source: trunk/Clp/examples/decomp3.cpp @ 1326

// Copyright (C) 2008, International Business Machines
// Corporation and others.  All Rights Reserved.

#include "ClpSimplex.hpp"
#include "ClpPresolve.hpp"
#include "CoinStructuredModel.hpp"
#include "CoinTime.hpp"
#include <iomanip>

int main (int argc, const char *argv[])
{
  /* Create a structured model by reading mps file and trying
     Dantzig-Wolfe or Benders decomposition 
  */
  // Get maximum number of blocks
  int maxBlocks=50;
  if (argc>2)
    maxBlocks=atoi(argv[2]);
  int decompose=1;
  if (maxBlocks<0) {
    maxBlocks=-maxBlocks;
    decompose=2;
  }
  if (maxBlocks<2) {
    printf("Second parameters is maximum number of blocks >=2)\n");
    exit(5);
  } else {
    printf("Allowing at most %d blocks\n",maxBlocks);
  }
  //#define PRESOLVE
#ifndef PRESOLVE
  CoinStructuredModel model((argc<2) ? "../../Data/Netlib/czprob.mps"
                            : argv[1],decompose,maxBlocks);
  if (!model.numberRows())
    exit(10);
  // Get default solver - could change stuff
  ClpSimplex solver;
  // change factorization frequency from 200
  solver.setFactorizationFrequency(100+model.numberRows()/50);
  /*
    This driver does a simple Dantzig Wolfe decomposition
  */
  double time1 = CoinCpuTime() ;
  solver.solve(&model);
  std::cout<<"model took "<<CoinCpuTime()-time1<<" seconds"<<std::endl;
  // Double check
  solver.primal(1);
#else
  ClpSimplex  model;
  int status = model.readMps((argc<2) ? "../../Data/Netlib/czprob.mps"
                             : argv[1]);
  if (status) {
    fprintf(stdout,"Bad readMps %s\n",argv[1]);
    exit(1);
  }
  ClpSimplex * model2=&model;

  CoinStructuredModel modelB;
  modelB.decompose(*model2->matrix(),
                   model2->rowLower(),model2->rowUpper(),
                   model2->columnLower(),model2->columnUpper(),
                   model2->objective(),1,maxBlocks,
                   model2->objectiveOffset());
  // change factorization frequency from 200
  model2->setFactorizationFrequency(100+modelB.numberRows()/50);
  /*
    This driver does a simple Dantzig Wolfe decomposition
  */
  double time1 = CoinCpuTime() ;
  model2->solve(&modelB);
  std::cout<<"model took "<<CoinCpuTime()-time1<<" seconds"<<std::endl;
  // But resolve for safety
  model.primal(1);
#endif
  return 0;
  ClpSimplex solver2;
  solver2.readMps((argc<2) ? "../../Data/Netlib/czprob.mps" : argv[1]);
  time1 = CoinCpuTime() ;
  solver2.dual();
  std::cout<<"second try took "<<CoinCpuTime()-time1<<" seconds"<<std::endl;
  return 0;
}