dsvector.h

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/*                  This file is part of the class library                   */
/*       SoPlex --- the Sequential object-oriented simPlex.                  */
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/*    Copyright (C) 1996-2012 Konrad-Zuse-Zentrum                            */
/*                            fuer Informationstechnik Berlin                */
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/**@file  dsvector.h
 * @brief Dynamic sparse vectors.
 */
#ifndef _DSVECTOR_H_
#define _DSVECTOR_H_

#include <assert.h>

#include "spxdefines.h"
#include "svector.h"
#include "ssvector.h"

namespace soplex
{
/**@brief   Dynamic sparse vectors.
   @ingroup Algebra

   Class DSVector implements dynamic sparse vectors, i.e. #SVector%s
   with an automatic memory management. This allows the user to freely add()
   as many nonzeros to a DSVector as desired, without any precautions.
   For saving memory method setMax() allows to reduce memory consumption to
   the amount really required.

   @todo Both DSVector and SVector have a member variable that points to
         allocated memory. This does not seem to make too much sense.
         Why doesn't DSVector use the element of its base class?
 */
class DSVector : public SVector
{
   friend class SLinSolver;

private:

   //-----------------------------------
   /**@name Data */
   //@{
   Element* theelem;       ///< here is where the memory is
   //@}

   //-----------------------------------
   /**@name Private memory helpers */
   //@{
   /// allocate memory for \p n nonzeros. 
   void allocMem(int n);
   /// make sure there is room for \p n new nonzeros.
   void makeMem(int n)
   {
      if (max() - size() < ++n)
         setMax(size() + n);
   }
   //@}

public:

   //-----------------------------------
   /**@name Construction / destruction */
   //@{
   /// default constructor.
   /** Creates a DSVector ready to hold \p n nonzeros. However, the memory is
    *  automatically enlarged, if more nonzeros are added to the DSVector.
    */
   explicit DSVector(int n = 8);

   /// destructor.
   ~DSVector();
   /// copy constructor from vector.
   explicit DSVector(const Vector& vec);
   /// copy constructor from sparse vector.
   explicit DSVector(const SVector& old);
   /// copy constructor from semi sparse vector.
   explicit DSVector(const SSVector& old);
   /// copy constructor from DSVector.
   DSVector(const DSVector& old);

   /// assignment operator from semi sparse vector.
   DSVector& operator=(const SSVector& sv)
   {
      int n = sv.size();
      clear();
      makeMem(n);
      SVector::operator=(sv);
      return *this;
   }
   /// assignment operator from sparse vector.
   DSVector& operator=(const SVector& sv)
   {
      int n = sv.size();
      clear();
      makeMem(n);
      SVector::operator=(sv);
      return *this;
   }
   /// assignment operator.
   DSVector& operator=(const DSVector& sv)
   {
      if (this != &sv)
      {
         int n = sv.size();
         clear();
         makeMem(n);
         SVector::operator=(sv);
      }
      return *this;
   }
   /// assignment operator from vector.
   DSVector& operator=(const Vector& vec);
   //@}

   //-----------------------------------
   /**@name Adding nonzeros */
   //@{
   /// append nonzeros of \p sv.
   void add(const SVector& sv)
   {
      int n = sv.size();
      clear();
      makeMem(n);
      SVector::add(sv);
   }

   /// append one nonzero \p (i,v).
   void add(int i, Real v)
   {
      makeMem(1);
      SVector::add(i, v);
   }

   /// append \p n nonzeros.
   void add(int n, const int i[], const Real v[])
   {
      makeMem(n);
      SVector::add(n, i, v);
   }

   /// reset nonzero memory to >= \p newmax.
   /** This methods resets the memory consumption of the DIdxSet to
    *  \p newmax. However, if \p newmax < size(), it is reset to size()
    *  only.
    */
   void setMax(int newmax = 1);
   //@}

   //-----------------------------------
   /**@name Consistency check */
   //@{
   /// consistency check.
   bool isConsistent() const;
   //@}
};
} // namespace soplex
#endif // _DSVECTOR_H_

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