#include "probfd/algorithms/fret.h"

Inheritance diagram for probfd::algorithms::fret::FRET< typename, typename, typename, typename >:

Description

template<typename, typename, typename, typename>
class probfd::algorithms::fret::FRET< typename, typename, typename, typename >

Implemetation of the Find-Revise-Eliminate-Traps (FRET) framework [9] .

The FRET framework is a framework designed for Generalized Stochastic Shortest-Path Problems (GSSPs, [9]). In this scenario, traditional heuristic search algorithms do not converge against an optimal policy due to the existence of traps. FRET interleaves heuristic searches with a trap elimination procedure until no more traps are found. This guarantees that an optimal policy is returned.

The two common trap elimination strategies find traps in

The greedy value graph of the MDP, or
The greedy policy graph of the optimal policy returned by the last heuristic search

Template Parameters

State	- The state type of the underlying MDP.
Action	- The action type of the underlying MDP.
StateInfoT	- The state info type of the heuristic search algorithm.
GreedyGraphGenerator	- The type of the generator used to construct the search graph in which traps are found and eliminated between heuristic searches.

Public Member Functions
void	print_statistics (std::ostream &out) const override
	Prints algorithm statistics to the specified output stream.

virtual std::unique_ptr< PolicyType >	compute_policy (MDPType &mdp, EvaluatorType &heuristic, param_type< State > state, ProgressReport progress, double maxtime)=0
	Computes a partial policy for the input state.

virtual Interval	solve (MDPType &mdp, EvaluatorType &heuristic, param_type< State > state, ProgressReport progress, double max_time)=0
	Runs the MDP algorithm for the initial state `state` with a maximum time limit.

Member Function Documentation

◆ print_statistics()

template<typename State , typename Action , typename StateInfoT , typename GreedyGraphGenerator >

void probfd::algorithms::fret::FRET< State, Action, StateInfoT, GreedyGraphGenerator >::print_statistics ( std::ostream & ) const

overridevirtual

Prints algorithm statistics to the specified output stream.

Reimplemented from probfd::MDPAlgorithm< State, Action >.

◆ compute_policy()

template<typename State , typename Action >

virtual std::unique_ptr< PolicyType > probfd::MDPAlgorithm< State, Action >::compute_policy	(	MDPType &	mdp,
		EvaluatorType &	heuristic,
		param_type< State >	state,
		ProgressReport	progress,
		double	maxtime )

pure virtualinherited

Computes a partial policy for the input state.

◆ solve()