diff --git a/lemon/soplex.cc b/lemon/soplex.cc
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+++ b/lemon/soplex.cc
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+/* -*- mode: C++; indent-tabs-mode: nil; -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library.
+ *
+ * Copyright (C) 2003-2008
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#include <iostream>
+#include <lemon/soplex.h>
+
+#include <soplex.h>
+#include <spxout.h>
+
+
+///\file
+///\brief Implementation of the LEMON-SOPLEX lp solver interface.
+namespace lemon {
+
+  SoplexLp::SoplexLp() {
+    soplex = new soplex::SoPlex;
+    messageLevel(MESSAGE_NOTHING);
+  }
+
+  SoplexLp::~SoplexLp() {
+    delete soplex;
+  }
+
+  SoplexLp::SoplexLp(const SoplexLp& lp) {
+    rows = lp.rows;
+    cols = lp.cols;
+
+    soplex = new soplex::SoPlex;
+    (*static_cast<soplex::SPxLP*>(soplex)) = *(lp.soplex);
+
+    _col_names = lp._col_names;
+    _col_names_ref = lp._col_names_ref;
+
+    _row_names = lp._row_names;
+    _row_names_ref = lp._row_names_ref;
+
+    messageLevel(MESSAGE_NOTHING);
+  }
+
+  void SoplexLp::_clear_temporals() {
+    _primal_values.clear();
+    _dual_values.clear();
+  }
+
+  SoplexLp* SoplexLp::newSolver() const {
+    SoplexLp* newlp = new SoplexLp();
+    return newlp;
+  }
+
+  SoplexLp* SoplexLp::cloneSolver() const {
+    SoplexLp* newlp = new SoplexLp(*this);
+    return newlp;
+  }
+
+  const char* SoplexLp::_solverName() const { return "SoplexLp"; }
+
+  int SoplexLp::_addCol() {
+    soplex::LPCol c;
+    c.setLower(-soplex::infinity);
+    c.setUpper(soplex::infinity);
+    soplex->addCol(c);
+
+    _col_names.push_back(std::string());
+
+    return soplex->nCols() - 1;
+  }
+
+  int SoplexLp::_addRow() {
+    soplex::LPRow r;
+    r.setLhs(-soplex::infinity);
+    r.setRhs(soplex::infinity);
+    soplex->addRow(r);
+
+    _row_names.push_back(std::string());
+
+    return soplex->nRows() - 1;
+  }
+
+  int SoplexLp::_addRow(Value l, ExprIterator b, ExprIterator e, Value u) {
+    soplex::DSVector v;
+    for (ExprIterator it = b; it != e; ++it) {
+      v.add(it->first, it->second);
+    }
+    soplex::LPRow r(l, v, u);
+    soplex->addRow(r);
+
+    _row_names.push_back(std::string());
+
+    return soplex->nRows() - 1;
+  }
+
+
+  void SoplexLp::_eraseCol(int i) {
+    soplex->removeCol(i);
+    _col_names_ref.erase(_col_names[i]);
+    _col_names[i] = _col_names.back();
+    _col_names_ref[_col_names.back()] = i;
+    _col_names.pop_back();
+  }
+
+  void SoplexLp::_eraseRow(int i) {
+    soplex->removeRow(i);
+    _row_names_ref.erase(_row_names[i]);
+    _row_names[i] = _row_names.back();
+    _row_names_ref[_row_names.back()] = i;
+    _row_names.pop_back();
+  }
+
+  void SoplexLp::_eraseColId(int i) {
+    cols.eraseIndex(i);
+    cols.relocateIndex(i, cols.maxIndex());
+  }
+  void SoplexLp::_eraseRowId(int i) {
+    rows.eraseIndex(i);
+    rows.relocateIndex(i, rows.maxIndex());
+  }
+
+  void SoplexLp::_getColName(int c, std::string &name) const {
