source: branches/devel/Cbc/src/CbcBranchLotsize.hpp @ 631

// Copyright (C) 2004, International Business Machines
// Corporation and others.  All Rights Reserved.
#ifndef CbcBranchLotsize_H
#define CbcBranchLotsize_H

#include "CbcBranchBase.hpp"

/** Lotsize class */


class CbcLotsize : public CbcObject {

public:

  // Default Constructor 
  CbcLotsize ();

  /* Useful constructor - passed model index.
     Also passed valid values - if range then pairs
  */
  CbcLotsize (CbcModel * model, int iColumn,
              int numberPoints, const double * points, bool range=false);
  
  // Copy constructor 
  CbcLotsize ( const CbcLotsize &);
   
  /// Clone
  virtual CbcObject * clone() const;

  // Assignment operator 
  CbcLotsize & operator=( const CbcLotsize& rhs);

  // Destructor 
  ~CbcLotsize ();
  
  /// Infeasibility - large is 0.5
  virtual double infeasibility(int & preferredWay) const;

  /** Set bounds to contain the current solution.

    More precisely, for the variable associated with this object, take the
    value given in the current solution, force it within the current bounds
    if required, then set the bounds to fix the variable at the integer
    nearest the solution value.
  */
  virtual void feasibleRegion();

  /// Creates a branching object
  virtual CbcBranchingObject * createBranch(int way) ;

  /** \brief Given a valid solution (with reduced costs, etc.),
      return a branching object which would give a new feasible
      point in the good direction.

    The preferred branching object will force the variable to be +/-1 from
    its current value, depending on the reduced cost and objective sense.  If
    movement in the direction which improves the objective is impossible due
    to bounds on the variable, the branching object will move in the other
    direction.  If no movement is possible, the method returns NULL.

    Only the bounds on this variable are considered when determining if the new
    point is feasible.
  */
  virtual CbcBranchingObject * preferredNewFeasible() const;
  
  /** \brief Given a valid solution (with reduced costs, etc.),
      return a branching object which would give a new feasible
      point in a bad direction.

    As for preferredNewFeasible(), but the preferred branching object will
    force movement in a direction that degrades the objective.
  */
  virtual CbcBranchingObject * notPreferredNewFeasible() const ;
  
  /** Reset original upper and lower bound values from the solver.
  
    Handy for updating bounds held in this object after bounds held in the
    solver have been tightened.
   */
  virtual void resetBounds(const OsiSolverInterface * solver);

  /** Finds range of interest so value is feasible in range range_ or infeasible 
      between hi[range_] and lo[range_+1].  Returns true if feasible.
  */
  bool findRange(double value) const;
  
  /** Returns floor and ceiling
  */
  virtual void floorCeiling(double & floorLotsize, double & ceilingLotsize, double value,
                            double tolerance) const;
  
  /// Model column number
  inline int modelSequence() const
  {return columnNumber_;};

  /** Column number if single column object -1 otherwise,
      so returns >= 0
      Used by heuristics
  */
  virtual int columnNumber() const;
  /// Original bounds
  inline double originalLowerBound() const
  { return bound_[0];};
  inline double originalUpperBound() const
  { return bound_[rangeType_*numberRanges_-1];};
  /// Type - 1 points, 2 ranges
  inline int rangeType() const
  { return rangeType_;};
  /// Number of points
  inline int numberRanges() const
  { return numberRanges_;};
  /// Ranges
  inline double * bound() const
  { return bound_;};
  /** \brief Return true if object can take part in normal heuristics
  */
  virtual bool canDoHeuristics() const 
  {return false;};

private:
  /// Just for debug (CBC_PRINT defined in CbcBranchLotsize.cpp)
  void printLotsize(double value,bool condition,int type) const;

private:
  /// data

  /// Column number in model
  int columnNumber_;
  /// Type - 1 points, 2 ranges
  int rangeType_;
  /// Number of points
  int numberRanges_;
  // largest gap
  double largestGap_;
  /// Ranges
  double * bound_;
  /// Current range
  mutable int range_;
};


/** Lotsize branching object

  This object can specify a two-way branch on an integer variable. For each
  arm of the branch, the upper and lower bounds on the variable can be
  independently specified.
  
  Variable_ holds the index of the integer variable in the integerVariable_
  array of the model.
*/

class CbcLotsizeBranchingObject : public CbcBranchingObject {

public:

  /// Default constructor 
  CbcLotsizeBranchingObject ();

  /** Create a lotsize floor/ceiling branch object

    Specifies a simple two-way branch. Let \p value = x*. One arm of the
    branch will be is lb <= x <= valid range below(x*), the other valid range above(x*) <= x <= ub.
    Specify way = -1 to set the object state to perform the down arm first,
    way = 1 for the up arm.
  */
  CbcLotsizeBranchingObject (CbcModel *model, int variable,
                             int way , double value,const CbcLotsize * lotsize) ;
  
  /** Create a degenerate branch object

    Specifies a `one-way branch'. Calling branch() for this object will
    always result in lowerValue <= x <= upperValue. Used to fix in valid range
  */

  CbcLotsizeBranchingObject (CbcModel *model, int variable, int way,
                             double lowerValue, double upperValue) ;
  
  /// Copy constructor 
  CbcLotsizeBranchingObject ( const CbcLotsizeBranchingObject &);
   
  /// Assignment operator 
  CbcLotsizeBranchingObject & operator= (const CbcLotsizeBranchingObject& rhs);

  /// Clone
  virtual CbcBranchingObject * clone() const;

  /// Destructor 
  virtual ~CbcLotsizeBranchingObject ();
  
  /** \brief Sets the bounds for the variable according to the current arm
             of the branch and advances the object state to the next arm.
  */
  virtual double branch();

  /** \brief Print something about branch - only if log level high
  */
  virtual void print();

protected:
  /// Lower [0] and upper [1] bounds for the down arm (way_ = -1)
  double down_[2];
  /// Lower [0] and upper [1] bounds for the up arm (way_ = 1)
  double up_[2];
};


#endif