Probabilistic Fast Downward (probFD) is an extension of the Fast Downward planning system (release 23.06) for fully observable probabilistic planning domains.
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The problem description language assumed by probFD is PPDDL.
probFD supports a variety of different search algorithms for Generalized Stochastic Shortest-Path Problems (GSSPs), for example:
- Topological Value Iteration
- i-Dual and i²-Dual
- Labelled real-time dynamic programming (LRTDP)
- Improved LAO* (iLAO*)
To handle zero-reward cycles, probFD implements both end component decomposition and the FRET framework to eliminate these cycles and to guarantee convergence of the algorithms against the optimal value function. As a special case in the GSSP framework, probFD also supports MaxProb analysis.
The planner currently implements the following families of heuristics:
- Determinization-based heuristics by usage of a classical heuristic on the all-outcomes determinization.
- Occupation measure heuristics: The regrouped operator counting heuristic hroc and the projection occupation measure heuristic hpom
- Pattern database heuristics for SSPs. Multiple pattern generators are supported, including classical pattern generators that operator on the all-outcomes determinization, as well as adaptations of the CEGAR and hillclimbing pattern generation algorithms for probabilistic planning tasks. Notably also supports unavoidable dead-ends and zero-reward cycles.
See build instructions for details.
The following list includes all people that actively contributed to Probabilistic Fast Downward.
- 2019-2022 Marcel Steinmetz
- 2019-2022 Thorsten Klößner
- 2022 Thomas Keller
Fast Downward is a domain-independent classical planning system.
Copyright 2003-2023 Fast Downward contributors (see below).
For further information:
- Fast Downward website: https://www.fast-downward.org
- Report a bug or file an issue: https://issues.fast-downward.org
- Fast Downward mailing list: https://groups.google.com/forum/#!forum/fast-downward
- Fast Downward main repository: https://github.com/aibasel/downward
This version of Fast Downward has been tested with the following software versions:
| OS | Python | C++ compiler | CMake |
|---|---|---|---|
| Ubuntu 22.04 | 3.10 | GCC 11, GCC 12, Clang 14 | 3.22 |
| Ubuntu 20.04 | 3.8 | GCC 10, Clang 12 | 3.16 |
| macOS 12 | 3.10 | AppleClang 14 | 3.24 |
| macOS 11 | 3.8 | AppleClang 13 | 3.24 |
| Windows 10 | 3.8 | Visual Studio Enterprise 2019 (MSVC 19.29) and 2022 (MSVC 19.31) | 3.22 |
We test LP support with CPLEX 22.1.1 and SoPlex 6.0.3+. On Ubuntu we test both CPLEX and SoPlex. On Windows we currently only test CPLEX, and on macOS we do not test LP solvers (yet).
The following list includes all people that actively contributed to Fast Downward, i.e., all people that appear in some commits in Fast Downward's history (see below for a history on how Fast Downward emerged) or people that influenced the development of such commits. Currently, this list is sorted by the last year the person has been active, and in case of ties, by the earliest year the person started contributing, and finally by last name.
- 2003-2023 Malte Helmert
- 2008-2016, 2018-2023 Gabriele Roeger
- 2010-2023 Jendrik Seipp
- 2010-2011, 2013-2023 Silvan Sievers
- 2012-2023 Florian Pommerening
- 2013, 2015-2023 Salomé Eriksson
- 2015, 2021-2023 Thomas Keller
- 2018-2023 Patrick Ferber
- 2018-2020, 2023 Augusto B. Corrêa
- 2021-2023 Clemens Büchner
- 2022-2023 Remo Christen
- 2023 Simon Dold
- 2023 Claudia S. Grundke
- 2023 Emanuele Tirendi
- 2021-2022 Dominik Drexler
- 2016-2020 Cedric Geissmann
- 2017-2020 Guillem Francès
- 2020 Rik de Graaff
- 2015-2019 Manuel Heusner
- 2017 Daniel Killenberger
- 2016 Yusra Alkhazraji
- 2016 Martin Wehrle
- 2014-2015 Patrick von Reth
- 2009-2014 Erez Karpas
- 2014 Robert P. Goldman
- 2010-2012 Andrew Coles
- 2010, 2012 Patrik Haslum
- 2003-2011 Silvia Richter
- 2009-2011 Emil Keyder
- 2010-2011 Moritz Gronbach
- 2010-2011 Manuela Ortlieb
- 2011 Vidal Alcázar Saiz
- 2011 Michael Katz
- 2011 Raz Nissim
- 2010 Moritz Goebelbecker
- 2007-2009 Matthias Westphal
- 2009 Christian Muise
The current version of Fast Downward is the merger of three different projects:
- the original version of Fast Downward developed by Malte Helmert and Silvia Richter
- LAMA, developed by Silvia Richter and Matthias Westphal based on the original Fast Downward
- FD-Tech, a modified version of Fast Downward developed by Erez Karpas and Michael Katz based on the original code
In addition to these three main sources, the codebase incorporates code and features from numerous branches of the Fast Downward codebase developed for various research papers. The main contributors to these branches are Malte Helmert, Gabi Röger and Silvia Richter.
Fast Downward is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
Fast Downward is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.