Counterfactual regret minimization of two-player zero-sum incomplete-information games in rust. This is a rust library and binary for computing approximate nash-equilibria of two-player zero-sum incomplete-information games.
To use the library part of this crate, add the following to your Cargo.toml.
toml
[dependencies]
cfr = "0.0.1"
Then implement TerminalNode, ChanceNode, and PlayerNode for your relevant
objects in the game tree.
Finally execute:
rust
use cfr::{Game, Solution};
let game = Game::from_node(...)?;
let Solution {regret, strategy} = game.solve();
let named = game.name_strategy(&strategy)?;
This package can also be used as a binary utilizing json format. To use first install it with
bash
$ cargo install cfr --features=binary
Game trees are defined using a JSON domain specific language that should be
passed in via stdin. The resulting strategy for each player in addition to
information about the strategy pair will be written to stdout.
bash
$ cfr < game.json
{
"expected_utility": 0.05555555727916178,
"player_one_regret": 1.186075528125663e-06,
"player_two_regret": 8.061797025377127e-05,
"regret": 8.061797025377127e-05,
"player_one_strategy": { ... },
"player_two_regret": { ... }
}
The DSL is defined by:
bison
node ::= terminal || chance || player
terminal ::= { "terminal": <number> }
chance ::= { "chance": { "<named outcome>": { "prob": <number>, "state": node }, ... } }
player ::= { "player": { "player_one": <bool>, "infoset": <string>, "actions": { "<named action>": node, ... } } }
A minimal example highlighting all types of nodes, but of an uninteresting game is:
json
{
"chance": {
"single": {
"prob": 1.0,
"state": {
"player": {
"player_one": true,
"infoset": "none",
"actions": {
"only": {
"terminal": 0.0
}
}
}
}
}
}
}
In this game there's a 100% chance of the "single" outcome, followed by a
move by player one where they have information "none" and only have one
action: "only". After selecting that action, they get payoff 0.
This error occurs when the json doesn't match the expected format for reading. See binary for details on the specification, and make sure that the json you're providing matches that specification.
This error occurs if there were problems with the game specification that made creating a compact game impossible. There are two different ways this could fail, and all will come with extra information:
ChanceNotProbability : This gets thrown if there's a chance node who's
total probability between all outcomes isn't one.ActionsNotEqual : This gets thrown if two different states with the same
information sets had different actions available to them. It will report what
information set, player, and actions caused the error.