A landmark graph specification is either a newly created instance or a landmark graph that has been defined previously. This page describes how one can specify a new landmark graph instance. For re-using landmark graphs, see OptionSyntax#Landmark_Predefinitions.

Exhaustive Landmarks

Exhaustively checks for each fact if it is a landmark.This check is done using relaxed planning.

lm_exhaust(cost_type=NORMAL, reasonable_orders=false, only_causal_landmarks=false, disjunctive_landmarks=true, conjunctive_landmarks=true, no_orders=false, lm_cost_type=NORMAL)

• cost_type ({NORMAL, ONE, PLUSONE}): Operator cost adjustment type. No matter what this setting is, axioms will always be considered as actions of cost 0 by the heuristics that treat axioms as actions.

  • NORMAL: all actions are accounted for with their real cost

  • ONE: all actions are accounted for as unit cost

  • PLUSONE: all actions are accounted for as their real cost + 1 (except if all actions have original cost 1, in which case cost 1 is used). This is the behaviour known for the heuristics of the LAMA planner. This is intended to be used by the heuristics, not search engines, but is supported for both.

• reasonable_orders (bool): generate reasonable orders

• only_causal_landmarks (bool): keep only causal landmarks

• disjunctive_landmarks (bool): keep disjunctive landmarks

• conjunctive_landmarks (bool): keep conjunctive landmarks

• no_orders (bool): discard all orderings

• lm_cost_type ({NORMAL, ONE, PLUSONE}): landmark action cost adjustment

Relevant options: reasonable_orders, only_causal_landmarks

Cost types: See OptionCaveats for using cost types with Landmarks

h^m Landmarks

The landmark generation method introduced by Keyder, Richter & Helmert (ECAI 2010).

lm_hm(m=2, cost_type=NORMAL, reasonable_orders=false, only_causal_landmarks=false, disjunctive_landmarks=true, conjunctive_landmarks=true, no_orders=false, lm_cost_type=NORMAL)

• m (int): subset size (if unsure, use the default of 2)

• cost_type ({NORMAL, ONE, PLUSONE}): Operator cost adjustment type. No matter what this setting is, axioms will always be considered as actions of cost 0 by the heuristics that treat axioms as actions.

  • NORMAL: all actions are accounted for with their real cost

  • ONE: all actions are accounted for as unit cost

  • PLUSONE: all actions are accounted for as their real cost + 1 (except if all actions have original cost 1, in which case cost 1 is used). This is the behaviour known for the heuristics of the LAMA planner. This is intended to be used by the heuristics, not search engines, but is supported for both.

• reasonable_orders (bool): generate reasonable orders

• only_causal_landmarks (bool): keep only causal landmarks

• disjunctive_landmarks (bool): keep disjunctive landmarks

• conjunctive_landmarks (bool): keep conjunctive landmarks

• no_orders (bool): discard all orderings

• lm_cost_type ({NORMAL, ONE, PLUSONE}): landmark action cost adjustment

Relevant options: m, reasonable_orders, conjunctive_landmarks, no_orders

Cost types: See OptionCaveats for using cost types with Landmarks

Merged Landmarks

Merges the landmarks and orderings from the parameter landmarks

lm_merged(lm_graphs, cost_type=NORMAL, reasonable_orders=false, only_causal_landmarks=false, disjunctive_landmarks=true, conjunctive_landmarks=true, no_orders=false, lm_cost_type=NORMAL)

• lm_graphs (list of LandmarkGraph):

• cost_type ({NORMAL, ONE, PLUSONE}): Operator cost adjustment type. No matter what this setting is, axioms will always be considered as actions of cost 0 by the heuristics that treat axioms as actions.

  • NORMAL: all actions are accounted for with their real cost

  • ONE: all actions are accounted for as unit cost

  • PLUSONE: all actions are accounted for as their real cost + 1 (except if all actions have original cost 1, in which case cost 1 is used). This is the behaviour known for the heuristics of the LAMA planner. This is intended to be used by the heuristics, not search engines, but is supported for both.

• reasonable_orders (bool): generate reasonable orders

• only_causal_landmarks (bool): keep only causal landmarks

• disjunctive_landmarks (bool): keep disjunctive landmarks

• conjunctive_landmarks (bool): keep conjunctive landmarks

• no_orders (bool): discard all orderings

• lm_cost_type ({NORMAL, ONE, PLUSONE}): landmark action cost adjustment

Precedence: Fact landmarks take precedence over disjunctive landmarks, orderings take precedence in the usual manner (gn > nat > reas > o_reas).

Relevant options: Depends on landmarks

Note: Does not currently support conjunctive landmarks

Cost types: See OptionCaveats for using cost types with Landmarks

RHW Landmarks

The landmark generation method introduced by Richter, Helmert and Westphal (AAAI 2008).

lm_rhw(cost_type=NORMAL, reasonable_orders=false, only_causal_landmarks=false, disjunctive_landmarks=true, conjunctive_landmarks=true, no_orders=false, lm_cost_type=NORMAL)

• cost_type ({NORMAL, ONE, PLUSONE}): Operator cost adjustment type. No matter what this setting is, axioms will always be considered as actions of cost 0 by the heuristics that treat axioms as actions.

  • NORMAL: all actions are accounted for with their real cost

  • ONE: all actions are accounted for as unit cost

  • PLUSONE: all actions are accounted for as their real cost + 1 (except if all actions have original cost 1, in which case cost 1 is used). This is the behaviour known for the heuristics of the LAMA planner. This is intended to be used by the heuristics, not search engines, but is supported for both.

• reasonable_orders (bool): generate reasonable orders

• only_causal_landmarks (bool): keep only causal landmarks

• disjunctive_landmarks (bool): keep disjunctive landmarks

• conjunctive_landmarks (bool): keep conjunctive landmarks

• no_orders (bool): discard all orderings

• lm_cost_type ({NORMAL, ONE, PLUSONE}): landmark action cost adjustment

Relevant Options: reasonable_orders, only_causal_landmarks, disjunctive_landmarks, no_orders

Cost types: See OptionCaveats for using cost types with Landmarks

Zhu/Givan Landmarks

The landmark generation method introduced by Zhu & Givan (ICAPS 2003 Doctoral Consortium).

lm_zg(cost_type=NORMAL, reasonable_orders=false, only_causal_landmarks=false, disjunctive_landmarks=true, conjunctive_landmarks=true, no_orders=false, lm_cost_type=NORMAL)

• cost_type ({NORMAL, ONE, PLUSONE}): Operator cost adjustment type. No matter what this setting is, axioms will always be considered as actions of cost 0 by the heuristics that treat axioms as actions.

  • NORMAL: all actions are accounted for with their real cost

  • ONE: all actions are accounted for as unit cost

  • PLUSONE: all actions are accounted for as their real cost + 1 (except if all actions have original cost 1, in which case cost 1 is used). This is the behaviour known for the heuristics of the LAMA planner. This is intended to be used by the heuristics, not search engines, but is supported for both.

• reasonable_orders (bool): generate reasonable orders

• only_causal_landmarks (bool): keep only causal landmarks

• disjunctive_landmarks (bool): keep disjunctive landmarks

• conjunctive_landmarks (bool): keep conjunctive landmarks

• no_orders (bool): discard all orderings

• lm_cost_type ({NORMAL, ONE, PLUSONE}): landmark action cost adjustment

Relevant options: reasonable_orders, no_orders

Cost types: See OptionCaveats for using cost types with Landmarks

moin code generated by txt2tags 2.6b (http://txt2tags.sf.net) cmdline: txt2tags