preflibtools.properties.subdomains.dichotomous
Module for testing whether dichotomous instances are part of some subdomains.
Partition Subdomains
- is_2_part(instance)
Tests whether the given categorical instance is 2 partitions.
- Parameters
instance (CategoricalInstance) – the instance
- Returns
A tuple consisting of a boolean indicating if the instance is 2 partitions and a partition of the candidates into two sets (or None if the instance is not 2 partitions).
- Return type
tuple[bool, list[set] | None]
- is_part(instance)
Tests whether the given categorical instance is part of the partition subdomain.
- Parameters
instance (CategoricalInstance) – the instance
- Returns
A tuple consisting of a boolean indicating if the instance is partition and a partition of the candidates into sets (or None if the instance is not partition).
- Return type
tuple[bool, list[set] | None]
Interval Subdomains
- instance_to_ci_matrix(instance)
Builds a matrix so that the instance is candidate interval if and only if the matrix has the consecutive ones property.
- Parameters
instance (CategoricalInstance) – the instance, only the first class is used
- is_candidate_extremal_interval(instance)
Tests whether the given categorical instance is candidate extremal interval.
- Parameters
instance (CategoricalInstance) – the instance
- Returns
A tuple consisting of a boolean indicating if the instance is candidate extremal interval and the ordering of the candidates (or None if the instance is not candidate extremal interval).
- Return type
tuple[bool, list | None]
- is_candidate_interval(instance)
Tests whether the given categorical instance is candidate interval.
- Parameters
instance (CategoricalInstance) – the instance
- Returns
A tuple consisting of a boolean indicating if the instance is candidate interval and the ordering of the candidates (or None if the instance is not candidate interval).
- Return type
tuple[bool, list | None]
- is_voter_extremal_interval(instance)
Tests whether the given categorical instance is voter extremal interval.
- Parameters
instance (CategoricalInstance) – the instance
- Returns
A tuple consisting of a boolean indicating if the instance is voter extremal interval and the ordering of the voters (or None if the instance is not voter extremal interval).
- Return type
tuple[bool, list | None]
- is_voter_interval(instance)
Tests whether the given categorical instance is voter interval.
- Parameters
instance (CategoricalInstance) – the instance
- Returns
A tuple consisting of a boolean indicating if the instance is voter interval and the ordering of the voters (or None if the instance is not voter interval).
- Return type
tuple[bool, list | None]
Euclidean Subdomains
- is_dichotomous_euclidean(instance)
Tests whether the given categorical instance representing dichotomous preferences is Euclidean.
- Parameters
instance (CategoricalInstance) – the instance
- Returns
A tuple consisting of a boolean indicating if the instance is Euclidean, a dictionary mapping voters to their position and radius, and a dictionnary mapping alternatives to their position (or None if the instance is not Euclidean).
- Return type
tuple[bool, list | None, list | None]
Single-Crossing Subdomains
- is_weakly_single_crossing(instance)
Tests whether the given categorical instance is weakly single crossing. Transforms a categorical instance into a matrix as defined in the proof of Theorem 13 in https://martin.lackner.xyz/publications/incompletesc-full.pdf and checks whether the matrix has the consecutive ones property.
- Parameters
instance (CategoricalInstance) – the instance
- Returns
A tuple consisting of a boolean indicating if the instance is weakly single crossing and an ordering of the ballots (or None if the instance is not weakly single crossing).
- Return type
tuple[bool, list[set] | None]