diff -r c6acc34f98dc -r 1a7fe3bef514 lemon/cplex.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lemon/cplex.cc	Thu Nov 05 15:50:01 2009 +0100
@@ -0,0 +1,984 @@
+/* -*- mode: C++; indent-tabs-mode: nil; -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library.
+ *
+ * Copyright (C) 2003-2009
+ * 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 <vector>
+#include <cstring>
+
+#include <lemon/cplex.h>
+
+extern "C" {
+#include <ilcplex/cplex.h>
+}
+
+
+///\file
+///\brief Implementation of the LEMON-CPLEX lp solver interface.
+namespace lemon {
+
+  CplexEnv::LicenseError::LicenseError(int status) {
+    if (!CPXgeterrorstring(0, status, _message)) {
+      std::strcpy(_message, "Cplex unknown error");
+    }
+  }
+
+  CplexEnv::CplexEnv() {
+    int status;
+    _cnt = new int;
+    _env = CPXopenCPLEX(&status);
+    if (_env == 0) {
+      delete _cnt;
+      _cnt = 0;
+      throw LicenseError(status);
+    }
+  }
+
+  CplexEnv::CplexEnv(const CplexEnv& other) {
+    _env = other._env;
+    _cnt = other._cnt;
+    ++(*_cnt);
+  }
+
+  CplexEnv& CplexEnv::operator=(const CplexEnv& other) {
+    _env = other._env;
+    _cnt = other._cnt;
+    ++(*_cnt);
+    return *this;
+  }
+
+  CplexEnv::~CplexEnv() {
+    --(*_cnt);
+    if (*_cnt == 0) {
+      delete _cnt;
+      CPXcloseCPLEX(&_env);
+    }
+  }
+
+  CplexBase::CplexBase() : LpBase() {
+    int status;
+    _prob = CPXcreateprob(cplexEnv(), &status, "Cplex problem");
+    messageLevel(MESSAGE_NOTHING);
+  }
+
+  CplexBase::CplexBase(const CplexEnv& env)
+    : LpBase(), _env(env) {
+    int status;
+    _prob = CPXcreateprob(cplexEnv(), &status, "Cplex problem");
+    messageLevel(MESSAGE_NOTHING);
+  }
+
+  CplexBase::CplexBase(const CplexBase& cplex)
+    : LpBase() {
+    int status;
+    _prob = CPXcloneprob(cplexEnv(), cplex._prob, &status);
+    rows = cplex.rows;
+    cols = cplex.cols;
+    messageLevel(MESSAGE_NOTHING);
+  }
+
+  CplexBase::~CplexBase() {
+    CPXfreeprob(cplexEnv(),&_prob);
+  }
+
+  int CplexBase::_addCol() {
+    int i = CPXgetnumcols(cplexEnv(), _prob);
+    double lb = -INF, ub = INF;
+    CPXnewcols(cplexEnv(), _prob, 1, 0, &lb, &ub, 0, 0);
+    return i;
+  }
+
+
+  int CplexBase::_addRow() {
+    int i = CPXgetnumrows(cplexEnv(), _prob);
+    const double ub = INF;
+    const char s = 'L';
+    CPXnewrows(cplexEnv(), _prob, 1, &ub, &s, 0, 0);
+    return i;
+  }
+
+  int CplexBase::_addRow(Value lb, ExprIterator b, 
+                         ExprIterator e, Value ub) {
+    int i = CPXgetnumrows(cplexEnv(), _prob);
+    if (lb == -INF) {
+      const char s = 'L';
+      CPXnewrows(cplexEnv(), _prob, 1, &ub, &s, 0, 0);
+    } else if (ub == INF) {
+      const char s = 'G';
+      CPXnewrows(cplexEnv(), _prob, 1, &lb, &s, 0, 0);
+    } else if (lb == ub){
+      const char s = 'E';
+      CPXnewrows(cplexEnv(), _prob, 1, &lb, &s, 0, 0);
+    } else {
+      const char s = 'R';
+      double len = ub - lb;
+      CPXnewrows(cplexEnv(), _prob, 1, &lb, &s, &len, 0);
+    }
+
+    std::vector<int> indices;
+    std::vector<int> rowlist;
+    std::vector<Value> values;
+
+    for(ExprIterator it=b; it!=e; ++it) {
+      indices.push_back(it->first);
+      values.push_back(it->second);
+      rowlist.push_back(i);
+    }
+
+    CPXchgcoeflist(cplexEnv(), _prob, values.size(),
+                   &rowlist.front(), &indices.front(), &values.front());
+
+    return i;
+  }
+
+  void CplexBase::_eraseCol(int i) {
+    CPXdelcols(cplexEnv(), _prob, i, i);
