// Copyright (C) 2004, 2006 International Business Machines and others.
// All Rights Reserved.
// This code is published under the Eclipse Public License.
//
// Authors:  Carl Laird, Andreas Waechter              IBM    2004-09-23

#ifndef __IPEQMULTCALCULATOR_HPP__
#define __IPEQMULTCALCULATOR_HPP__

#include "IpUtils.hpp"
#include "IpAlgStrategy.hpp"

namespace Ipopt
{
/** Base Class for objects that compute estimates for the equality
 *  constraint multipliers y_c and y_d.
 *
 *  For example, this is the base class for objects for computing
 *  least square multipliers or coordinate multipliers.
 */
class EqMultiplierCalculator: public AlgorithmStrategyObject
{
public:
   /**@name Constructors/Destructors */
   ///@{
   /** Default Constructor. */
   EqMultiplierCalculator()
   { }
   /** Destructor */
   virtual ~EqMultiplierCalculator()
   { }
   ///@}

   /** overloaded from AlgorithmStrategyObject */
   virtual bool InitializeImpl(
      const OptionsList& options,
      const std::string& prefix
   ) = 0;

   /** This method computes the estimates for y_c and y_d at the
    *  current point.
    *
    *  If the estimates cannot be computed (e.g. some linear system
    *  is singular), the return value of this method is false.
    */
   virtual bool CalculateMultipliers(
      Vector& y_c,
      Vector& y_d
   ) = 0;

private:
   /**@name Default Compiler Generated Methods
    * (Hidden to avoid implicit creation/calling).
    *
    * These methods are not implemented and
    * we do not want the compiler to implement
    * them for us, so we declare them private
    * and do not define them. This ensures that
    * they will not be implicitly created/called.
    */
   ///@{
   /** Copy Constructor */
   EqMultiplierCalculator(
      const EqMultiplierCalculator&
   );

   /** Default Assignment Operator */
   void operator=(
      const EqMultiplierCalculator&
   );
   ///@}
};

} // namespace Ipopt

#endif
