mcpele: adaptive_takestep.cpp Source File

00001 #include "mcpele/adaptive_takestep.h"
00002 
00003 namespace mcpele {
00004 
00005 AdaptiveTakeStep::AdaptiveTakeStep(std::shared_ptr<TakeStep> ts,
00006         const size_t interval, const double factor,
00007         const double min_acceptance_ratio, const double max_acceptance_ratio)
00008     : m_ts(ts),
00009       m_interval(interval),
00010       m_total_steps(0),
00011       m_accepted_steps(0),
00012       m_factor(factor),
00013       m_min_acceptance_ratio(min_acceptance_ratio),
00014       m_max_acceptance_ratio(max_acceptance_ratio)
00015 {
00016     if (factor <= 0 || factor >= 1) {
00017         throw std::runtime_error("AdaptiveTakeStep::AdaptiveTakeStep: input factor has illegal value");
00018     }
00019 }
00020 
00021 void AdaptiveTakeStep::report(pele::Array<double>&, const double,
00022         pele::Array<double>&, const double, const bool success, MC* mc)
00023 {
00024     ++m_total_steps;
00025     if (success) {
00026         ++m_accepted_steps;
00027     }
00028     if (mc->get_iterations_count() % m_interval == 0) {
00029         const double acceptance_fraction = static_cast<double>(m_accepted_steps) / static_cast<double>(m_total_steps);
00030         m_accepted_steps = 0;
00031         m_total_steps = 0;
00032         if (acceptance_fraction < get_min_acceptance_ratio()) {
00033             m_ts->increase_acceptance(m_factor);
00034         }
00035         else if (acceptance_fraction > get_max_acceptance_ratio()) {
00036             m_ts->decrease_acceptance(m_factor);
00037         }
00038     }
00039 }
00040 
00041 } // namespace mcpele