// Copyright (C) 2004, 2009 International Business Machines and others.
// All Rights Reserved.
// This code is published under the Eclipse Public License.
//
// $Id: IpLoqoMuOracle.cpp 1861 2010-12-21 21:34:47Z andreasw $
//
// Authors:  Carl Laird, Andreas Waechter     IBM    2004-08-13

#include "IpLoqoMuOracle.hpp"

#ifdef HAVE_CMATH
# include <cmath>
#else
# ifdef HAVE_MATH_H
#  include <math.h>
# else
#  error "don't have header file for math"
# endif
#endif

#ifdef HAVE_CSTDIO
# include <cstdio>
#else
# ifdef HAVE_STDIO_H
#  include <stdio.h>
# else
#  error "don't have header file for stdio"
# endif
#endif

namespace Ipopt
{

#if COIN_IPOPT_VERBOSITY > 0
  static const Index dbg_verbosity = 0;
#endif

  LoqoMuOracle::LoqoMuOracle()
      :
      MuOracle()
  {}

  LoqoMuOracle::~LoqoMuOracle()
  {}

  bool LoqoMuOracle::InitializeImpl(const OptionsList& options,
                                    const std::string& prefix)
  {
    return true;
  }

  bool LoqoMuOracle::CalculateMu(Number mu_min, Number mu_max,
                                 Number& new_mu)
  {
    DBG_START_METH("LoqoMuOracle::CalculateMu",
                   dbg_verbosity);

    Number avrg_compl = IpCq().curr_avrg_compl();
    Jnlst().Printf(J_DETAILED, J_BARRIER_UPDATE,
                   "  Average complemantarity is %lf\n", avrg_compl);

    Number xi = IpCq().curr_centrality_measure();
    Jnlst().Printf(J_DETAILED, J_BARRIER_UPDATE,
                   "  Xi (distance from uniformity) is %lf\n", xi);

    //Number factor = 1.-tau_min_;   //This is the original values
    Number factor = 0.05;   //This is the value I used otherwise
    Number sigma = 0.1*pow(Min(factor*(1.-xi)/xi,2.),3.);

    Number mu = sigma*avrg_compl;
    Jnlst().Printf(J_DETAILED, J_BARRIER_UPDATE,
                   "  Barrier parameter proposed by LOQO rule is %lf\n", mu);

    // DELETEME
    char ssigma[40];
    sprintf(ssigma, " sigma=%8.2e", sigma);
    IpData().Append_info_string(ssigma);
    sprintf(ssigma, " xi=%8.2e ", IpCq().curr_centrality_measure());
    IpData().Append_info_string(ssigma);

    new_mu = Max(Min(mu_max, mu), mu_min);
    return true;
  }

} // namespace Ipopt
