>* createStagProp(XMLReader& xml_in,
                                                                      const std::string& path)
      {
        return new SourceConst<LatticeStaggeredPropagator>(Params(xml_in, path));
      }
      
      //! Local registration flag
      bool registered = false;
 
      //! Name to be used
      const std::string name("POINT_SOURCE");
    }
 
    //! Return the name
    std::string getName() {return name;}
 
    //! Register all the factories
    bool registerAll() 
    {
      bool success = true; 
      if (! registered)
      {
        success &= LinkSmearingEnv::registerAll();
        success &= QuarkDisplacementEnv::registerAll();
        success &= Chroma::ThePropSourceConstructionFactory::Instance().registerObject(name, createProp);
        success &= Chroma::TheStagPropSourceConstructionFactory::Instance().registerObject(name, createStagProp);
        registered = true;
      }
      return success;
    }
 
    //! Initialize
    Params::Params()
    {
      j_decay = -1;
      t_srce.resize(Nd);
      t_srce = 0;
    }
 
 
    //! Read parameters
    Params::Params(XMLReader& xml, const std::string& path)
    {
      XMLReader paramtop(xml, path);
 
      int version;
      read(paramtop, "version", version);
 
      switch (version) 
      {
      case 1:
      {
        quark_displacement = QuarkDisplacementEnv::nullXMLGroup();
        quark_displacement.id = SimpleQuarkDisplacementEnv::getName();
        int disp_length = 0;
        int disp_dir = 0;
 
        XMLBufferWriter xml_tmp;
        push(xml_tmp, "Displacement");
        write(xml_tmp, "DisplacementType", quark_displacement.id);
 
        if (paramtop.count("disp_length") != 0)
          read(paramtop, "disp_length", disp_length);
 
        if (paramtop.count("disp_dir") != 0)
          read(paramtop, "disp_dir", disp_dir);
 
        write(xml_tmp, "disp_length", disp_length);
        write(xml_tmp, "disp_dir",  disp_dir);
 
        pop(xml_tmp);  // Displacement
 
        quark_displacement.xml = xml_tmp.printCurrentContext();
      }
      break;
 
      case 2:
      {
        if (paramtop.count("Displacement") != 0)
          quark_displacement = readXMLGroup(paramtop, "Displacement", "DisplacementType");
        else
          quark_displacement = QuarkDisplacementEnv::nullXMLGroup();
      }
      break;
 
      default:
        QDPIO::cerr << __func__ << ": parameter version " << version 
                    << " unsupported." << std::endl;
        QDP_abort(1);
      }
 
      read(paramtop, "j_decay", j_decay);
      read(paramtop, "t_srce", t_srce);
 
      if (paramtop.count("LinkSmearing") != 0)
        link_smearing = readXMLGroup(paramtop, "LinkSmearing", "LinkSmearingType");
      else
        link_smearing = LinkSmearingEnv::nullXMLGroup();
    }
 
 
    // Writer
    void Params::writeXML(XMLWriter& xml, const std::string& path) const
    {
      push(xml, path);
 
      int version = 2;
      write(xml, "version", version);
 
      write(xml, "SourceType", PointQuarkSourceConstEnv::name);
      write(xml, "j_decay", j_decay);
      write(xml, "t_srce", t_srce);
      xml << link_smearing.xml;
      xml << quark_displacement.xml;
      pop(xml);
    }
 
 
 
    //! Construct the source
    template<>
    LatticePropagator
    SourceConst<LatticePropagator>::operator()(const multi1d<LatticeColorMatrix>& u) const
    {
      QDPIO::cout << "Point source" << std::endl;
 
      // Create the quark source
      LatticePropagator quark_source;
 
      try
      {
        //
        // Smear the gauge field if needed
        //
        multi1d<LatticeColorMatrix> u_smr = u;
        {
          std::istringstream  xml_l(params.link_smearing.xml);
          XMLReader  linktop(xml_l);
          QDPIO::cout << "Link smearing type = " << params.link_smearing.id << std::endl;
        
          Handle< LinkSmearing >
            linkSmearing(TheLinkSmearingFactory::Instance().createObject(params.link_smearing.id,
                                                                         linktop,
                                                                         params.link_smearing.path));
          (*linkSmearing)(u_smr);
        }
 