+    name = _col_names[c];
+  }
+
+  void SoplexLp::_setColName(int c, const std::string &name) {
+    _col_names_ref.erase(_col_names[c]);
+    _col_names[c] = name;
+    if (!name.empty()) {
+      _col_names_ref.insert(std::make_pair(name, c));
+    }
+  }
+
+  int SoplexLp::_colByName(const std::string& name) const {
+    std::map<std::string, int>::const_iterator it =
+      _col_names_ref.find(name);
+    if (it != _col_names_ref.end()) {
+      return it->second;
+    } else {
+      return -1;
+    }
+  }
+
+  void SoplexLp::_getRowName(int r, std::string &name) const {
+    name = _row_names[r];
+  }
+
+  void SoplexLp::_setRowName(int r, const std::string &name) {
+    _row_names_ref.erase(_row_names[r]);
+    _row_names[r] = name;
+    if (!name.empty()) {
+      _row_names_ref.insert(std::make_pair(name, r));
+    }
+  }
+
+  int SoplexLp::_rowByName(const std::string& name) const {
+    std::map<std::string, int>::const_iterator it =
+      _row_names_ref.find(name);
+    if (it != _row_names_ref.end()) {
+      return it->second;
+    } else {
+      return -1;
+    }
+  }
+
+
+  void SoplexLp::_setRowCoeffs(int i, ExprIterator b, ExprIterator e) {
+    for (int j = 0; j < soplex->nCols(); ++j) {
+      soplex->changeElement(i, j, 0.0);
+    }
+    for(ExprIterator it = b; it != e; ++it) {
+      soplex->changeElement(i, it->first, it->second);
+    }
+  }
+
+  void SoplexLp::_getRowCoeffs(int i, InsertIterator b) const {
+    const soplex::SVector& vec = soplex->rowVector(i);
+    for (int k = 0; k < vec.size(); ++k) {
+      *b = std::make_pair(vec.index(k), vec.value(k));
+      ++b;
+    }
+  }
+
+  void SoplexLp::_setColCoeffs(int j, ExprIterator b, ExprIterator e) {
+    for (int i = 0; i < soplex->nRows(); ++i) {
+      soplex->changeElement(i, j, 0.0);
+    }
+    for(ExprIterator it = b; it != e; ++it) {
+      soplex->changeElement(it->first, j, it->second);
+    }
+  }
+
+  void SoplexLp::_getColCoeffs(int i, InsertIterator b) const {
+    const soplex::SVector& vec = soplex->colVector(i);
+    for (int k = 0; k < vec.size(); ++k) {
+      *b = std::make_pair(vec.index(k), vec.value(k));
+      ++b;
+    }
+  }
+
+  void SoplexLp::_setCoeff(int i, int j, Value value) {
+    soplex->changeElement(i, j, value);
+  }
+
+  SoplexLp::Value SoplexLp::_getCoeff(int i, int j) const {
+    return soplex->rowVector(i)[j];
+  }
+
+  void SoplexLp::_setColLowerBound(int i, Value value) {
+    LEMON_ASSERT(value != INF, "Invalid bound");
+    soplex->changeLower(i, value != -INF ? value : -soplex::infinity);
+  }
+
+  SoplexLp::Value SoplexLp::_getColLowerBound(int i) const {
+    double value = soplex->lower(i);
+    return value != -soplex::infinity ? value : -INF;
+  }
+
+  void SoplexLp::_setColUpperBound(int i, Value value) {
+    LEMON_ASSERT(value != -INF, "Invalid bound");
+    soplex->changeUpper(i, value != INF ? value : soplex::infinity);
+  }
+
+  SoplexLp::Value SoplexLp::_getColUpperBound(int i) const {
+    double value = soplex->upper(i);
+    return value != soplex::infinity ? value : INF;