+  }
+
+  void CplexBase::_eraseRow(int i) {
+    CPXdelrows(cplexEnv(), _prob, i, i);
+  }
+
+  void CplexBase::_eraseColId(int i) {
+    cols.eraseIndex(i);
+    cols.shiftIndices(i);
+  }
+  void CplexBase::_eraseRowId(int i) {
+    rows.eraseIndex(i);
+    rows.shiftIndices(i);
+  }
+
+  void CplexBase::_getColName(int col, std::string &name) const {
+    int size;
+    CPXgetcolname(cplexEnv(), _prob, 0, 0, 0, &size, col, col);
+    if (size == 0) {
+      name.clear();
+      return;
+    }
+
+    size *= -1;
+    std::vector<char> buf(size);
+    char *cname;
+    int tmp;
+    CPXgetcolname(cplexEnv(), _prob, &cname, &buf.front(), size,
+                  &tmp, col, col);
+    name = cname;
+  }
+
+  void CplexBase::_setColName(int col, const std::string &name) {
+    char *cname;
+    cname = const_cast<char*>(name.c_str());
+    CPXchgcolname(cplexEnv(), _prob, 1, &col, &cname);
+  }
+
+  int CplexBase::_colByName(const std::string& name) const {
+    int index;
+    if (CPXgetcolindex(cplexEnv(), _prob,
+                       const_cast<char*>(name.c_str()), &index) == 0) {
+      return index;
+    }
+    return -1;
+  }
+
+  void CplexBase::_getRowName(int row, std::string &name) const {
+    int size;
+    CPXgetrowname(cplexEnv(), _prob, 0, 0, 0, &size, row, row);
+    if (size == 0) {
+      name.clear();
+      return;
+    }
+
+    size *= -1;
+    std::vector<char> buf(size);
+    char *cname;
+    int tmp;
+    CPXgetrowname(cplexEnv(), _prob, &cname, &buf.front(), size,
+                  &tmp, row, row);
+    name = cname;
+  }
+
+  void CplexBase::_setRowName(int row, const std::string &name) {
+    char *cname;
+    cname = const_cast<char*>(name.c_str());
+    CPXchgrowname(cplexEnv(), _prob, 1, &row, &cname);
+  }
+
+  int CplexBase::_rowByName(const std::string& name) const {
+    int index;
+    if (CPXgetrowindex(cplexEnv(), _prob,
+                       const_cast<char*>(name.c_str()), &index) == 0) {
+      return index;
+    }
+    return -1;
+  }
+
+  void CplexBase::_setRowCoeffs(int i, ExprIterator b,
+                                      ExprIterator e)
+  {
+    std::vector<int> indices;
+    std::vector<int> rowlist;
+    std::vector<Value> values;
+
+    for(ExprIterator it=b; it!=e; ++it) {
+      indices.push_back(it->first);
+      values.push_back(it->second);
+      rowlist.push_back(i);
+    }
+
+    CPXchgcoeflist(cplexEnv(), _prob, values.size(),
+                   &rowlist.front(), &indices.front(), &values.front());
+  }
+
+  void CplexBase::_getRowCoeffs(int i, InsertIterator b) const {
+    int tmp1, tmp2, tmp3, length;
+    CPXgetrows(cplexEnv(), _prob, &tmp1, &tmp2, 0, 0, 0, &length, i, i);
+
+    length = -length;
+    std::vector<int> indices(length);
+    std::vector<double> values(length);
+
+    CPXgetrows(cplexEnv(), _prob, &tmp1, &tmp2,
+               &indices.front(), &values.front(),
+               length, &tmp3, i, i);
+
+    for (int i = 0; i < length; ++i) {
+      *b = std::make_pair(indices[i], values[i]);
+      ++b;
+    }
+  }
+
+  void CplexBase::_setColCoeffs(int i, ExprIterator b, ExprIterator e) {
+    std::vector<int> indices;
+    std::vector<int> collist;
+    std::vector<Value> values;
+
+    for(ExprIterator it=b; it!=e; ++it) {
+      indices.push_back(it->first);
+      values.push_back(it->second);
+      collist.push_back(i);
+    }
+
+    CPXchgcoeflist(cplexEnv(), _prob, values.size(),
+                   &indices.front(), &collist.front(), &values.front());
