lemon/lp_cplex.cc
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Fri, 18 Nov 2005 11:13:11 +0000
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     1 /* -*- C++ -*-
     2  * lemon/lp_cplex.cc - Part of LEMON, a generic C++ optimization library
     3  *
     4  * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     5  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     6  *
     7  * Permission to use, modify and distribute this software is granted
     8  * provided that this copyright notice appears in all copies. For
     9  * precise terms see the accompanying LICENSE file.
    10  *
    11  * This software is provided "AS IS" with no warranty of any kind,
    12  * express or implied, and with no claim as to its suitability for any
    13  * purpose.
    14  *
    15  */
    16 #include <iostream>
    17 #include<lemon/lp_cplex.h>
    18 
    19 ///\file
    20 ///\brief Implementation of the LEMON-CPLEX lp solver interface.
    21 namespace lemon {
    22   
    23   LpCplex::LpCplex() : LpSolverBase() {
    24 
    25     //    env = CPXopenCPLEXdevelop(&status);     
    26     env = CPXopenCPLEX(&status);     
    27     lp = CPXcreateprob(env, &status, "LP problem");
    28   }
    29   
    30   LpCplex::~LpCplex() {
    31     CPXfreeprob(env,&lp); 
    32     CPXcloseCPLEX(&env); 
    33   }
    34   
    35   LpSolverBase &LpCplex::_newLp() 
    36   {
    37     //The first approach opens a new environment
    38     LpCplex* newlp=new LpCplex();
    39     return *newlp;
    40   }
    41 
    42   LpSolverBase &LpCplex::_copyLp() {
    43     //The first approach opens a new environment
    44     LpCplex* newlp=new LpCplex();
    45     //The routine CPXcloneprob can be used to create a new CPLEX problem 
    46     //object and copy all the problem data from an existing problem 
    47     //object to it. Solution and starting information is not copied.
    48     newlp->lp = CPXcloneprob(env, lp, &status);
    49     return *newlp;
    50   }
    51 
    52   int LpCplex::_addCol()
    53   {
    54     int i = CPXgetnumcols(env, lp);
    55     Value lb[1],ub[1];
    56     lb[0]=-INF;//-CPX_INFBOUND;
    57     ub[0]=INF;//CPX_INFBOUND;
    58     status = CPXnewcols(env, lp, 1, NULL, lb, ub, NULL, NULL);
    59     return i;
    60   }
    61 
    62   
    63   int LpCplex::_addRow() 
    64   {
    65     //We want a row that is not constrained
    66     char sense[1];
    67     sense[0]='L';//<= constraint
    68     Value rhs[1];
    69     rhs[0]=INF;
    70     int i = CPXgetnumrows(env, lp);
    71     status = CPXnewrows(env, lp, 1, rhs, sense, NULL, NULL);
    72     return i;
    73   }
    74 
    75 
    76   void LpCplex::_eraseCol(int i) {
    77     CPXdelcols(env, lp, i, i);
    78   }
    79   
    80   void LpCplex::_eraseRow(int i) {
    81     CPXdelrows(env, lp, i, i);
    82   }
    83 
    84   
    85   ///\warning Data at index 0 is ignored in the arrays.
    86   void LpCplex::_setRowCoeffs(int i, 
    87 			      int length,
    88 			      int  const * indices, 
    89 			      Value  const * values )
    90   {
    91     int rowlist[length+1];
    92     int* p=rowlist;
    93     for (int k=1;k<=length;++k){
    94       rowlist[k]=i;
    95     }
    96     status = CPXchgcoeflist(env, lp, 
    97 			    length, 
    98 			    p+1, 
    99 			    const_cast<int * >(indices+1), 
   100 			    const_cast<Value * >(values+1));
   101   }
   102   
   103   void LpCplex::_setColCoeffs(int i, 
   104 			      int length,
   105 			      int  const * indices, 
   106 			      Value  const * values)
   107   {
   108     int collist[length+1];
   109     int* p=collist;
   110     for (int k=1;k<=length;++k){
   111       collist[k]=i;
   112     }
   113     status = CPXchgcoeflist(env, lp, 
   114 			    length, 
   115 			    const_cast<int * >(indices+1), 
   116 			    p+1, 
