void Mocasinns::Metropolis<ConfigurationType,Step,RandomNumberGenerator,rejection_free>::do_metropolis_simulation(const TemperatureType& beta, Accumulator& measurement_accumulator)
{
// Check the concept of the observator
BOOST_CONCEPT_ASSERT((Concepts::ObservatorConcept<Observator,ConfigurationType>));
// Check the concept of the observable
BOOST_CONCEPT_ASSERT((Concepts::ObservableConcept<typename Observator::observable_type>));
// Check the concept of the accumulator
BOOST_CONCEPT_ASSERT((Concepts::AccumulatorConcept<Accumulator, typename Observator::observable_type>));
// Log the start of the simulation
this->simulation_start_log();
// Perform the relaxation steps
do_metropolis_steps(simulation_parameters.relaxation_steps, beta);
// For each measurement, perform the steps, invoke the signal handler, take the measurement and check for posix signals
for (unsigned int m = 0; m < simulation_parameters.measurement_number; ++m)
{
// Do the steps
do_metropolis_steps(simulation_parameters.steps_between_measurement, beta);
// Call the measurement signal handler
signal_handler_measurement(this);
// Observe and check for posix signals
measurement_accumulator(Observator::observe(this->configuration_space));
if (this->check_for_posix_signal()) return;
}
}
std::vector<typename Observator::observable_type> Metropolis<ConfigurationType, Step, RandomNumberGenerator>::autocorrelation_function(const TemperatureType& beta, unsigned int maximal_time, unsigned int simulation_time_factor)
{
// Check the concept of the observator
BOOST_CONCEPT_ASSERT((Concepts::ObservatorConcept<Observator,ConfigurationType>));
// Check the concept of the observable
BOOST_CONCEPT_ASSERT((Concepts::ObservableConcept<typename Observator::observable_type>));
// Do the relaxation steps
do_metropolis_steps(simulation_parameters.relaxation_steps, beta);
// Define the vector with the results
std::vector<typename Observator::observable_type> results;
// Define the vector with the measurments of the observable and take the measurements
std::vector<typename Observator::observable_type> observable_measurements;
for (unsigned int i = 0; i <= maximal_time*simulation_time_factor; ++i)
{
do_metropolis_steps(this->get_config_space()->system_size(), beta);
observable_measurements.push_back(Observator::observe(this->get_config_space()));
}
// Define an accumulator and calculate the mean value of the observable
ba::accumulator_set<typename Observator::observable_type, ba::stats<ba::tag::mean> > acc_measured_mean(observable_measurements[0]);
for (unsigned int i = 0; i <= maximal_time*simulation_time_factor; ++i)
{
acc_measured_mean(observable_measurements[i]);
}
typename Observator::observable_type measured_mean = ba::mean(acc_measured_mean);
// Calculate the autocorrelation function using an accumulator
for (unsigned int time = 0; time <= maximal_time; ++time)
{
// Calculate the mean autocorrelation function for time
ba::accumulator_set<typename Observator::observable_type, ba::stats<ba::tag::mean> > acc_autocorrelation_function_time(observable_measurements[0]);
for (unsigned int sweep = 0; sweep < simulation_time_factor; ++sweep)
{
unsigned int start_time = sweep*maximal_time;
acc_autocorrelation_function_time(observable_measurements[start_time]*observable_measurements[start_time + time]);
}
// Add to the result vector
results.push_back(ba::mean(acc_autocorrelation_function_time) - measured_mean*measured_mean);
}
// Return the result vector
return results;
}