Back to HomePage.

Usage

Translator

translate.py [DOMAIN] PROBLEM

• DOMAIN (filename): PDDL domain file

• PROBLEM (filename): PDDL problem file

If the domain file is not given, the planner will try to infer a likely name from the problem file name, using the conventions used at the various IPCs. (If in doubt if this will work for you, just try it out.)

Note: Creates a file called output.sas (as well as test.groups, all.groups, ...)

Preprocessor

 preprocess < OUTPUT.SAS

• OUTPUT.SAS (filename): translator output

Note: Creates a file called output

Search component

 downward [OPTIONS] --search SEARCH < OUTPUT

• SEARCH (SearchEngine): configuration of the search algorithm

• OUTPUT (filename): preprocessor output

Options:

• --heuristic HEURISTIC_PREDEFINITION

  • Predefines a heuristic that can afterwards be referenced by the name that is specified in the definition.

• --random-seed SEED

  • Use random seed SEED

Examples

A* search:

   1 # landmark-cut heuristic (previously configuration "ou")
   2  ./downward --search "astar(lmcut())" < ./output
   3 
   4 # merge-and-shrink heuristic with default settings (previously configuration "oa50000")
   5  ./downward --search "astar(mas())" < ./output
   6 
   7 # blind heuristic (previously configuarion "ob")
   8  ./downward --search "astar(blind())" < ./output

Lazy greedy best first search with preferred operators and the queue alternation method:

   1 ## using FF heuristic and context-enhanced additive heuristic (previously: "fFyY")
   2  ./downward --heuristic "hff=ff()" --heuristic "hcea=cea()" \
   3             --search "lazy_greedy(hff, hcea, preferred=(hff, hcea))" \
   4             < ./output
   5 
   6 ## using FF heuristic (previously: "fF")
   7  ./downward --heuristic "hff=ff()" \
   8             --search "lazy_greedy(hff, preferred=(hff))" \
   9             < ./output
  10 
  11 ## using context-enhanced additive heuristic (previously: "yY")
  12  ./downward --heuristic "hcea=cea()" \
  13             --search "lazy_greedy(hcea, preferred=(hcea))" \
  14             < ./output

The above examples use the new best-first search implementation. For comparison, the old best-first search implementation is still available:

 ./downward --heuristic "hff=ff()" --heuristic "hcea=cea()" \
            --search "old_greedy(hff, hcea, preferred=(hff, hcea))" \
            < ./output

If you would like to have another translation from an old-style configuration to the new call-syntax, please add it here as a TODO.

TODO: I would like to see an example that uses the Lama-FF Synergy feature. I'd be most interested in a configuration that is as close to LAMA as currently possible (i.e., using the LAMA and FF heuristics with synergy in a lazy alternation search with preferred operators for both heuristics, using iterated search with the appropriate set of options).

I don't know what iterated search LAMA is performing, but if you describe it in words, I can probably formulate it as a fast downward call. The following would be the call to the old lazy greedy alternation search with LAMA and FF heuristics with synergy, using both heuristics for preferred operators.

 ./downward --heuristic "hlm,hff=lm_ff_syn()" 
            --search "old_greedy(hlm, hff, preferred=(hlm, hff))" 
            < output

This is as close to LAMA as we have right now (same search and heuristics, no caching and no +1 to operator cost):

./downward --heuristic "hlm,hff=lm_ff_syn()"
--search "iterated(
lazy_wastar(hff,hlm,preferred=(hff,hlm),w=10),
lazy_wastar(hff,hlm,preferred=(hff,hlm),w=5),
lazy_wastar(hff,hlm,preferred=(hff,hlm),w=3),
lazy_wastar(hff,hlm,preferred=(hff,hlm),w=2),
lazy_wastar(hff,hlm,preferred=(hff,hlm),w=1),
repeat_last=true)" < output