test/mip_test.cc
author deba
Tue, 06 Mar 2007 17:04:16 +0000
changeset 2395 fe5966d8acfc
parent 2386 81b47fc5c444
child 2441 d8d6ab871608
permissions -rw-r--r--
Correction of urls and email addresses
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2007
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 #include "test_tools.h"
    20 
    21 
    22 #ifdef HAVE_CONFIG_H
    23 #include <config.h>
    24 #endif
    25 
    26 #ifdef HAVE_CPLEX
    27 #include <lemon/mip_cplex.h>
    28 #endif
    29 
    30 #ifdef HAVE_GLPK
    31 #include <lemon/mip_glpk.h>
    32 #endif
    33 
    34 
    35 using namespace lemon;
    36 
    37 void solveAndCheck(MipSolverBase& lp, MipSolverBase::SolutionStatus stat, 
    38 		   double exp_opt) {
    39   using std::string;
    40 
    41   lp.solve();
    42   //int decimal,sign;
    43   std::ostringstream buf;
    44   buf << "Primalstatus should be: " << int(stat)<<" and it is "<<int(lp.primalStatus());
    45 
    46 
    47   //  itoa(stat,buf1, 10);
    48   check(lp.mipStatus()==stat, buf.str());
    49 
    50   if (stat ==  MipSolverBase::OPTIMAL) {
    51     std::ostringstream sbuf;
    52     buf << "Wrong optimal value: the right optimum is " << exp_opt; 
    53     check(std::abs(lp.primalValue()-exp_opt) < 1e-3, sbuf.str());
    54     //+ecvt(exp_opt,2)
    55   }
    56 }
    57 
    58 void aTest(MipSolverBase& mip)
    59 {
    60  //The following example is very simple
    61 
    62 
    63   typedef MipSolverBase::Row Row;
    64   typedef MipSolverBase::Col Col;
    65 
    66 
    67 
    68   Col x1 = mip.addCol();
    69   Col x2 = mip.addCol();
    70 
    71 
    72   //Objective function
    73   mip.obj(x1);
    74 
    75   mip.max();
    76 
    77 
    78   //Unconstrained optimization
    79   mip.solve();
    80   //Check it out!
    81 
    82   //Constraints
    83   mip.addRow(2*x1+x2 <=2);  
    84   mip.addRow(x1-2*x2 <=0);  
    85 
    86   //Nonnegativity of the variable x1
    87   mip.colLowerBound(x1, 0);
    88 
    89 
    90 
    91   //Maximization of x1
    92   //over the triangle with vertices (0,0),(4/5,2/5),(0,2)
    93   double expected_opt=4.0/5.0;
    94   solveAndCheck(mip, MipSolverBase::OPTIMAL, expected_opt);
    95 
    96   //Restrict x2 to integer
    97   mip.colType(x2,MipSolverBase::INT);  
    98   expected_opt=1.0/2.0;
    99   solveAndCheck(mip, MipSolverBase::OPTIMAL, expected_opt);
   100 
   101 
   102   //Restrict both to integer
   103   mip.colType(x1,MipSolverBase::INT);  
   104   expected_opt=0;
   105   solveAndCheck(mip, MipSolverBase::OPTIMAL, expected_opt);
   106 
   107  
   108 
   109 }
   110 
   111 
   112 int main() 
   113 {
   114 
   115 #ifdef HAVE_GLPK
   116   MipGlpk mip1;
   117   aTest(mip1);
   118 #endif
   119 
   120 #ifdef HAVE_CPLEX
   121   MipCplex mip2;
   122   aTest(mip2);
   123 #endif
   124 
   125   return 0;
   126 
   127 }