+  }
+
+  void CplexBase::_getColCoeffs(int i, InsertIterator b) const {
+
+    int tmp1, tmp2, tmp3, length;
+    CPXgetcols(cplexEnv(), _prob, &tmp1, &tmp2, 0, 0, 0, &length, i, i);
+
+    length = -length;
+    std::vector<int> indices(length);
+    std::vector<double> values(length);
+
+    CPXgetcols(cplexEnv(), _prob, &tmp1, &tmp2,
+               &indices.front(), &values.front(),
+               length, &tmp3, i, i);
+
+    for (int i = 0; i < length; ++i) {
+      *b = std::make_pair(indices[i], values[i]);
+      ++b;
+    }
+
+  }
+
+  void CplexBase::_setCoeff(int row, int col, Value value) {
+    CPXchgcoef(cplexEnv(), _prob, row, col, value);
+  }
+
+  CplexBase::Value CplexBase::_getCoeff(int row, int col) const {
+    CplexBase::Value value;
+    CPXgetcoef(cplexEnv(), _prob, row, col, &value);
+    return value;
+  }
+
+  void CplexBase::_setColLowerBound(int i, Value value) {
+    const char s = 'L';
+    CPXchgbds(cplexEnv(), _prob, 1, &i, &s, &value);
+  }
+
+  CplexBase::Value CplexBase::_getColLowerBound(int i) const {
+    CplexBase::Value res;
+    CPXgetlb(cplexEnv(), _prob, &res, i, i);
+    return res <= -CPX_INFBOUND ? -INF : res;
+  }
+
+  void CplexBase::_setColUpperBound(int i, Value value)
+  {
+    const char s = 'U';
+    CPXchgbds(cplexEnv(), _prob, 1, &i, &s, &value);
+  }
+
+  CplexBase::Value CplexBase::_getColUpperBound(int i) const {
+    CplexBase::Value res;
+    CPXgetub(cplexEnv(), _prob, &res, i, i);
+    return res >= CPX_INFBOUND ? INF : res;
+  }
+
+  CplexBase::Value CplexBase::_getRowLowerBound(int i) const {
+    char s;
+    CPXgetsense(cplexEnv(), _prob, &s, i, i);
+    CplexBase::Value res;
+
+    switch (s) {
+    case 'G':
+    case 'R':
+    case 'E':
+      CPXgetrhs(cplexEnv(), _prob, &res, i, i);
+      return res <= -CPX_INFBOUND ? -INF : res;
+    default:
+      return -INF;
+    }
+  }
+
+  CplexBase::Value CplexBase::_getRowUpperBound(int i) const {
+    char s;
+    CPXgetsense(cplexEnv(), _prob, &s, i, i);
+    CplexBase::Value res;
+
+    switch (s) {
+    case 'L':
+    case 'E':
+      CPXgetrhs(cplexEnv(), _prob, &res, i, i);
+      return res >= CPX_INFBOUND ? INF : res;
+    case 'R':
+      CPXgetrhs(cplexEnv(), _prob, &res, i, i);
+      {
+        double rng;
+        CPXgetrngval(cplexEnv(), _prob, &rng, i, i);
+        res += rng;
+      }
+      return res >= CPX_INFBOUND ? INF : res;
+    default:
+      return INF;
+    }
+  }
+
+  //This is easier to implement
+  void CplexBase::_set_row_bounds(int i, Value lb, Value ub) {
+    if (lb == -INF) {
+      const char s = 'L';
+      CPXchgsense(cplexEnv(), _prob, 1, &i, &s);
+      CPXchgrhs(cplexEnv(), _prob, 1, &i, &ub);
+    } else if (ub == INF) {
+      const char s = 'G';
+      CPXchgsense(cplexEnv(), _prob, 1, &i, &s);
+      CPXchgrhs(cplexEnv(), _prob, 1, &i, &lb);
+    } else if (lb == ub){
+      const char s = 'E';
+      CPXchgsense(cplexEnv(), _prob, 1, &i, &s);
+      CPXchgrhs(cplexEnv(), _prob, 1, &i, &lb);
+    } else {
+      const char s = 'R';
+      CPXchgsense(cplexEnv(), _prob, 1, &i, &s);
+      CPXchgrhs(cplexEnv(), _prob, 1, &i, &lb);
+      double len = ub - lb;
+      CPXchgrngval(cplexEnv(), _prob, 1, &i, &len);
+    }
+  }
+
+  void CplexBase::_setRowLowerBound(int i, Value lb)
+  {
+    LEMON_ASSERT(lb != INF, "Invalid bound");
+    _set_row_bounds(i, lb, CplexBase::_getRowUpperBound(i));
+  }
+
+  void CplexBase::_setRowUpperBound(int i, Value ub)
+  {
+
+    LEMON_ASSERT(ub != -INF, "Invalid bound");
