Releases: mggg/VoteKit
v2.0.0
This update will break some of the backwards compatibility, so we have incremented the major version number.
Added
- A
PreferenceInterval
class. - MCMC sampling for both
BradleyTerry
ballot generators. - Add print statement to
BallotGraph
so that when you draw the graph without labels, it prints a dictionary of candidate labels for you. - Add an IRV election class, which is just a wrapper for STV with 1 seat.
- Add default option to Borda election class, so users do not have to input a score vector if they want to use the traditional Borda vector.
- Add several methods to
PairwiseComparisonGraph
. Added two boolean methods that return True if there is a condorcet winner or if there is a condorcet cycle. Added two get methods that return the winner or the cycles. Cached the results ofdominating_tiers
andget_condorcet_cycles
. - Added optional to_float method to
first_place_votes
if users want to see them as floats instead of Fractions.
-Added aby_bloc
parameter togenerate_profile
. If True, this returns a tuple, the first entry of which is a dictionary of PreferenceProfiles by bloc. The second entry is the aggregated profile. This is very helpful for analyzing the behavior of a single bloc of voters. Defaults to False for backwards compatibility. - Created a
Cumulative
ballot generator class. TheCumulative
class works like PL, but samples with replacement instead of without. The ranking order does not matter here, simply that candidates are listed on the ballot with multiplicity. - Created a
HighestScore
election class. This takes in a profile and a score vector, and returns the candidates with highest scores. There is a lot of flexibility in the score vector, so this class can run things like Borda, cumulative, etc. - Created a
Cumulative
election class which is just a subclass ofHighestScore
with the score vector set to all 1s. Thus anyone appearing on the ballot gets one point for each time they appear. - Wrote an
__add__
method forPreferenceProfile
that combines the ballot lists of two profiles. - Created utility functions to compute the winners of a profile given a score vector, as well as to validate a score vector (non-negative and non-increasing).
- Created a
shortPlackettLuce
class which allows you to generate ballots of arbitrary length in the style of PL. - Added tests for
__add__
method ofPreferenceProfile
. - Added
SlatePreference
model and tests.
Changed
-
Change the way the
condense_ballots()
method works in profiles. Rather than altering the original profile, it returns a new profile. This gives users the option to preserve the original profile. -
Alter
STV
class so that the remaining candidates are always listed in order of current first place votes. -
Made
PlackettLuce
a subclass ofshortPlackettLuce
. -
Change
PlackettLuce
,BradleyTerry
, andCumulative
ballot generators to havename_
prefix. This is in contrast to theslate_
models we have introduced. -
Speed improvements for various ballot generators.
-
pref_interval_by_bloc
is nowpref_intervals_by_bloc
in all ballot generators. This is now a dictionary of dictionaries, where the both sets of keys are the blocs, and the values of the sub-dictionaries are PreferenceInterval objects. The slate models require that we sample from the uncombined PreferenceInterval objects, while the name models require that we combine the PreferenceInterval objects using cohesion parameters. -
MDS plot functionality, splitting it into
compute_MDS
which computes the coordinates, andplot_MDS
which plots them. Made because the computation is the most time intensive.
Fixed
- Fixed an error in the
PreferenceProfile
tail method. - Errors in bloc labeling in
CambridgeSampler
.
Deprecations
- Deprecated PL and BT to name_PL and name_BT
Full Changelog: v1.1.1...v2.0.0
v1.1.1
VoteKit 1.1.1 is a patch update aimed primarily at extending the functionality of VoteKit. More specifically, this release implements score-based voting systems, and does so without editing the ballot class. To use a score-based system, you have to decide how many points to assign to each position of the ranking. This is flexible enough to handle things like cumulative and approval voting.
This update also includes some additional functionality that was included after creating and running some tutorials on usage of the software. For recordings and copies of some of these notebooks, please see the main website for VoteKit.
Key Changes
- Change the way the
condense_ballots()
method works in profiles. Rather than altering the original profile, it returns a new profile. - Altered
STV
class so that the remaining candidates are always listed in order of current first place votes. - Added print statement to
BallotGraph
so that when you draw the graph without labels, it prints a dictionary of candidate labels for you.