   117 			    const_cast<Value * >(values+1));
   118   }
   119   
   120   void LpCplex::_setCoeff(int row, int col, Value value) 
   121   {
   122     CPXchgcoef(env, lp, row, col, value);
   123   }
   124 
   125   void LpCplex::_setColLowerBound(int i, Value value)
   126   {
   127     int indices[1];
   128     indices[0]=i;
   129     char lu[1];
   130     lu[0]='L';
   131     Value bd[1];
   132     bd[0]=value;
   133     status = CPXchgbds(env, lp, 1, indices, lu, bd);
   134  
   135   }
   136   
   137   void LpCplex::_setColUpperBound(int i, Value value)
   138   {
   139     int indices[1];
   140     indices[0]=i;
   141     char lu[1];
   142     lu[0]='U';
   143     Value bd[1];
   144     bd[0]=value;
   145     status = CPXchgbds(env, lp, 1, indices, lu, bd);
   146   }
   147 
   148   //This will be easier to implement
   149   void LpCplex::_setRowBounds(int i, Value lb, Value ub)
   150   {
   151     //Bad parameter
   152     if (lb==INF || ub==-INF) {
   153       //FIXME error
   154     }
   155     
   156     int cnt=1;
   157     int indices[1];
   158     indices[0]=i;
   159     char sense[1];
   160 
   161     if (lb==-INF){
   162       sense[0]='L';
   163       CPXchgsense(env, lp, cnt, indices, sense);
   164       CPXchgcoef(env, lp, i, -1, ub);
   165       
   166     }
   167     else{
   168       if (ub==INF){
   169 	sense[0]='G';
   170 	CPXchgsense(env, lp, cnt, indices, sense);
   171 	CPXchgcoef(env, lp, i, -1, lb);
   172       }
   173       else{
   174 	if (lb == ub){
   175 	  sense[0]='E';
   176 	  CPXchgsense(env, lp, cnt, indices, sense);
   177 	  CPXchgcoef(env, lp, i, -1, lb);
   178 	}
   179 	else{
   180 	  sense[0]='R';
   181 	  CPXchgsense(env, lp, cnt, indices, sense);
   182 	  CPXchgcoef(env, lp, i, -1, lb);
   183 	  CPXchgcoef(env, lp, i, -2, ub-lb);	  
   184 	}
   185       }
   186     }
   187   }
   188 
   189 //   void LpCplex::_setRowLowerBound(int i, Value value)
   190 //   {
   191 //     //Not implemented, obsolete
   192 //   }
   193   
   194 //   void LpCplex::_setRowUpperBound(int i, Value value)
   195 //   {
   196 //     //Not implemented, obsolete
   197 // //     //TODO Ezt kell meg megirni
   198 // //     //type of the problem
   199 // //     char sense[1];
   200 // //     status = CPXgetsense(env, lp, sense, i, i);
   201 // //     Value rhs[1];
   202 // //     status = CPXgetrhs(env, lp, rhs, i, i);
   203 
   204 // //     switch (sense[0]) {
   205 // //     case 'L'://<= constraint
   206 // //       break;
   207 // //     case 'E'://= constraint
   208 // //       break;
   209 // //     case 'G'://>= constraint
   210 // //       break;
   211 // //     case 'R'://ranged constraint
   212 // //       break;
   213 // //     default: ;
   214 // //       //FIXME error
   215 // //     }
   216 
   217 // //     status = CPXchgcoef(env, lp, i, -2, value_rng);
   218 //   }
   219   
   220   void LpCplex::_setObjCoeff(int i, Value obj_coef)
   221   {
   222     CPXchgcoef(env, lp, -1, i, obj_coef);
   223   }
   224 
   225   void LpCplex::_clearObj()
   226   {
   227     for (int i=0;i< CPXgetnumcols(env, lp);++i){
   228       CPXchgcoef(env, lp, -1, i, 0);
   229     }
   230     
   231   }
   232   // The routine returns zero unless an error occurred during the
   233   // optimization. Examples of errors include exhausting available
   234   // memory (CPXERR_NO_MEMORY) or encountering invalid data in the
   235   // CPLEX problem object (CPXERR_NO_PROBLEM). Exceeding a
   236   // user-specified CPLEX limit, or proving the model infeasible or
   237   // unbounded, are not considered errors. Note that a zero return
   238   // value does not necessarily mean that a solution exists. Use query
   239   // routines CPXsolninfo, CPXgetstat, and CPXsolution to obtain
   240   // further information about the status of the optimization.