+    _set_row_bounds(i, CplexBase::_getRowLowerBound(i), ub);
+  }
+
+  void CplexBase::_setObjCoeffs(ExprIterator b, ExprIterator e)
+  {
+    std::vector<int> indices;
+    std::vector<Value> values;
+    for(ExprIterator it=b; it!=e; ++it) {
+      indices.push_back(it->first);
+      values.push_back(it->second);
+    }
+    CPXchgobj(cplexEnv(), _prob, values.size(),
+              &indices.front(), &values.front());
+
+  }
+
+  void CplexBase::_getObjCoeffs(InsertIterator b) const
+  {
+    int num = CPXgetnumcols(cplexEnv(), _prob);
+    std::vector<Value> x(num);
+
+    CPXgetobj(cplexEnv(), _prob, &x.front(), 0, num - 1);
+    for (int i = 0; i < num; ++i) {
+      if (x[i] != 0.0) {
+        *b = std::make_pair(i, x[i]);
+        ++b;
+      }
+    }
+  }
+
+  void CplexBase::_setObjCoeff(int i, Value obj_coef)
+  {
+    CPXchgobj(cplexEnv(), _prob, 1, &i, &obj_coef);
+  }
+
+  CplexBase::Value CplexBase::_getObjCoeff(int i) const
+  {
+    Value x;
+    CPXgetobj(cplexEnv(), _prob, &x, i, i);
+    return x;
+  }
+
+  void CplexBase::_setSense(CplexBase::Sense sense) {
+    switch (sense) {
+    case MIN:
+      CPXchgobjsen(cplexEnv(), _prob, CPX_MIN);
+      break;
+    case MAX:
+      CPXchgobjsen(cplexEnv(), _prob, CPX_MAX);
+      break;
+    }
+  }
+
+  CplexBase::Sense CplexBase::_getSense() const {
+    switch (CPXgetobjsen(cplexEnv(), _prob)) {
+    case CPX_MIN:
+      return MIN;
+    case CPX_MAX:
+      return MAX;
+    default:
+      LEMON_ASSERT(false, "Invalid sense");
+      return CplexBase::Sense();
+    }
+  }
+
+  void CplexBase::_clear() {
+    CPXfreeprob(cplexEnv(),&_prob);
+    int status;
+    _prob = CPXcreateprob(cplexEnv(), &status, "Cplex problem");
+    rows.clear();
+    cols.clear();
+  }
+
+  void CplexBase::_messageLevel(MessageLevel level) {
+    switch (level) {
+    case MESSAGE_NOTHING:
+      _message_enabled = false;
+      break;
+    case MESSAGE_ERROR:
+    case MESSAGE_WARNING:
+    case MESSAGE_NORMAL:
+    case MESSAGE_VERBOSE:
+      _message_enabled = true;
+      break;
+    }
+  }
+
+  void CplexBase::_applyMessageLevel() {
+    CPXsetintparam(cplexEnv(), CPX_PARAM_SCRIND, 
+                   _message_enabled ? CPX_ON : CPX_OFF);
+  }
+
+  // CplexLp members
+
+  CplexLp::CplexLp()
+    : LpBase(), LpSolver(), CplexBase() {}
+
+  CplexLp::CplexLp(const CplexEnv& env)
+    : LpBase(), LpSolver(), CplexBase(env) {}
+
+  CplexLp::CplexLp(const CplexLp& other)
+    : LpBase(), LpSolver(), CplexBase(other) {}
+
+  CplexLp::~CplexLp() {}
+
+  CplexLp* CplexLp::newSolver() const { return new CplexLp; }
+  CplexLp* CplexLp::cloneSolver() const {return new CplexLp(*this); }
+
+  const char* CplexLp::_solverName() const { return "CplexLp"; }
+
+  void CplexLp::_clear_temporals() {
+    _col_status.clear();
+    _row_status.clear();
+    _primal_ray.clear();
+    _dual_ray.clear();
+  }
+
+  // The routine returns zero unless an error occurred during the
+  // optimization. Examples of errors include exhausting available
+  // memory (CPXERR_NO_MEMORY) or encountering invalid data in the
+  // CPLEX problem object (CPXERR_NO_PROBLEM). Exceeding a
+  // user-specified CPLEX limit, or proving the model infeasible or
+  // unbounded, are not considered errors. Note that a zero return
+  // value does not necessarily mean that a solution exists. Use query
+  // routines CPXsolninfo, CPXgetstat, and CPXsolution to obtain
+  // further information about the status of the optimization.