        //
        // Create the quark displacement object
        //
        std::istringstream  xml_d(params.quark_displacement.xml);
        XMLReader  displacetop(xml_d);
        
        Handle< QuarkDisplacement<LatticePropagator> >
          quarkDisplacement(ThePropDisplacementFactory::Instance().createObject(params.quark_displacement.id,
                                                                                displacetop,
                                                                                params.quark_displacement.path));
 
        for(int color_source = 0; color_source < Nc; ++color_source)
        {
          QDPIO::cout << "color = " << color_source << std::endl; 
 
          LatticeColorVector src_color_vec = zero;
 
          // Make a point source at coordinates t_source
          srcfil(src_color_vec, params.t_srce, color_source);
          
          for(int spin_source = 0; spin_source < Ns; ++spin_source)
          {
            QDPIO::cout << "spin = " << spin_source << std::endl; 
 
            // Insert a ColorVector into spin index spin_source
            // This only overwrites sections, so need to initialize first
            LatticeFermion chi = zero;
            
            CvToFerm(src_color_vec, chi, spin_source);
          
            /*
             *  Move the source to the appropriate components
             *  of quark source.
             */
            FermToProp(chi, quark_source, color_source, spin_source);
          }
        }
 
        // displace the point source first, then smear
        // displacement has to be taken along negative direction.
        (*quarkDisplacement)(quark_source, u_smr, MINUS);
 
      }
      catch(const std::string& e) 
      {
        QDPIO::cerr << name << ": Caught Exception in source construction: " << e << std::endl;
        QDP_abort(1);
      }
 
      return quark_source;
    }
 
 
 
    //! Construct the source
    template<>
    LatticeStaggeredPropagator
    SourceConst<LatticeStaggeredPropagator>::operator()(const multi1d<LatticeColorMatrix>& u) const
    {
      QDPIO::cout << "Point source" << std::endl;
 
      // Create the quark source
      LatticeStaggeredPropagator quark_source;
 
      try
      {
        //
        // Smear the gauge field if needed
        //
        multi1d<LatticeColorMatrix> u_smr = u;
        {
          std::istringstream  xml_l(params.link_smearing.xml);
          XMLReader  linktop(xml_l);
          QDPIO::cout << "Link smearing type = " << params.link_smearing.id << std::endl;
        
          Handle< LinkSmearing >
            linkSmearing(TheLinkSmearingFactory::Instance().createObject(params.link_smearing.id,
                                                                         linktop,
                                                                         params.link_smearing.path));
          (*linkSmearing)(u_smr);
        }
 
        //
        // Create the quark displacement object
        //
        std::istringstream  xml_d(params.quark_displacement.xml);
        XMLReader  displacetop(xml_d);
        
        Handle< QuarkDisplacement<LatticeStaggeredPropagator> >
          quarkDisplacement(TheStagPropDisplacementFactory::Instance().createObject(params.quark_displacement.id,
                                                                                    displacetop,
                                                                                    params.quark_displacement.path));
 
        for(int color_source = 0; color_source < Nc; ++color_source)
        {
          QDPIO::cout << "color = " << color_source << std::endl; 
 
          LatticeColorVector src_color_vec = zero;
 
          // Make a point source at coordinates t_source
          srcfil(src_color_vec, params.t_srce, color_source);
          
          // Insert a ColorVector into spin index spin_source
          // This only overwrites sections, so need to initialize first
          LatticeStaggeredFermion chi = zero;
            
          CvToFerm(src_color_vec, chi);
          
          /*
           *  Move the source to the appropriate components
           *  of quark source.
           */
          FermToProp(chi, quark_source, color_source);
        }
 
        // displace the point source first, then smear
        // displacement has to be taken along negative direction.
        (*quarkDisplacement)(quark_source, u_smr, MINUS);
 
      }
      catch(const std::string& e) 
      {
        QDPIO::cerr << name << ": Caught Exception in source construction: " << e << std::endl;
        QDP_abort(1);
      }
 
      return quark_source;
    }
 
  }
 
}