wilson_gaugeact.h

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// -*- C++ -*-
/*! \file
 *  \brief Wilson gauge action
 */
 
#ifndef __wilson_gaugeact_h__
#define __wilson_gaugeact_h__
 
#include "gaugeact.h"
#include "gaugebc.h"
#include "actions/gauge/gaugeacts/plaq_gaugeact.h"
#include "actions/gauge/gaugeacts/wilson_gaugeact_params.h"
 
namespace Chroma
{
 
  /*! @ingroup gaugeacts */
  namespace WilsonGaugeActEnv 
  { 
    extern const std::string name;
    bool registerAll();
  }
 
  //! Wilson gauge action
  /*! \ingroup gaugeacts
   *
   * The standard Wilson gauge action
   */
 
  class WilsonGaugeAct : public LinearGaugeAction
  {
  public:
    //! General CreateGaugeState<P,Q>
    WilsonGaugeAct(Handle< CreateGaugeState<P,Q> > cgs_, 
                   const Real& beta)
      {param.beta = beta; init(cgs_);}
 
    //! General CreateGaugeState<P,Q>
    WilsonGaugeAct(Handle< CreateGaugeState<P,Q> > cgs_, 
                   const Real& beta,
                   const AnisoParam_t& aniso)
      {param.beta = beta; param.aniso = aniso; init(cgs_);}
 
    //! Read beta from a param struct
    WilsonGaugeAct(Handle< CreateGaugeState<P,Q> > cgs_, 
                   const WilsonGaugeActParams& p) :
      param(p) {init(cgs_);}
 
    //! Is anisotropy used?
    bool anisoP() const {return param.aniso.anisoP;}
 
    //! Anisotropy factor
    const Real anisoFactor() const {return param.aniso.xi_0;}
 
    //! Anisotropic direction
    int tDir() const {return param.aniso.t_dir;}
 
    //! Return the set on which the gauge action is defined
    /*! Defined on the even-off (red/black) set */
    const Set& getSet() const {return rb;}
 
    //! Compute staple
    /*! Default version. Derived class should override this if needed. */
    void staple(LatticeColorMatrix& result,
                const Handle< GaugeState<P,Q> >& state,
                int mu, int cb) const
    {
      plaq->staple(result,state,mu,cb);
    }
 
    //! Compute dS/dU
    void deriv(multi1d<LatticeColorMatrix>& result,
               const Handle< GaugeState<P,Q> >& state) const
    {
      plaq->deriv(result,state);
    }
 
    //! Compute the actions
    Double S(const Handle< GaugeState<P,Q> >& state) const
    {
      return plaq->S(state);
    }
 
    //! Destructor is automatic
    ~WilsonGaugeAct() {}
 
    // Accessors -- non mutable members.
    const Real getBeta(void) const {return param.beta;}
 
    //! Produce a gauge create state object
    const CreateGaugeState<P,Q>& getCreateState() const {return plaq->getCreateState();}
 
  protected:
    //! Private initializer
    void init(Handle< CreateGaugeState<P,Q> > cgs);
 
    //! Partial constructor
    WilsonGaugeAct() {}
    //! Hide assignment
    void operator=(const WilsonGaugeAct& a) {}
 
  private:
    Handle<PlaqGaugeAct> plaq;  // Hold a plaquette gaugeact
    WilsonGaugeActParams param; // parameters
  };
 
} // end namespace Chroma
 
 
#endif