   241   LpCplex::SolveExitStatus LpCplex::_solve()
   242   {
   243     //CPX_PARAM_LPMETHOD 
   244     status = CPXlpopt(env, lp);
   245     //status = CPXprimopt(env, lp);
   246     if (status == 0){
   247       //We want to exclude some cases
   248       switch (CPXgetstat(env, lp)){
   249       case CPX_OBJ_LIM:
   250       case CPX_IT_LIM_FEAS:
   251       case CPX_IT_LIM_INFEAS:               
   252       case CPX_TIME_LIM_FEAS:
   253       case CPX_TIME_LIM_INFEAS:
   254 	return UNSOLVED;
   255       default:
   256 	return SOLVED; 
   257       }
   258     }
   259     else{
   260       return UNSOLVED;
   261     }
   262   }
   263 
   264   LpCplex::Value LpCplex::_getPrimal(int i)
   265   {
   266     Value x;
   267     CPXgetx(env, lp, &x, i, i);
   268     return x;
   269   }
   270 
   271   LpCplex::Value LpCplex::_getDual(int i)
   272   {
   273     Value y;
   274     CPXgetpi(env, lp, &y, i, i);
   275     return y;
   276   }
   277   
   278   LpCplex::Value LpCplex::_getPrimalValue()
   279   {
   280     Value objval;
   281     //method = CPXgetmethod (env, lp);
   282     //printf("CPXgetprobtype %d \n",CPXgetprobtype(env,lp));
   283     status = CPXgetobjval(env, lp, &objval);
   284     //printf("Objective value: %g \n",objval);
   285     return objval;
   286   }
   287   
   288 
   289 //7.5-os cplex statusai (Vigyazat: a 9.0-asei masok!)
   290 // 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.
   291 
   292 // For Simplex, Barrier  
   293 // 1  	CPX_OPTIMAL  
   294 // 	 Optimal solution found  
   295 // 2  	CPX_INFEASIBLE  
   296 // 	 Problem infeasible  
   297 // 3    CPX_UNBOUNDED  
   298 // 	 Problem unbounded  
   299 // 4  	CPX_OBJ_LIM  
   300 // 	 Objective limit exceeded in Phase II  
   301 // 5  	CPX_IT_LIM_FEAS  
   302 // 	 Iteration limit exceeded in Phase II  
   303 // 6  	CPX_IT_LIM_INFEAS  
   304 // 	 Iteration limit exceeded in Phase I  
   305 // 7  	CPX_TIME_LIM_FEAS  
   306 // 	 Time limit exceeded in Phase II  
   307 // 8  	CPX_TIME_LIM_INFEAS  
   308 // 	 Time limit exceeded in Phase I  
   309 // 9  	CPX_NUM_BEST_FEAS  
   310 // 	 Problem non-optimal, singularities in Phase II  
   311 // 10 	CPX_NUM_BEST_INFEAS  
   312 // 	 Problem non-optimal, singularities in Phase I  
   313 // 11 	CPX_OPTIMAL_INFEAS  
   314 // 	 Optimal solution found, unscaled infeasibilities  
   315 // 12 	CPX_ABORT_FEAS  
   316 // 	 Aborted in Phase II  
   317 // 13 	CPX_ABORT_INFEAS  
   318 // 	 Aborted in Phase I  
   319 // 14  	CPX_ABORT_DUAL_INFEAS  
   320 // 	 Aborted in barrier, dual infeasible  
   321 // 15  	CPX_ABORT_PRIM_INFEAS  
   322 // 	 Aborted in barrier, primal infeasible  
   323 // 16  	CPX_ABORT_PRIM_DUAL_INFEAS  
   324 // 	 Aborted in barrier, primal and dual infeasible  
   325 // 17  	CPX_ABORT_PRIM_DUAL_FEAS  
   326 // 	 Aborted in barrier, primal and dual feasible  
   327 // 18  	CPX_ABORT_CROSSOVER  
   328 // 	 Aborted in crossover  
   329 // 19  	CPX_INForUNBD  
   330 // 	 Infeasible or unbounded  
   331 // 20   CPX_PIVOT
   332 //       User pivot used
   333 //
   334 //     Ezeket hova tegyem:
   335 // ??case CPX_ABORT_DUAL_INFEAS           
   336 // ??case CPX_ABORT_CROSSOVER             
   337 // ??case CPX_INForUNBD                   
   338 // ??case CPX_PIVOT              
   339          
   340 //Some more interesting stuff:
   341 
   342 // CPX_PARAM_LPMETHOD  1062  int  LPMETHOD
   343 // 0 Automatic 
   344 // 1 Primal Simplex 
   345 // 2 Dual Simplex 
   346 // 3 Network Simplex 
   347 // 4 Standard Barrier 
   348 // Default: 0 
   349 // Description: Method for linear optimization. 
