nfgalleq.cc

Gambit 是一个游戏库理论软件

//
// $Source: /home/gambit/CVS/gambit/sources/nash/nfgalleq.cc,v $
// $Date: 2002/08/27 18:29:40 $
// $Revision: 1.4 $
//
// DESCRIPTION:
// Enumerates all Nash equilibria in a normal form game, via solving
// systems of polynomial equations
//
// This file is part of Gambit
// Copyright (c) 2002, The Gambit Project
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//

#include "game/nfgensup.h"
#include "nfgalleq.h"
#include "polenum.h"

nfgPolEnum::nfgPolEnum(void)
  : m_stopAfter(0)
{ }

gList<MixedSolution> nfgPolEnum::Solve(const NFSupport &p_support,
				       gStatus &p_status)
{
  p_status.SetProgress(0.0);
  p_status << "Step 1 of 2: Enumerating supports";
  gList<const NFSupport> supports = PossibleNashSubsupports(p_support,
							    p_status);

  p_status.SetProgress(0.0);
  p_status << "Step 2 of 2: Computing equilibria";

  gList<const NFSupport> singularSupports;
  gList<MixedSolution> solutions;

  for (int i = 1; (i <= supports.Length() &&
		   (m_stopAfter == 0 || m_stopAfter > solutions.Length())); 
       i++) {
    p_status.Get();
    p_status.SetProgress((double) (i-1) / (double) supports.Length());
    long newevals = 0;
    double newtime = 0.0;
    gList<MixedSolution> newsolns;
    bool is_singular = false;
    
    PolEnumParams params;
    params.stopAfter = 0;
    PolEnum(supports[i], params, newsolns, p_status,
	    newevals, newtime, is_singular);

    for (int j = 1; j <= newsolns.Length(); j++) {
      if (newsolns[j].IsNash()) {
	solutions += newsolns[j];
      }
    }

    if (is_singular) { 
      singularSupports += supports[i];
    }
  }

  return solutions;
}