+  CplexLp::SolveExitStatus CplexLp::convertStatus(int status) {
+#if CPX_VERSION >= 800
+    if (status == 0) {
+      switch (CPXgetstat(cplexEnv(), _prob)) {
+      case CPX_STAT_OPTIMAL:
+      case CPX_STAT_INFEASIBLE:
+      case CPX_STAT_UNBOUNDED:
+        return SOLVED;
+      default:
+        return UNSOLVED;
+      }
+    } else {
+      return UNSOLVED;
+    }
+#else
+    if (status == 0) {
+      //We want to exclude some cases
+      switch (CPXgetstat(cplexEnv(), _prob)) {
+      case CPX_OBJ_LIM:
+      case CPX_IT_LIM_FEAS:
+      case CPX_IT_LIM_INFEAS:
+      case CPX_TIME_LIM_FEAS:
+      case CPX_TIME_LIM_INFEAS:
+        return UNSOLVED;
+      default:
+        return SOLVED;
+      }
+    } else {
+      return UNSOLVED;
+    }
+#endif
+  }
+
+  CplexLp::SolveExitStatus CplexLp::_solve() {
+    _clear_temporals();
+    _applyMessageLevel();
+    return convertStatus(CPXlpopt(cplexEnv(), _prob));
+  }
+
+  CplexLp::SolveExitStatus CplexLp::solvePrimal() {
+    _clear_temporals();
+    _applyMessageLevel();
+    return convertStatus(CPXprimopt(cplexEnv(), _prob));
+  }
+
+  CplexLp::SolveExitStatus CplexLp::solveDual() {
+    _clear_temporals();
+    _applyMessageLevel();
+    return convertStatus(CPXdualopt(cplexEnv(), _prob));
+  }
+
+  CplexLp::SolveExitStatus CplexLp::solveBarrier() {
+    _clear_temporals();
+    _applyMessageLevel();
+    return convertStatus(CPXbaropt(cplexEnv(), _prob));
+  }
+
+  CplexLp::Value CplexLp::_getPrimal(int i) const {
+    Value x;
+    CPXgetx(cplexEnv(), _prob, &x, i, i);
+    return x;
+  }
+
+  CplexLp::Value CplexLp::_getDual(int i) const {
+    Value y;
+    CPXgetpi(cplexEnv(), _prob, &y, i, i);
+    return y;
+  }
+
+  CplexLp::Value CplexLp::_getPrimalValue() const {
+    Value objval;
+    CPXgetobjval(cplexEnv(), _prob, &objval);
+    return objval;
+  }
+
+  CplexLp::VarStatus CplexLp::_getColStatus(int i) const {
+    if (_col_status.empty()) {
+      _col_status.resize(CPXgetnumcols(cplexEnv(), _prob));
+      CPXgetbase(cplexEnv(), _prob, &_col_status.front(), 0);
+    }
+    switch (_col_status[i]) {
+    case CPX_BASIC:
+      return BASIC;
+    case CPX_FREE_SUPER:
+      return FREE;
+    case CPX_AT_LOWER:
+      return LOWER;
+    case CPX_AT_UPPER:
+      return UPPER;
+    default:
+      LEMON_ASSERT(false, "Wrong column status");
+      return CplexLp::VarStatus();
+    }
+  }
+
+  CplexLp::VarStatus CplexLp::_getRowStatus(int i) const {
+    if (_row_status.empty()) {
+      _row_status.resize(CPXgetnumrows(cplexEnv(), _prob));
+      CPXgetbase(cplexEnv(), _prob, 0, &_row_status.front());
+    }
+    switch (_row_status[i]) {
+    case CPX_BASIC:
+      return BASIC;
+    case CPX_AT_LOWER:
+      {
+        char s;
+        CPXgetsense(cplexEnv(), _prob, &s, i, i);
+        return s != 'L' ? LOWER : UPPER;
+      }
+    case CPX_AT_UPPER:
+      return UPPER;
+    default:
+      LEMON_ASSERT(false, "Wrong row status");
+      return CplexLp::VarStatus();
+    }
+  }
+
+  CplexLp::Value CplexLp::_getPrimalRay(int i) const {
+    if (_primal_ray.empty()) {
+      _primal_ray.resize(CPXgetnumcols(cplexEnv(), _prob));
+      CPXgetray(cplexEnv(), _prob, &_primal_ray.front());
+    }
+    return _primal_ray[i];
+  }
+
+  CplexLp::Value CplexLp::_getDualRay(int i) const {
+    if (_dual_ray.empty()) {
+
+    }
+    return _dual_ray[i];
+  }
+
+  // Cplex 7.0 status values
+  // This table lists the statuses, returned by the CPXgetstat()
+  // routine, for solutions to LP problems or mixed integer problems. If
+  // no solution exists, the return value is zero.
