adaptive_takestep.cpp

#include "mcpele/adaptive_takestep.h"

namespace mcpele {

AdaptiveTakeStep::AdaptiveTakeStep(std::shared_ptr<TakeStep> ts,
        const size_t interval, const double factor,
        const double min_acceptance_ratio, const double max_acceptance_ratio)
    : m_ts(ts),
      m_interval(interval),
      m_total_steps(0),
      m_accepted_steps(0),
      m_factor(factor),
      m_min_acceptance_ratio(min_acceptance_ratio),
      m_max_acceptance_ratio(max_acceptance_ratio)
{
    if (factor <= 0 || factor >= 1) {
        throw std::runtime_error("AdaptiveTakeStep::AdaptiveTakeStep: input factor has illegal value");
    }
}

void AdaptiveTakeStep::report(pele::Array<double>&, const double,
        pele::Array<double>&, const double, const bool success, MC* mc)
{
    ++m_total_steps;
    if (success) {
        ++m_accepted_steps;
    }
    if (mc->get_iterations_count() % m_interval == 0) {
        const double acceptance_fraction = static_cast<double>(m_accepted_steps) / static_cast<double>(m_total_steps);
        m_accepted_steps = 0;
        m_total_steps = 0;
        if (acceptance_fraction < get_min_acceptance_ratio()) {
            m_ts->increase_acceptance(m_factor);
        }
        else if (acceptance_fraction > get_max_acceptance_ratio()) {
            m_ts->decrease_acceptance(m_factor);
        }
    }
}

} // namespace mcpele