Program Listing for File modified_fire.cpp

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#include "pele/modified_fire.hpp"
#include <pele/optimizer.hpp>

using std::cout;
using std::vector;

namespace pele {

MODIFIED_FIRE::MODIFIED_FIRE(std::shared_ptr<pele::BasePotential> potential,
                             pele::Array<double> &x0, double dtstart,
                             double dtmax, double maxstep, size_t Nmin,
                             double finc, double fdec, double fa, double astart,
                             double tol, bool stepback, bool save_trajectory,
                             int iterations_before_save,
                             StopCriterionType stop_criterion)
    : ODEBasedOptimizer(potential, x0, tol, save_trajectory,
                        iterations_before_save, stop_criterion),
      _dtstart(dtstart),
      _dt(dtstart),
      _dtmax(dtmax),
      _maxstep(maxstep),
      _Nmin(Nmin),
      _finc(finc),
      _fdec(fdec),
      _fa(fa),
      _astart(astart),
      _a(astart),
      _fold(f_),
      _ifnorm(0),
      _vnorm(0),
      _v(x0.size(), 0),
      _dx(x0.size()),
      _xold(x0.copy()),
      _gold(g_.copy()),
      _fire_iter_number(0),
      _N(x_.size()),
      _stepback(stepback) {
#if PRINT_TO_FILE == 1
  trajectory_file.open("trajectory_modified_fire.txt");
  time_file.open("time_modified_fire.txt");
  gradient_file.open("gradient_modified_fire.txt");
#endif
#if OPTIMIZER_DEBUG_LEVEL > 0
  std::cout << "MODIFIED_FIRE Constructed with parameters:\n";
  std::cout << "dtstart: " << _dtstart << "\n";
  std::cout << "dtmax: " << _dtmax << "\n";
  std::cout << "maxstep: " << _maxstep << "\n";
  std::cout << "Nmin: " << _Nmin << "\n";
  std::cout << "finc: " << _finc << "\n";
  std::cout << "fdec: " << _fdec << "\n";
  std::cout << "fa: " << _fa << "\n";
  std::cout << "astart: " << _astart << "\n";
  std::cout << "tol: " << tol << "\n";
  std::cout << "stepback: " << _stepback << "\n";
#endif
}


void MODIFIED_FIRE::initialize_func_gradient() {
  nfev_ += 1;  // this accounts for the energy evaluation done by the integrator
  f_ = potential_->get_energy_gradient(x_, g_);
  _fold = f_;
  for (size_t k = 0; k < x_.size();
       ++k) {  // set initial velocities (using forward Euler)
    _v[k] = -g_[k] * _dt;
  }
  _ifnorm = 1. / norm(g_);
  _vnorm = norm(_v);
  gradient_norm_ = 1. / (_ifnorm * sqrt(_N));
  func_initialized_ = true;
}

void MODIFIED_FIRE::set_func_gradient(double f, Array<double> grad) {
  if (grad.size() != g_.size()) {
    throw std::invalid_argument("the gradient has the wrong size");
  }
  if (iter_number_ > 0) {
    cout << "warning: setting f and grad after the first iteration.  this is "
            "dangerous.\n";
  }

  // copy the function and gradient
  f_ = f;
  _fold = f_;
  g_.assign(grad);
  for (size_t k = 0; k < x_.size();
       ++k) {  // set initial velocities (using forward Euler)
    _v[k] = -g_[k] * _dt;
  }
  _ifnorm = 1. / norm(g_);
  _vnorm = norm(_v);
  gradient_norm_ = 1. / (_ifnorm * sqrt(_N));
  func_initialized_ = true;
}
}  // namespace pele