   350 // 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 
   351   //Hulye cplex
   352   void statusSwitch(CPXENVptr env,int& stat){
   353     int lpmethod;
   354     CPXgetintparam (env,CPX_PARAM_LPMETHOD,&lpmethod);
   355     if (lpmethod==2){
   356       if (stat==CPX_UNBOUNDED){
   357 	stat=CPX_INFEASIBLE;
   358       }
   359       else{
   360 	if (stat==CPX_INFEASIBLE)
   361 	  stat=CPX_UNBOUNDED;
   362       }
   363     }
   364   }
   365 
   366   LpCplex::SolutionStatus LpCplex::_getPrimalStatus()
   367   {
   368     
   369     int stat = CPXgetstat(env, lp);
   370     statusSwitch(env,stat);
   371     //CPXgetstat(env, lp);
   372     //printf("A primal status: %d, CPX_OPTIMAL=%d \n",stat,CPX_OPTIMAL);
   373     switch (stat) {
   374     case 0:
   375       return UNDEFINED; //Undefined
   376     case CPX_OPTIMAL://Optimal
   377       return OPTIMAL;
   378     case CPX_UNBOUNDED://Unbounded
   379       return INFEASIBLE;//In case of dual simplex
   380       //return INFINITE;
   381     case CPX_INFEASIBLE://Infeasible 
   382  //    case CPX_IT_LIM_INFEAS:
   383 //     case CPX_TIME_LIM_INFEAS:
   384 //     case CPX_NUM_BEST_INFEAS:             
   385 //     case CPX_OPTIMAL_INFEAS:              
   386 //     case CPX_ABORT_INFEAS:                
   387 //     case CPX_ABORT_PRIM_INFEAS:           
   388 //     case CPX_ABORT_PRIM_DUAL_INFEAS:      
   389       return INFINITE;//In case of dual simplex
   390       //return INFEASIBLE;
   391 //     case CPX_OBJ_LIM:                    
   392 //     case CPX_IT_LIM_FEAS:             
   393 //     case CPX_TIME_LIM_FEAS:                
   394 //     case CPX_NUM_BEST_FEAS:                
   395 //     case CPX_ABORT_FEAS:                  
   396 //     case CPX_ABORT_PRIM_DUAL_FEAS:        
   397 //       return FEASIBLE;
   398     default:
   399       return UNDEFINED; //Everything else comes here
   400       //FIXME error
   401     }
   402 
   403   }
   404 
   405 //9.0-as cplex verzio statusai
   406 // CPX_STAT_ABORT_DUAL_OBJ_LIM
   407 // CPX_STAT_ABORT_IT_LIM
   408 // CPX_STAT_ABORT_OBJ_LIM
   409 // CPX_STAT_ABORT_PRIM_OBJ_LIM
   410 // CPX_STAT_ABORT_TIME_LIM
   411 // CPX_STAT_ABORT_USER
   412 // CPX_STAT_FEASIBLE_RELAXED
   413 // CPX_STAT_INFEASIBLE
   414 // CPX_STAT_INForUNBD
   415 // CPX_STAT_NUM_BEST
   416 // CPX_STAT_OPTIMAL
   417 // CPX_STAT_OPTIMAL_FACE_UNBOUNDED
   418 // CPX_STAT_OPTIMAL_INFEAS
   419 // CPX_STAT_OPTIMAL_RELAXED
   420 // CPX_STAT_UNBOUNDED
   421 
   422   LpCplex::SolutionStatus LpCplex::_getDualStatus()
   423   {
   424     int stat = CPXgetstat(env, lp);
   425     statusSwitch(env,stat);
   426     switch (stat) {
   427     case 0:
   428       return UNDEFINED; //Undefined
   429     case CPX_OPTIMAL://Optimal
   430       return OPTIMAL;
   431     case CPX_UNBOUNDED:
   432      return INFEASIBLE;
   433     default:
   434       return UNDEFINED; //Everything else comes here
   435       //FIXME error
   436     }
   437   }
   438 
   439   LpCplex::ProblemTypes LpCplex::_getProblemType()
   440   {
   441     int stat = CPXgetstat(env, lp);
   442     switch (stat) {
   443     case CPX_OPTIMAL://Optimal
   444 	return PRIMAL_DUAL_FEASIBLE;
   445     case CPX_UNBOUNDED:
   446  	return PRIMAL_FEASIBLE_DUAL_INFEASIBLE;
   447 // 	return PRIMAL_INFEASIBLE_DUAL_FEASIBLE;
   448 // 	return PRIMAL_DUAL_INFEASIBLE;
   449 
   450 //Seems to be that this is all we can say for sure
   451     default:
   452 	//In all other cases
   453 	return UNKNOWN;
   454       //FIXME error
   455     }
   456   }
   457 
   458   void LpCplex::_setMax()
   459   {
   460     CPXchgobjsen(env, lp, CPX_MAX);
   461    }
   462   void LpCplex::_setMin()
   463   {
   464     CPXchgobjsen(env, lp, CPX_MIN);
   465    }
   466   
   467 } //namespace lemon
   468