# -*- coding: utf-8 -*-
"""
Copyright Sylvain Bouveret, Yann Chevaleyre and François Durand
sylvain.bouveret@imag.fr, yann.chevaleyre@dauphine.fr, fradurand@gmail.com
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
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Whalrus 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 Whalrus. If not, see <http://www.gnu.org/licenses/>.
"""
from whalrus.scales.scale_range import ScaleRange
from whalrus.scorers.scorer import Scorer
from whalrus.scorers.scorer_levels import ScorerLevels
from whalrus.ballots.ballot_levels import BallotLevels
from whalrus.rules.rule_score_num_average import RuleScoreNumAverage
from whalrus.converters_ballot.converter_ballot_to_grades import ConverterBallotToGrades
from whalrus.converters_ballot.converter_ballot import ConverterBallot
[docs]class RuleRangeVoting(RuleScoreNumAverage):
"""
Range voting.
Parameters
----------
args
Cf. parent class.
converter : ConverterBallot
Default: :class:`ConverterBallotToGrades`.
scorer : Scorer
Default: :class:`ScorerLevels`.
kwargs
Cf. parent class.
Examples
--------
Typical usage:
>>> RuleRangeVoting([{'a': 1, 'b': .8, 'c': .2}, {'a': 0, 'b': .6, 'c': 1}]).scores_
{'a': Fraction(1, 2), 'b': Fraction(7, 10), 'c': Fraction(3, 5)}
>>> RuleRangeVoting([{'a': 10, 'b': 8, 'c': 2}, {'a': 0, 'b': 6, 'c': 10}]).scores_
{'a': 5, 'b': 7, 'c': 6}
The following examples use the ballot converter:
>>> RuleRangeVoting(['a > b > c']).profile_converted_[0].as_dict
{'a': 1, 'b': Fraction(1, 2), 'c': 0}
>>> RuleRangeVoting(
... ['a > b > c'], converter=ConverterBallotToGrades(scale=ScaleRange(0, 10))
... ).profile_converted_[0].as_dict
{'a': 10, 'b': 5, 'c': 0}
To examine the effect of the options, let us examine:
>>> b1 = BallotLevels({'a': 8, 'b': 10}, candidates={'a', 'b'})
>>> b2 = BallotLevels({'a': 6, 'c': 10}, candidates={'a', 'b', 'c'})
In ballot ``b1``, candidate `c` is absent, which means that the candidate was not even available when the voter
cast her ballot. In ballot ``b2``, candidate `b` is ungraded: it was available, but the voter decided not to give
it a grade. By the way, we will also introduce a candidate `d` who receives no evaluation at all. Here are several
possible settings for the voting rule, along with their consequences:
>>> RuleRangeVoting([b1, b2], candidates={'a', 'b', 'c', 'd'}).scores_
{'a': 7, 'b': 10, 'c': 10, 'd': 0}
>>> RuleRangeVoting([b1, b2], candidates={'a', 'b', 'c', 'd'}, default_average=5).scores_
{'a': 7, 'b': 10, 'c': 10, 'd': 5}
>>> RuleRangeVoting([b1, b2], candidates={'a', 'b', 'c', 'd'},
... scorer=ScorerLevels(level_ungraded=0)).scores_
{'a': 7, 'b': 5, 'c': 10, 'd': 0}
>>> RuleRangeVoting([b1, b2], candidates={'a', 'b', 'c', 'd'},
... scorer=ScorerLevels(level_ungraded=0, level_absent=0)).scores_
{'a': 7, 'b': 5, 'c': 5, 'd': 0}
For more information, cf. :class:`ScorerLevels`.
"""
def __init__(self, *args, converter: ConverterBallot = None, scorer: Scorer = None, **kwargs):
if converter is None:
converter = ConverterBallotToGrades()
if scorer is None:
scorer = ScorerLevels()
super().__init__(*args, converter=converter, scorer=scorer, **kwargs)