lemon/lp_skeleton.cc
author Peter Kovacs <kpeter@inf.elte.hu>
Tue, 15 Mar 2011 19:32:21 +0100
changeset 936 ddd3c0d3d9bf
parent 746 e4554cd6b2bf
child 1063 1782aa72495a
permissions -rw-r--r--
Implement the scaling Price Refinement heuristic in CostScaling (#417)
instead of Early Termination.

These two heuristics are similar, but the newer one is faster
and not only makes it possible to skip some epsilon phases, but
it can improve the performance of the other phases, as well.
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/* -*- mode: C++; indent-tabs-mode: nil; -*-
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 *
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 * This file is a part of LEMON, a generic C++ optimization library.
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 *
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 * Copyright (C) 2003-2010
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 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
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 * (Egervary Research Group on Combinatorial Optimization, EGRES).
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 *
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 * Permission to use, modify and distribute this software is granted
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 * provided that this copyright notice appears in all copies. For
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 * precise terms see the accompanying LICENSE file.
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 *
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 * This software is provided "AS IS" with no warranty of any kind,
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 * express or implied, and with no claim as to its suitability for any
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 * purpose.
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 *
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 */
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#include <lemon/lp_skeleton.h>
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///\file
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///\brief A skeleton file to implement LP solver interfaces
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namespace lemon {
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  int SkeletonSolverBase::_addCol()
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  {
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    return ++col_num;
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  }
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  int SkeletonSolverBase::_addRow()
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  {
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    return ++row_num;
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  }
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  int SkeletonSolverBase::_addRow(Value, ExprIterator, ExprIterator, Value)
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  {
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    return ++row_num;
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  }
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  void SkeletonSolverBase::_eraseCol(int) {}
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  void SkeletonSolverBase::_eraseRow(int) {}
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  void SkeletonSolverBase::_getColName(int, std::string &) const {}
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  void SkeletonSolverBase::_setColName(int, const std::string &) {}
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  int SkeletonSolverBase::_colByName(const std::string&) const { return -1; }
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  void SkeletonSolverBase::_getRowName(int, std::string &) const {}
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  void SkeletonSolverBase::_setRowName(int, const std::string &) {}
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  int SkeletonSolverBase::_rowByName(const std::string&) const { return -1; }
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  void SkeletonSolverBase::_setRowCoeffs(int, ExprIterator, ExprIterator) {}
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  void SkeletonSolverBase::_getRowCoeffs(int, InsertIterator) const {}
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  void SkeletonSolverBase::_setColCoeffs(int, ExprIterator, ExprIterator) {}
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  void SkeletonSolverBase::_getColCoeffs(int, InsertIterator) const {}
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  void SkeletonSolverBase::_setCoeff(int, int, Value) {}
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  SkeletonSolverBase::Value SkeletonSolverBase::_getCoeff(int, int) const
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  { return 0; }
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  void SkeletonSolverBase::_setColLowerBound(int, Value) {}
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  SkeletonSolverBase::Value SkeletonSolverBase::_getColLowerBound(int) const
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  {  return 0; }
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  void SkeletonSolverBase::_setColUpperBound(int, Value) {}
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  SkeletonSolverBase::Value SkeletonSolverBase::_getColUpperBound(int) const
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  {  return 0; }
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  void SkeletonSolverBase::_setRowLowerBound(int, Value) {}
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  SkeletonSolverBase::Value SkeletonSolverBase::_getRowLowerBound(int) const
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  {  return 0; }
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  void SkeletonSolverBase::_setRowUpperBound(int, Value) {}
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  SkeletonSolverBase::Value SkeletonSolverBase::_getRowUpperBound(int) const
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  {  return 0; }
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  void SkeletonSolverBase::_setObjCoeffs(ExprIterator, ExprIterator) {}
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  void SkeletonSolverBase::_getObjCoeffs(InsertIterator) const {};
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  void SkeletonSolverBase::_setObjCoeff(int, Value) {}
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  SkeletonSolverBase::Value SkeletonSolverBase::_getObjCoeff(int) const
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  {  return 0; }
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  void SkeletonSolverBase::_setSense(Sense) {}
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  SkeletonSolverBase::Sense SkeletonSolverBase::_getSense() const
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  { return MIN; }
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  void SkeletonSolverBase::_clear() {
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    row_num = col_num = 0;
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  }
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  void SkeletonSolverBase::_messageLevel(MessageLevel) {}
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  LpSkeleton::SolveExitStatus LpSkeleton::_solve() { return SOLVED; }
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  LpSkeleton::Value LpSkeleton::_getPrimal(int) const { return 0; }
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  LpSkeleton::Value LpSkeleton::_getDual(int) const { return 0; }
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  LpSkeleton::Value LpSkeleton::_getPrimalValue() const { return 0; }
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  LpSkeleton::Value LpSkeleton::_getPrimalRay(int) const { return 0; }
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  LpSkeleton::Value LpSkeleton::_getDualRay(int) const { return 0; }
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  LpSkeleton::ProblemType LpSkeleton::_getPrimalType() const
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  { return UNDEFINED; }
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  LpSkeleton::ProblemType LpSkeleton::_getDualType() const
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  { return UNDEFINED; }
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  LpSkeleton::VarStatus LpSkeleton::_getColStatus(int) const
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  { return BASIC; }
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  LpSkeleton::VarStatus LpSkeleton::_getRowStatus(int) const
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  { return BASIC; }
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  LpSkeleton* LpSkeleton::newSolver() const
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  { return static_cast<LpSkeleton*>(0); }
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  LpSkeleton* LpSkeleton::cloneSolver() const
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  { return static_cast<LpSkeleton*>(0); }
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  const char* LpSkeleton::_solverName() const { return "LpSkeleton"; }
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  MipSkeleton::SolveExitStatus MipSkeleton::_solve()
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  { return SOLVED; }
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  MipSkeleton::Value MipSkeleton::_getSol(int) const { return 0; }
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  MipSkeleton::Value MipSkeleton::_getSolValue() const { return 0; }
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  MipSkeleton::ProblemType MipSkeleton::_getType() const
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  { return UNDEFINED; }
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  MipSkeleton* MipSkeleton::newSolver() const
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  { return static_cast<MipSkeleton*>(0); }
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  MipSkeleton* MipSkeleton::cloneSolver() const
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  { return static_cast<MipSkeleton*>(0); }
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  const char* MipSkeleton::_solverName() const { return "MipSkeleton"; }
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} //namespace lemon
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