Interaction.h

#ifndef CPC_INTERACTION_H
#define CPC_INTERACTION_H
 
/*
* PSCF - Polymer Self-Consistent Field
*
* Copyright 2015 - 2025, The Regents of the University of Minnesota
* Distributed under the terms of the GNU General Public License.
*/
 
#include <util/param/ParamComposite.h>    // base class
#include <util/containers/Matrix.h>       // argument (template)
 
namespace Pscf {
 
   using namespace Util;

   class Interaction : public ParamComposite
   {
 
   public:

      Interaction(bool isCompressible = false);

      virtual ~Interaction();
 
      // Modifiers

      void setNMonomer(int nMonomer);

      virtual void readParameters(std::istream& in);

      void setChi(int i, int j, double chi);
 
      // Accessors

      int nMonomer() const;

      DMatrix<double> const & chi() const;

      double chi(int i, int j) const;

      double zeta() const; 

      bool isCompressible() const; 
 
   private:
 
      // Symmetric matrix of interaction parameters.
      DMatrix<double> chi_;
 
      // Dimensionless compression modulus (a la Helfand)
      double zeta_;
 
      // Number of monomers.
      int nMonomer_;
 
      // Is the model compressible (does it allow a finite zeta value)?
      bool isCompressible_;
 
      // Has the object been initialized via readParameters?
      bool isInitialized_;

      void setChiZero();
 
   };
 
   // Inline functions
 
   /*
   * Return the number of monomer types.
   */
   inline int Interaction::nMonomer() const
   {  return nMonomer_; }
 
   /*
   * Return the entire chi matrix by const reference.
   */
   inline DMatrix<double> const &  Interaction::chi() const
   {  return chi_; }
 
   /*
   * Return one element of the chi matrix.
   */
   inline double Interaction::chi(int i, int j) const
   {  return chi_(i, j); }
 
   /*
   * Return the dimensionless compression modulus, zeta.
   */
   inline double Interaction::zeta() const
   {  return zeta_; }
 
   /*
   * Is this model compressible?
   */
   inline bool Interaction::isCompressible() const
   {  return isCompressible_; }
 
} // namespace Pscf
#endif