+
+  // For Simplex, Barrier
+  // 1          CPX_OPTIMAL
+  //          Optimal solution found
+  // 2          CPX_INFEASIBLE
+  //          Problem infeasible
+  // 3    CPX_UNBOUNDED
+  //          Problem unbounded
+  // 4          CPX_OBJ_LIM
+  //          Objective limit exceeded in Phase II
+  // 5          CPX_IT_LIM_FEAS
+  //          Iteration limit exceeded in Phase II
+  // 6          CPX_IT_LIM_INFEAS
+  //          Iteration limit exceeded in Phase I
+  // 7          CPX_TIME_LIM_FEAS
+  //          Time limit exceeded in Phase II
+  // 8          CPX_TIME_LIM_INFEAS
+  //          Time limit exceeded in Phase I
+  // 9          CPX_NUM_BEST_FEAS
+  //          Problem non-optimal, singularities in Phase II
+  // 10         CPX_NUM_BEST_INFEAS
+  //          Problem non-optimal, singularities in Phase I
+  // 11         CPX_OPTIMAL_INFEAS
+  //          Optimal solution found, unscaled infeasibilities
+  // 12         CPX_ABORT_FEAS
+  //          Aborted in Phase II
+  // 13         CPX_ABORT_INFEAS
+  //          Aborted in Phase I
+  // 14          CPX_ABORT_DUAL_INFEAS
+  //          Aborted in barrier, dual infeasible
+  // 15          CPX_ABORT_PRIM_INFEAS
+  //          Aborted in barrier, primal infeasible
+  // 16          CPX_ABORT_PRIM_DUAL_INFEAS
+  //          Aborted in barrier, primal and dual infeasible
+  // 17          CPX_ABORT_PRIM_DUAL_FEAS
+  //          Aborted in barrier, primal and dual feasible
+  // 18          CPX_ABORT_CROSSOVER
+  //          Aborted in crossover
+  // 19          CPX_INForUNBD
+  //          Infeasible or unbounded
+  // 20   CPX_PIVOT
+  //       User pivot used
+  //
+  // Pending return values
+  // ??case CPX_ABORT_DUAL_INFEAS
+  // ??case CPX_ABORT_CROSSOVER
+  // ??case CPX_INForUNBD
+  // ??case CPX_PIVOT
+
+  //Some more interesting stuff:
+
+  // CPX_PARAM_PROBMETHOD  1062  int  LPMETHOD
+  // 0 Automatic
+  // 1 Primal Simplex
+  // 2 Dual Simplex
+  // 3 Network Simplex
+  // 4 Standard Barrier
+  // Default: 0
+  // Description: Method for linear optimization.
+  // Determines which algorithm is used when CPXlpopt() (or "optimize"
+  // in the Interactive Optimizer) is called. Currently the behavior of
+  // the "Automatic" setting is that CPLEX simply invokes the dual
+  // simplex method, but this capability may be expanded in the future
+  // so that CPLEX chooses the method based on problem characteristics
+#if CPX_VERSION < 900
+  void statusSwitch(CPXENVptr cplexEnv(),int& stat){
+    int lpmethod;
+    CPXgetintparam (cplexEnv(),CPX_PARAM_PROBMETHOD,&lpmethod);
+    if (lpmethod==2){
+      if (stat==CPX_UNBOUNDED){
+        stat=CPX_INFEASIBLE;
+      }
+      else{
+        if (stat==CPX_INFEASIBLE)
+          stat=CPX_UNBOUNDED;
+      }
+    }
+  }
+#else
+  void statusSwitch(CPXENVptr,int&){}
+#endif
+
+  CplexLp::ProblemType CplexLp::_getPrimalType() const {
+    // Unboundedness not treated well: the following is from cplex 9.0 doc
+    // About Unboundedness
+
+    // The treatment of models that are unbounded involves a few
+    // subtleties. Specifically, a declaration of unboundedness means that
+    // ILOG CPLEX has determined that the model has an unbounded
+    // ray. Given any feasible solution x with objective z, a multiple of
+    // the unbounded ray can be added to x to give a feasible solution
+    // with objective z-1 (or z+1 for maximization models). Thus, if a
+    // feasible solution exists, then the optimal objective is
+    // unbounded. Note that ILOG CPLEX has not necessarily concluded that
+    // a feasible solution exists. Users can call the routine CPXsolninfo
+    // to determine whether ILOG CPLEX has also concluded that the model
+    // has a feasible solution.
