// Copyright (C) 2004, 2008 International Business Machines and others.
// All Rights Reserved.
// This code is published under the Eclipse Public License.
//
// $Id$
//
// Authors:  Carl Laird, Andreas Waechter     IBM    2004-08-13

#ifndef __IPDIAGMATRIX_HPP__
#define __IPDIAGMATRIX_HPP__

#include "IpUtils.hpp"
#include "IpSymMatrix.hpp"

namespace Ipopt
{

  /** Class for diagonal matrices.  The diagonal is stored as a
   *  Vector. */
  class DiagMatrix : public SymMatrix
  {
  public:

    /**@name Constructors / Destructors */
    //@{

    /** Constructor, given the corresponding matrix space. */
    DiagMatrix(const SymMatrixSpace* owner_space);

    /** Destructor */
    ~DiagMatrix();
    //@}

    /** Method for setting the diagonal elements (as a Vector). */
    void SetDiag(const Vector& diag)
    {
      diag_ = &diag;
    }

    /** Method for setting the diagonal elements. */
    SmartPtr<const Vector> GetDiag() const
    {
      return diag_;
    }

  protected:
    /**@name Methods overloaded from matrix */
    //@{
    virtual void MultVectorImpl(Number alpha, const Vector& x,
                                Number beta, Vector& y) const;

    /** Method for determining if all stored numbers are valid (i.e.,
     *  no Inf or Nan). */
    virtual bool HasValidNumbersImpl() const;

    virtual void ComputeRowAMaxImpl(Vector& rows_norms, bool init) const;

    virtual void PrintImpl(const Journalist& jnlst,
                           EJournalLevel level,
                           EJournalCategory category,
                           const std::string& name,
                           Index indent,
                           const std::string& prefix) const;
    //@}

  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. */
    //@{
    /** Default Constructor */
    DiagMatrix();

    /** Copy Constructor */
    DiagMatrix(const DiagMatrix&);

    /** Overloaded Equals Operator */
    void operator=(const DiagMatrix&);
    //@}

    /** Vector storing the diagonal elements */
    SmartPtr<const Vector> diag_;
  };

  /** This is the matrix space for DiagMatrix. */
  class DiagMatrixSpace : public SymMatrixSpace
  {
  public:
    /** @name Constructors / Destructors */
    //@{
    /** Constructor, given the dimension of the matrix. */
    DiagMatrixSpace(Index dim)
        :
        SymMatrixSpace(dim)
    {}

    /** Destructor */
    virtual ~DiagMatrixSpace()
    {}
    //@}

    /** Overloaded MakeNew method for the SymMatrixSpace base class.
     */
    virtual SymMatrix* MakeNewSymMatrix() const
    {
      return MakeNewDiagMatrix();
    }

    /** Method for creating a new matrix of this specific type. */
    DiagMatrix* MakeNewDiagMatrix() const
    {
      return new DiagMatrix(this);
    }

  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. */
    //@{
    /** Default Constructor */
    DiagMatrixSpace();

    /** Copy Constructor */
    DiagMatrixSpace(const DiagMatrixSpace&);

    /** Overloaded Equals Operator */
    void operator=(const DiagMatrixSpace&);
    //@}

  };

} // namespace Ipopt
#endif
