paradiseo/problems/eval/ubqpEval.h

/*
<ubqpEval.h>
Copyright (C) DOLPHIN Project-Team, INRIA Lille - Nord Europe, 2006-2010

Sebastien Verel

This software is governed by the CeCILL license under French law and
abiding by the rules of distribution of free software.  You can  ue,
modify and/ or redistribute the software under the terms of the CeCILL
license as circulated by CEA, CNRS and INRIA at the following URL
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*/

#ifndef _ubqpEval_h
#define _ubqpEval_h

#include <vector>
#include <eoEvalFunc.h>

/**
 * Full evaluation Function 
 * for unconstrainted binary quadratic programming problem
 */
template< class EOT >
class UbqpEval : public eoEvalFunc<EOT>
{
public:

  /**
   * Constructor
   * instance is given in the ORLIB format (0) or matrix format (1): 
   * The format of these data files is:
   * number of test problem in the serie
   * for each test problem in turn:
   *    - Format 0:
   *         number of variables (n), number of non-zero elements in the q(i,j) matrix
   *           for each non-zero element in turn: 
   *           i, j, q(i,j) {=q(j,i) as the matrix is symmetric}
   *    - Format 1:
   *         number of variables (n)
   *           for each line i
   *               for each columm j
   *                   q(i,j)
   * @param _fileName file name of the instance in ORLIB format
   * @param format id of the file format (0 or 1)
   * @param _numInstance the number of the given instance to solve
   */
  UbqpEval(std::string & _fileName, unsigned format = 0, unsigned int _numInstance = 0) {
    std::fstream file(_fileName.c_str(), std::ios::in);

    if (!file) {
      std::string str = "UbqpEval: Could not open file [" + _fileName + "]." ;
      throw std::runtime_error(str);
    }

    unsigned int nbInstances;
    file >> nbInstances;

    // number of non zero in the matrix
    unsigned int nbNonZero = 0;

    unsigned int i, j;
    int v;

    for(unsigned k = 0; k < _numInstance; k++) {
      if (format == 0) {
	file >> nbVar >> nbNonZero ;

	for(unsigned kk = 0; kk < nbNonZero; kk++)
	  file >> i >> j >> v;
      } else {
	file >> nbVar ;

	for(unsigned int i = 0; i < nbVar; i++) {
	  for(unsigned int j = 0; j < nbVar; j++) {
	    file >> v;
	  }
	}
      }

    }

    // the chosen instance
    if (format == 0)
      file >> nbVar >> nbNonZero ;
    else
      file >> nbVar ;

    // creation of the matrix
    Q = new int*[nbVar];

    for(unsigned int i = 0; i < nbVar; i++) {
      Q[i] = new int[nbVar];
      for(unsigned int j = 0; j < nbVar; j++)
	Q[i][j] = 0;
    }

    // read the matrix
    if (format == 0) {
      for(unsigned int k = 0; k < nbNonZero; k++) {
	file >> i >> j >> v;
	if (i > 0 && j > 0)
	  Q[i - 1][j - 1] = v;
	else {
	  std::string str = "UbqpEval: some indices are 0 in the instance file (in format 0), please check." ;
	  throw std::runtime_error(str);
	}
      }
    } else {
      for(unsigned int i = 0; i < nbVar; i++) {
	for(unsigned int j = 0; j < nbVar; j++) {
	  file >> v;
	  Q[i][j] = v;
	}
      }
    }
    
    file.close();

    // put the matrix in lower triangular form
    for(unsigned i = 1; i < nbVar; i++)
      for(unsigned int j = 0; j < i; j++) {
	Q[i][j] = Q[i][j] + Q[j][i];
	Q[j][i] = 0;
      }

  }

  /**
   * Destructor
   */
  ~UbqpEval() {
    if (Q != NULL) {
      for(unsigned i = 0; i < nbVar; i++)
	delete[] Q[i];

      // delete the matrix
      delete[] Q;
    }
  }

  /**
   * fitness evaluation of the solution
   *
   * @param _solution the solution to evaluation
   */
  virtual void operator()(EOT & _solution) {
    int fit = 0;
    unsigned int j;

    for(unsigned i = 0; i < nbVar; i++)
      if (_solution[i] == 1) 
	for(j = 0; j <= i; j++)
	  if (_solution[j] == 1) 
	    fit += Q[i][j];
	  
    _solution.fitness(fit);
  }

  /*
   * to get the matrix Q
   *
   * @return matrix Q
   */
  int** getQ() {
    return Q;
  }

  /*
   * to get the number of variable (bit string length)
   *
   * @return bit string length
   */
  int getNbVar() {
    return nbVar;
  }

  void print() {
    std::cout << nbVar << std::endl;
    for(unsigned int i = 0; i < nbVar; i++) {
      for(unsigned int j = 0; j < nbVar; j++) {
	std::cout << Q[i][j] << " ";
      }
      std::cout << std::endl;
    }
  }

private:
  /**
   * variables (used in incremental evaluation)
   */

  // number of variable
  unsigned int nbVar; 

  // matrix of flux:
  //   the matrix is put in lower triangular form: for i<j Q[i][j] = 0
  int ** Q;
};

#endif