Tie-Breaking

Tie-Breaking#

exception TieBreakingException[source]#

Raised when a tie occurs and no tie-breaking rule is provided.

class TieBreakingRule(func: Callable[[AbstractTrichotomousProfile, Alternative], int | float | mpq])[source]#

Implements a tie-breaking rule.

Parameters:

func (Callable[[TrichotomousProfile, Alternative], Numeric]) – A function taking as input an instance, a profile and a project and returning the value on which the project will be sorted.

func#

A function taking as input an instance, a profile and a project and returning the value on which the project will be sorted.

Type:

Callable[[TrichotomousProfile, Alternative], Numeric]

order(profile: AbstractTrichotomousProfile, alternatives: Iterable, key: Callable[[...], Alternative] | None = None) → list[Alternative][source]#

Break the ties among all the alternatives provided in input and returns them ordered.

Parameters:

  • profile (TrichotomousProfile) – The profile.

  • alternatives (Iterable) – The set of alternatives between which ties are to be broken.

  • key (Callable[..., Alternative], optional) – A key function to select the value associated with each alternative, passed as the key argument of the sorted function. Defaults to lambda x: x.

Returns:

The alternatives, ordered by the tie-breaking rule.

Return type:

list[Alternative]

untie(profile: AbstractTrichotomousProfile, alternatives: Iterable, key: Callable[[...], Alternative] | None = None) → Alternative[source]#

Break the ties among all the alternatives provided in input and returns a single one of them. Orders the alternatives according to the tie-breaking rule and return the first element of the order.

Parameters:

  • profile (TrichotomousProfile) – The profile.

  • alternatives (Iterable) – The set of alternatives between which ties are to be broken.

  • key (Callable[..., Alternative], optional) – A key function to select the value associated with each alternative, passed as the key argument of the sorted function. Defaults to lambda x: x.

Returns:

The first alternative according to the tie-breaking order.

Return type:

Alternative

app_score_tie_breaking = <trivoting.tiebreaking.TieBreakingRule object>#

Implements tie breaking based on the approval score where the projects with the highest approval score in the profile is selected.

lexico_tie_breaking = <trivoting.tiebreaking.TieBreakingRule object>#

Implements lexicographic tie breaking, i.e., tie-breaking based on the name of the alternatives.

refuse_tie_breaking = <trivoting.tiebreaking.TieBreakingRule object>[source]#

Special tie-breaking function that simply raises an error when a tie needs to be broken.

support_tie_breaking = <trivoting.tiebreaking.TieBreakingRule object>#

Implements tie breaking based on the support where the projects with the highest support in the profile is selected.

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