+
+    int stat = CPXgetstat(cplexEnv(), _prob);
+#if CPX_VERSION >= 800
+    switch (stat)
+      {
+      case CPX_STAT_OPTIMAL:
+        return OPTIMAL;
+      case CPX_STAT_UNBOUNDED:
+        return UNBOUNDED;
+      case CPX_STAT_INFEASIBLE:
+        return INFEASIBLE;
+      default:
+        return UNDEFINED;
+      }
+#else
+    statusSwitch(cplexEnv(),stat);
+    //CPXgetstat(cplexEnv(), _prob);
+    switch (stat) {
+    case 0:
+      return UNDEFINED; //Undefined
+    case CPX_OPTIMAL://Optimal
+      return OPTIMAL;
+    case CPX_UNBOUNDED://Unbounded
+      return INFEASIBLE;//In case of dual simplex
+      //return UNBOUNDED;
+    case CPX_INFEASIBLE://Infeasible
+      //    case CPX_IT_LIM_INFEAS:
+      //     case CPX_TIME_LIM_INFEAS:
+      //     case CPX_NUM_BEST_INFEAS:
+      //     case CPX_OPTIMAL_INFEAS:
+      //     case CPX_ABORT_INFEAS:
+      //     case CPX_ABORT_PRIM_INFEAS:
+      //     case CPX_ABORT_PRIM_DUAL_INFEAS:
+      return UNBOUNDED;//In case of dual simplex
+      //return INFEASIBLE;
+      //     case CPX_OBJ_LIM:
+      //     case CPX_IT_LIM_FEAS:
+      //     case CPX_TIME_LIM_FEAS:
+      //     case CPX_NUM_BEST_FEAS:
+      //     case CPX_ABORT_FEAS:
+      //     case CPX_ABORT_PRIM_DUAL_FEAS:
+      //       return FEASIBLE;
+    default:
+      return UNDEFINED; //Everything else comes here
+      //FIXME error
+    }
+#endif
+  }
+
+  // Cplex 9.0 status values
+  // CPX_STAT_ABORT_DUAL_OBJ_LIM
+  // CPX_STAT_ABORT_IT_LIM
+  // CPX_STAT_ABORT_OBJ_LIM
+  // CPX_STAT_ABORT_PRIM_OBJ_LIM
+  // CPX_STAT_ABORT_TIME_LIM
+  // CPX_STAT_ABORT_USER
+  // CPX_STAT_FEASIBLE_RELAXED
+  // CPX_STAT_INFEASIBLE
+  // CPX_STAT_INForUNBD
+  // CPX_STAT_NUM_BEST
+  // CPX_STAT_OPTIMAL
+  // CPX_STAT_OPTIMAL_FACE_UNBOUNDED
+  // CPX_STAT_OPTIMAL_INFEAS
+  // CPX_STAT_OPTIMAL_RELAXED
+  // CPX_STAT_UNBOUNDED
+
+  CplexLp::ProblemType CplexLp::_getDualType() const {
+    int stat = CPXgetstat(cplexEnv(), _prob);
+#if CPX_VERSION >= 800
+    switch (stat) {
+    case CPX_STAT_OPTIMAL:
+      return OPTIMAL;
+    case CPX_STAT_UNBOUNDED:
+      return INFEASIBLE;
+    default:
+      return UNDEFINED;
+    }
+#else
+    statusSwitch(cplexEnv(),stat);
+    switch (stat) {
+    case 0:
+      return UNDEFINED; //Undefined
+    case CPX_OPTIMAL://Optimal
+      return OPTIMAL;
+    case CPX_UNBOUNDED:
+      return INFEASIBLE;
+    default:
+      return UNDEFINED; //Everything else comes here
+      //FIXME error
+    }
+#endif
+  }
+
+  // CplexMip members
+
+  CplexMip::CplexMip()
+    : LpBase(), MipSolver(), CplexBase() {
+
+#if CPX_VERSION < 800
+    CPXchgprobtype(cplexEnv(),  _prob, CPXPROB_MIP);
+#else
+    CPXchgprobtype(cplexEnv(),  _prob, CPXPROB_MILP);
+#endif
+  }
+
+  CplexMip::CplexMip(const CplexEnv& env)
+    : LpBase(), MipSolver(), CplexBase(env) {
+
+#if CPX_VERSION < 800
+    CPXchgprobtype(cplexEnv(),  _prob, CPXPROB_MIP);
+#else
+    CPXchgprobtype(cplexEnv(),  _prob, CPXPROB_MILP);
+#endif
+
+  }
+
+  CplexMip::CplexMip(const CplexMip& other)
+    : LpBase(), MipSolver(), CplexBase(other) {}
