Source code for whalrus.rules.rule_baldwin

# -*- coding: utf-8 -*-
Copyright Sylvain Bouveret, Yann Chevaleyre and Fran├žois Durand,,

This file is part of Whalrus.

Whalrus is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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from whalrus.rules.rule import Rule
from whalrus.rules.rule_iterated_elimination import RuleIteratedElimination
from whalrus.rules.rule_borda import RuleBorda
from whalrus.eliminations.elimination import Elimination
from whalrus.eliminations.elimination_last import EliminationLast

[docs]class RuleBaldwin(RuleIteratedElimination): """ Baldwin's rule. At each round, the candidate with the lowest Borda score is eliminated. Parameters ---------- args Cf. parent class. base_rule : Rule Default: :class:`RuleBorda`. elimination : Elimination Default: :class:`EliminationLast` with ``k=1``. kwargs Cf. parent class. Examples -------- >>> rule = RuleBaldwin(['a > b > c', 'a > b ~ c']) >>> rule.eliminations_[0].rule_.gross_scores_ {'a': 4, 'b': Fraction(3, 2), 'c': Fraction(1, 2)} >>> rule.eliminations_[1].rule_.gross_scores_ {'a': 2, 'b': 0} >>> rule.eliminations_[2].rule_.gross_scores_ {'a': 0} >>> rule.winner_ 'a' """ def __init__(self, *args, base_rule: Rule = None, elimination: Elimination = None, **kwargs): if base_rule is None: base_rule = RuleBorda() if elimination is None: elimination = EliminationLast(k=1) super().__init__(*args, base_rule=base_rule, elimination=elimination, **kwargs)