Additions
- Added a
by_bloc
parameter togenerate_profile
. If True, this returns a dictionary ofPreferenceProfile
objects by bloc. Defaults to False for backwards compatibility. - Created a
Cumulative
ballot generator class. TheCumulative
class works like PL, but samples with replacement instead of without. The ranking order does not matter here, simply that candidates are listed on the ballot with multiplicity. - Created a
HighestScore
election class. This takes in a profile and a score vector, and returns the$m$ candidates with highest scores. - Created a
Cumulative
election class which is just a subclass ofHighestScore
with the score vector set to all 1s. - Wrote an
__add__
method forPreferenceProfile
that combines the ballot lists of two profiles. - Created utility functions to compute the winners of a profile given a score vector, as well as to validate a score vector (non-negative and non-increasing).
- Add an
IRV
election class, which is just a wrapper forSTV
with 1 seat. - Add default option to
Borda
election class, so users do not have to input a score vector.
Add several methods toPairwiseComparisonGraph
.- Added two boolean methods that return True if there is a condorcet winner or if there is a condorcet cycle.
- Added two get methods that return the winner or the cycles. Cached the results of
dominating_tiers
andget_condorcet_cycles
.
- Added optional
to_float
method tofirst_place_votes
if users want to see them as floats instead of Fractions.
Bug Fixes
- Fixed an error in the
PreferenceProfile
tail method.
Full Changelog: v1.1.0..v1.1.1
v1.1.0
Votekit 1.1.0 features a number of important functional and syntactical changes to the core Ballot, PreferenceProfile, and ElectionState objects. It also includes changes to ballot generation methods to output the correct number of ballots and allow for user-defined block names in the CambridgeSampler class. This release marks an overhaul to the library's documentation, and the addition of section explaining the social choice theory that underpins Votekit's functionality.
Key Changes
- Method names for
ElectionState
methods - Caches for the results of
run_election()
Ballot
objects made immutable, using Pydantic dataclass- Parameter names for
CambridgeSampler
BallotGraph
now always displays vote totals for a ballotElectionState
now prints the current round whenever printingload_blt
becameload_scottish
plot_summary_stats
always displays candidates in order inputtedPreferenceProfile
data frame now has Percent column, removed the Weight Share columnBallot
object can take floats and integers as weightsBallot
attributevoter
changed tovoter_set
Additions
- Added
to_dict()
,to_json()
functions forElectionState
- Scores attribute to
ElectionState
_rename_blocs
method toCambridgeSampler
to rename blocs to historical names.- Added
reset
andrun_to_step
methods toElection
class sort_by_weight
parameter tohead
andtail
methods ofPreferenceProfile
received_votes
parameter toget_candidates
method ofPreferenceProfile
__str__
method forBallot
Bug Fixes
- Multiple winners correctly ordered based off previous round's vote totals
CambridgeSampler
correctly computes the frequency of opposing bloc ballotsPreferenceProfile
no longer rounds all weights to integer when printing
Special thanks to Chris Donnay (@cdonnay) who made significant contributions to this release and is responsible for the improved tutorials and social choice theory sections of the documentation!
v1.0.2
- bug fixes to election types
- lowered pandas version requirements for wider compatibility
v1.0.1
- added elections submodule (e.g
from votekit.elections import STV, fractional_transfer
) - renamed CVR loaders to
load_csv
andload_blt
- better documentation
v1.0.0
Version 1.0
- User determined options for breaking ties
- Ballot Simplex object, refactored construction for ballot generator classes
- IC/IAC with generalized arguments
- Fixed package imports
- Improved handling of tied rankings within ballots
- Optimization for election helper functions
v0.2.0
Update pyproject.toml
v0.1.1
- Added MDS plotting
- Updated metrics to include: earth mover and Lp distances
- Bug fixes to PreferenceProfile and ballot generators
- More docstrings
v0.0.0
remove plotting subfolder