+
+  CplexMip::~CplexMip() {}
+
+  CplexMip* CplexMip::newSolver() const { return new CplexMip; }
+  CplexMip* CplexMip::cloneSolver() const {return new CplexMip(*this); }
+
+  const char* CplexMip::_solverName() const { return "CplexMip"; }
+
+  void CplexMip::_setColType(int i, CplexMip::ColTypes col_type) {
+
+    // Note If a variable is to be changed to binary, a call to CPXchgbds
+    // should also be made to change the bounds to 0 and 1.
+
+    switch (col_type){
+    case INTEGER: {
+      const char t = 'I';
+      CPXchgctype (cplexEnv(), _prob, 1, &i, &t);
+    } break;
+    case REAL: {
+      const char t = 'C';
+      CPXchgctype (cplexEnv(), _prob, 1, &i, &t);
+    } break;
+    default:
+      break;
+    }
+  }
+
+  CplexMip::ColTypes CplexMip::_getColType(int i) const {
+    char t;
+    CPXgetctype (cplexEnv(), _prob, &t, i, i);
+    switch (t) {
+    case 'I':
+      return INTEGER;
+    case 'C':
+      return REAL;
+    default:
+      LEMON_ASSERT(false, "Invalid column type");
+      return ColTypes();
+    }
+
+  }
+
+  CplexMip::SolveExitStatus CplexMip::_solve() {
+    int status;
+    _applyMessageLevel();
+    status = CPXmipopt (cplexEnv(), _prob);
+    if (status==0)
+      return SOLVED;
+    else
+      return UNSOLVED;
+
+  }
+
+
+  CplexMip::ProblemType CplexMip::_getType() const {
+
+    int stat = CPXgetstat(cplexEnv(), _prob);
+
+    //Fortunately, MIP statuses did not change for cplex 8.0
+    switch (stat) {
+    case CPXMIP_OPTIMAL:
+      // Optimal integer solution has been found.
+    case CPXMIP_OPTIMAL_TOL:
+      // Optimal soluton with the tolerance defined by epgap or epagap has
+      // been found.
+      return OPTIMAL;
+      //This also exists in later issues
+      //    case CPXMIP_UNBOUNDED:
+      //return UNBOUNDED;
+      case CPXMIP_INFEASIBLE:
+        return INFEASIBLE;
+    default:
+      return UNDEFINED;
+    }
+    //Unboundedness not treated well: the following is from cplex 9.0 doc
+    // About Unboundedness
+
+    // The treatment of models that are unbounded involves a few
+    // subtleties. Specifically, a declaration of unboundedness means that
+    // ILOG CPLEX has determined that the model has an unbounded
+    // ray. Given any feasible solution x with objective z, a multiple of
+    // the unbounded ray can be added to x to give a feasible solution
+    // with objective z-1 (or z+1 for maximization models). Thus, if a
+    // feasible solution exists, then the optimal objective is
+    // unbounded. Note that ILOG CPLEX has not necessarily concluded that
+    // a feasible solution exists. Users can call the routine CPXsolninfo
+    // to determine whether ILOG CPLEX has also concluded that the model
+    // has a feasible solution.
+  }
+
+  CplexMip::Value CplexMip::_getSol(int i) const {
+    Value x;
+    CPXgetmipx(cplexEnv(), _prob, &x, i, i);
+    return x;
+  }
+
+  CplexMip::Value CplexMip::_getSolValue() const {
+    Value objval;
+    CPXgetmipobjval(cplexEnv(), _prob, &objval);
+    return objval;
+  }
+
+} //namespace lemon
+