llincomb.h

Go to the documentation of this file.

// -*- C++ -*-
 
#ifndef __llincomb_h__
#define __llincomb_h__
 
#include "handle.h"
#include "linearop.h"
 
 
namespace Chroma
{
  //! Linear combination of a Linear Operator
  /*!
   * \ingroup linop
   *
   * This operator does the linear combination  (z1 + z2*B)*psi
   */
  template<typename T, class C>
  class llincomb : public LinearOperator<T>
  {
  public:
    //! Initialize pointer with existing pointer
    /*! Requires that the pointer p is a return value of new */
    llincomb(const LinearOperator<T>* p, const C& add_const_, const C& scale_fact_) : 
      A(p), add_const(add_const_), scale_fact(scale_fact_)  {}
 
    //! Copy pointer (one more owner)
    llincomb(Handle<const LinearOperator<T> > p, const C& add_const_, const C& scale_fact_) : 
      A(p), add_const(add_const_), scale_fact(scale_fact_) {}
 
    //! Destructor
    ~llincomb() {}
 
    //! Subset comes from underlying operator
    inline const Subset& subset() const {return A->subset();}
 
    //! Apply the operator onto a source std::vector
    /*! For this operator, the sign is ignored */
    inline void operator() (T& chi, const T& psi, enum PlusMinus isign) const
      {
        const Subset& sub = A->subset();
        (*A)(chi, psi, isign);
        chi[sub] *= scale_fact;
        chi[sub] += add_const*psi;
      }
 
  private:
    const Handle< const LinearOperator<T> > A;
    const C add_const;
    const C scale_fact;
  };
}
 
 
#endif