+  }
+
+  void SoplexLp::_setRowLowerBound(int i, Value lb) {
+    LEMON_ASSERT(lb != INF, "Invalid bound");
+    soplex->changeRange(i, lb != -INF ? lb : -soplex::infinity, soplex->rhs(i));
+  }
+
+  SoplexLp::Value SoplexLp::_getRowLowerBound(int i) const {
+    double res = soplex->lhs(i);
+    return res == -soplex::infinity ? -INF : res;
+  }
+
+  void SoplexLp::_setRowUpperBound(int i, Value ub) {
+    LEMON_ASSERT(ub != -INF, "Invalid bound");
+    soplex->changeRange(i, soplex->lhs(i), ub != INF ? ub : soplex::infinity);
+  }
+
+  SoplexLp::Value SoplexLp::_getRowUpperBound(int i) const {
+    double res = soplex->rhs(i);
+    return res == soplex::infinity ? INF : res;
+  }
+
+  void SoplexLp::_setObjCoeffs(ExprIterator b, ExprIterator e) {
+    for (int j = 0; j < soplex->nCols(); ++j) {
+      soplex->changeObj(j, 0.0);
+    }
+    for (ExprIterator it = b; it != e; ++it) {
+      soplex->changeObj(it->first, it->second);
+    }
+  }
+
+  void SoplexLp::_getObjCoeffs(InsertIterator b) const {
+    for (int j = 0; j < soplex->nCols(); ++j) {
+      Value coef = soplex->obj(j);
+      if (coef != 0.0) {
+        *b = std::make_pair(j, coef);
+        ++b;
+      }
+    }
+  }
+
+  void SoplexLp::_setObjCoeff(int i, Value obj_coef) {
+    soplex->changeObj(i, obj_coef);
+  }
+
+  SoplexLp::Value SoplexLp::_getObjCoeff(int i) const {
+    return soplex->obj(i);
+  }
+
+  SoplexLp::SolveExitStatus SoplexLp::_solve() {
+
+    _clear_temporals();
+    
+    _applyMessageLevel();
+
+    soplex::SPxSolver::Status status = soplex->solve();
+
+    switch (status) {
+    case soplex::SPxSolver::OPTIMAL:
+    case soplex::SPxSolver::INFEASIBLE:
+    case soplex::SPxSolver::UNBOUNDED:
+      return SOLVED;
+    default:
+      return UNSOLVED;
+    }
+  }
+
+  SoplexLp::Value SoplexLp::_getPrimal(int i) const {
+    if (_primal_values.empty()) {
+      _primal_values.resize(soplex->nCols());
+      soplex::Vector pv(_primal_values.size(), &_primal_values.front());
+      soplex->getPrimal(pv);
+    }
+    return _primal_values[i];
+  }
+
+  SoplexLp::Value SoplexLp::_getDual(int i) const {
+    if (_dual_values.empty()) {
+      _dual_values.resize(soplex->nRows());
+      soplex::Vector dv(_dual_values.size(), &_dual_values.front());
+      soplex->getDual(dv);
+    }
+    return _dual_values[i];
+  }
+
+  SoplexLp::Value SoplexLp::_getPrimalValue() const {
+    return soplex->objValue();
+  }
+
+  SoplexLp::VarStatus SoplexLp::_getColStatus(int i) const {
+    switch (soplex->getBasisColStatus(i)) {
+    case soplex::SPxSolver::BASIC:
+      return BASIC;
+    case soplex::SPxSolver::ON_UPPER:
+      return UPPER;
+    case soplex::SPxSolver::ON_LOWER:
+      return LOWER;
+    case soplex::SPxSolver::FIXED:
+      return FIXED;
+    case soplex::SPxSolver::ZERO:
+      return FREE;
+    default:
+      LEMON_ASSERT(false, "Wrong column status");
+      return VarStatus();
+    }
+  }
+
+  SoplexLp::VarStatus SoplexLp::_getRowStatus(int i) const {
