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 to generate_profile. If True, this returns a dictionary of PreferenceProfile objects by bloc. Defaults to False for backwards compatibility.
• Created a Cumulative ballot generator class. The Cumulative 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 of HighestScore with the score vector set to all 1s.
• Wrote an __add__ method for PreferenceProfile 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 for STV with 1 seat.
• Add default option to Borda election class, so users do not have to input a score 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 of dominating_tiers and get_condorcet_cycles.
• Added optional to_float method to first_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