approximationScheme.cpp

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 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
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#include <agrum/base/core/approximations/approximationScheme.h>
 
namespace gum {
 
  ApproximationScheme::ApproximationScheme(bool verbosity) :
      current_state_(ApproximationSchemeSTATE::Undefined), eps_(5e-2), enabled_eps_(true),
      min_rate_eps_(1e-2), enabled_min_rate_eps_(true), max_time_(1.), enabled_max_time_(false),
      max_iter_(static_cast< Size >(10000)), enabled_max_iter_(true),
      burn_in_(static_cast< Size >(0)), period_size_(static_cast< Size >(1)),
      verbosity_(verbosity) {
    GUM_CONSTRUCTOR(ApproximationScheme);
  }
 
  ApproximationScheme::~ApproximationScheme() { GUM_DESTRUCTOR(ApproximationScheme); }
 
  bool ApproximationScheme::continueApproximationScheme(double error) {
    // For coherence, we fix the time used in the method
 
    double timer_step = timer_.step();
 
    if (enabled_max_time_) {
      if (timer_step > max_time_) {
        stopScheme_(ApproximationSchemeSTATE::TimeLimit);
        return false;
      }
    }
 
    if (!startOfPeriod()) { return true; }
 
    if (current_state_ != ApproximationSchemeSTATE::Continue) {
      GUM_ERROR(
          OperationNotAllowed,
          "state of the approximation scheme is not correct : " << messageApproximationScheme());
    }
 
    if (verbosity()) { history_.push_back(error); }
 
    if (enabled_max_iter_) {
      if (current_step_ >= max_iter_) {
        stopScheme_(ApproximationSchemeSTATE::Limit);
        return false;
      }
    }
 
    last_epsilon_    = current_epsilon_;
    current_epsilon_ = error;   // eps rate isEnabled needs it so affectation was
    // moved from eps isEnabled below
 
    if (enabled_eps_) {
      if (current_epsilon_ <= eps_) {
        stopScheme_(ApproximationSchemeSTATE::Epsilon);
        return false;
      }
    }
 
    if (last_epsilon_ >= 0.) {
      if (current_epsilon_ > .0) {
        // ! current_epsilon_ can be 0. AND epsilon
        // isEnabled can be disabled !
        current_rate_ = std::fabs((current_epsilon_ - last_epsilon_) / current_epsilon_);
      }
      // limit with current eps ---> 0 is | 1 - ( last_eps / 0 ) | --->
      // infinity the else means a return false if we isEnabled the rate below,
      // as we would have returned false if epsilon isEnabled was enabled
      else {
        current_rate_ = min_rate_eps_;
      }
 
      if (enabled_min_rate_eps_) {
        if (current_rate_ <= min_rate_eps_) {
          stopScheme_(ApproximationSchemeSTATE::Rate);
          return false;
        }
      }
    }
 
    if (stateApproximationScheme() == ApproximationSchemeSTATE::Continue) {
      if (onProgress.hasListener()) {
        GUM_EMIT3(onProgress, current_step_, current_epsilon_, timer_step);
      }
 
      return true;
    } else {
      return false;
    }
  }
}   // namespace gum
 
#ifdef GUM_NO_INLINE
#  include <agrum/base/core/approximations/approximationScheme_inl.h>
#endif