+    switch (soplex->getBasisRowStatus(i)) {
+    case soplex::SPxSolver::BASIC:
+      return BASIC;
+    case soplex::SPxSolver::ON_UPPER:
+      return UPPER;
+    case soplex::SPxSolver::ON_LOWER:
+      return LOWER;
+    case soplex::SPxSolver::FIXED:
+      return FIXED;
+    case soplex::SPxSolver::ZERO:
+      return FREE;
+    default:
+      LEMON_ASSERT(false, "Wrong row status");
+      return VarStatus();
+    }
+  }
+
+  SoplexLp::Value SoplexLp::_getPrimalRay(int i) const {
+    if (_primal_ray.empty()) {
+      _primal_ray.resize(soplex->nCols());
+      soplex::Vector pv(_primal_ray.size(), &_primal_ray.front());
+      soplex->getDualfarkas(pv);
+    }
+    return _primal_ray[i];
+  }
+
+  SoplexLp::Value SoplexLp::_getDualRay(int i) const {
+    if (_dual_ray.empty()) {
+      _dual_ray.resize(soplex->nRows());
+      soplex::Vector dv(_dual_ray.size(), &_dual_ray.front());
+      soplex->getDualfarkas(dv);
+    }
+    return _dual_ray[i];
+  }
+
+  SoplexLp::ProblemType SoplexLp::_getPrimalType() const {
+    switch (soplex->status()) {
+    case soplex::SPxSolver::OPTIMAL:
+      return OPTIMAL;
+    case soplex::SPxSolver::UNBOUNDED:
+      return UNBOUNDED;
+    case soplex::SPxSolver::INFEASIBLE:
+      return INFEASIBLE;
+    default:
+      return UNDEFINED;
+    }
+  }
+
+  SoplexLp::ProblemType SoplexLp::_getDualType() const {
+    switch (soplex->status()) {
+    case soplex::SPxSolver::OPTIMAL:
+      return OPTIMAL;
+    case soplex::SPxSolver::UNBOUNDED:
+      return UNBOUNDED;
+    case soplex::SPxSolver::INFEASIBLE:
+      return INFEASIBLE;
+    default:
+      return UNDEFINED;
+    }
+  }
+
+  void SoplexLp::_setSense(Sense sense) {
+    switch (sense) {
+    case MIN:
+      soplex->changeSense(soplex::SPxSolver::MINIMIZE);
+      break;
+    case MAX:
+      soplex->changeSense(soplex::SPxSolver::MAXIMIZE);
+    }
+  }
+
+  SoplexLp::Sense SoplexLp::_getSense() const {
+    switch (soplex->spxSense()) {
+    case soplex::SPxSolver::MAXIMIZE:
+      return MAX;
+    case soplex::SPxSolver::MINIMIZE:
+      return MIN;
+    default:
+      LEMON_ASSERT(false, "Wrong sense.");
+      return SoplexLp::Sense();
+    }
+  }
+
+  void SoplexLp::_clear() {
+    soplex->clear();
+    _col_names.clear();
+    _col_names_ref.clear();
+    _row_names.clear();
+    _row_names_ref.clear();
+    cols.clear();
+    rows.clear();
+    _clear_temporals();
+  }
+
+  void SoplexLp::_messageLevel(MessageLevel level) {
+    switch (level) {
+    case MESSAGE_NOTHING:
+      _message_level = -1;
+      break;
+    case MESSAGE_ERROR:
+      _message_level = soplex::SPxOut::ERROR;
+      break;
+    case MESSAGE_WARNING:
+      _message_level = soplex::SPxOut::WARNING;
+      break;
+    case MESSAGE_NORMAL:
+      _message_level = soplex::SPxOut::INFO2;
+      break;
+    case MESSAGE_VERBOSE:
+      _message_level = soplex::SPxOut::DEBUG;
+      break;
+    }
+  }
+
+  void SoplexLp::_applyMessageLevel() {
+    soplex::Param::setVerbose(_message_level);
+  }
+
+} //namespace lemon
+