problemIO.cpp

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/* $Id: problemIO.cpp 752 2011-08-08 03:45:07Z pbelotti $
 *
 * Name:    problemIO.cpp
 * Author:  Pietro Belotti
 * Purpose: methods of the class CouenneProblem
 *
 * (C) Carnegie-Mellon University, 2006-10.
 * This file is licensed under the Eclipse Public License (EPL)
 */

#include <vector>
#include <fstream>

#include "CoinHelperFunctions.hpp"

#include "CouenneExpression.hpp"
#include "CouenneExprAux.hpp"
#include "CouenneProblem.hpp"
#include "CouenneProblemElem.hpp"

using namespace Couenne;

// output content of the problem
void CouenneProblem::print (std::ostream &out) {

  out << "objectives:" << std::endl;
  for (std::vector <CouenneObjective *>::iterator i = objectives_.begin ();
       i != objectives_.end (); ++i)
    (*i) -> print (out);

  out << "constraints:" << std::endl;
  for (std::vector <CouenneConstraint *>::iterator i = constraints_.begin ();
       i != constraints_.end (); ++i)
    (*i) -> print (out);

  out << "variables:" << std::endl;
  for (std::vector <exprVar *>::iterator i = variables_.begin ();
       i != variables_.end (); ++i)

    if (((*i) -> Type () != AUX) || 
        ((*i) -> Multiplicity () > 0) ||
        (jnlst_ -> ProduceOutput (Ipopt::J_ALL, J_REFORMULATE))) {

      (*i) -> print (out);

      if (((*i) -> Type () == AUX) && 
          (((*i) -> Multiplicity () > 0) ||
           (jnlst_ -> ProduceOutput (Ipopt::J_ALL, J_REFORMULATE)))) {

        out << " (r:" << (*i) -> rank () 
            << ", m:" << (*i) -> Multiplicity () << ") " 
            << (((*i) -> sign () == expression::AUX_EQ)  ? ':' :
                ((*i) -> sign () == expression::AUX_GEQ) ? '>' : 
                ((*i) -> sign () == expression::AUX_LEQ) ? '<' : '?')
            << "= ";// << "<" << (*i) -> Image () << "> ";

        if ((*i) -> Image ())
          (*i) -> Image () -> print (out, false); 
      }

      CouNumber 
        lb = domain_.lb ((*i) -> Index ()),
        ub = domain_.ub ((*i) -> Index ());

      if ((fabs (lb)     < COUENNE_EPS) &&
          (fabs (ub - 1) < COUENNE_EPS) &&
          (*i) -> isInteger ()) out << " binary";
      else {

        out << " [ ";

        if (lb < -COUENNE_INFINITY) out << "-inf"; else out << lb; out << " , ";
        if (ub >  COUENNE_INFINITY) out <<  "inf"; else out << ub; out << " ]";

        if ((*i) -> isInteger ()) out << " integer";
      }

      out << std::endl;
    }

  if (commonexprs_.size ()) {
    out << "common expressions:" << std::endl;
    for (std::vector <expression *>::iterator i = commonexprs_.begin ();
         i != commonexprs_.end (); ++i) {
      out << "v_"    
          << nOrigVars_ - commonexprs_ . size () + i - commonexprs_.begin () << " := ";
      (*i) -> print (out);
      out << std::endl;
    }
  }

  if (optimum_) {
    out << "best known solution: (" << *optimum_;
    for (int i=1; i < nVars (); i++)
      out << ' ' << optimum_ [i];
    out << ')' << std::endl;
  }

  if (fabs (bestObj_) < COUENNE_INFINITY)
    out << "best known objective: " << bestObj_ << std::endl;

  out << "end" << std::endl;
} 


bool CouenneProblem::readOptimum (std::string *fname) {

  FILE *f;

  if (fname == NULL) {

    fname = &problemName_;

    int base = fname -> rfind ('/'), size;
    if (base < 0) base = 0; else base++;

    size = fname -> find  ('.', base) - base;

    char *filename = new char [size+5];
    CoinFillN (filename, size+5, (char) 0);
    fname -> copy (filename, 1+size, base);
    strcat (filename, "txt");
    f = fopen (filename, "r");
    delete [] filename;
  } else f = fopen (fname -> c_str (), "r");

  if (!f) return false;

  optimum_ = (CouNumber *) realloc (optimum_, nVars () * sizeof (CouNumber));

  CoinFillN (optimum_, nVars (), 0.);

  // read optimal objective function first
  if (fscanf (f, "%lf", &bestObj_) < 1) {
    fclose (f);
    printf ("Couenne: warning, could not read objective from file \"%s\"\n", fname -> c_str ());
    return false;
  }

  // read optimal values of variables
  for (int i = 0; i < nOrigVars_; i++)
    if (fscanf (f, "%lf", optimum_ + i) < 1) {
      fclose (f);
      printf ("Couenne: warning, could not read optimal value of x_%d from file \"%s\"\n", i, fname -> c_str ());
      return false;
    } else
      if (variables_ [i] -> isDefinedInteger ()) 
        optimum_ [i] = ceil (optimum_ [i] - .5);

  if (opt_window_ < 1e50) // restrict solution space around known optimum
    for (int i = 0; i < nOrigVars_; i++) {
      Lb (i) = CoinMax (Lb (i), optimum_ [i] - opt_window_ * (1 + fabs (optimum_ [i])));
      Ub (i) = CoinMin (Ub (i), optimum_ [i] + opt_window_ * (1 + fabs (optimum_ [i])));
    }

  // expand solution to auxiliary space
  getAuxs (optimum_);

  fclose (f);
  return true;
}