Class ElectoralSystems

java.lang.Object
org.episteme.social.politics.ElectoralSystems
public final class ElectoralSystems extends Object
Provides algorithms for various electoral systems and seat allocation methods. Includes implementations of D'Hondt and Sainte-Laguë proportional representation methods.
Since:
1.0
Version:
1.1
Author:
Silvere Martin-Michiellot, Gemini AI (Google DeepMind)

  • Method Details

    • allocateSeatsDHondt

      public static Map<String,Integer> allocateSeatsDHondt(Map<String,Long> votes, int totalSeats)
      Allocates seats using the D'Hondt method (highest averages).

      Favors larger parties slightly more than other PR methods. Divisors: 1, 2, 3, 4...

      Parameters:
      votes - Map of party names to their total votes
      totalSeats - Total seats available for allocation
      Returns:
      Map of party names to allocated seats

    • allocateSeatsSainteLague

      public static Map<String,Integer> allocateSeatsSainteLague(Map<String,Long> votes, int totalSeats)
      Allocates seats using the Sainte-Laguë method (Webster method).

      Generally provides a more proportional outcome than D'Hondt, better for smaller parties. Divisors: 1, 3, 5, 7... (2s + 1)

      Parameters:
      votes - Map of party names to their total votes
      totalSeats - Total seats available for allocation
      Returns:
      Map of party names to allocated seats

    • predictSwing

      public static Map<String,Real> predictSwing(Map<String,Real> previousResults, Map<String,Real> swing)
      Implements a simple "Uniform Swing" model for predicting election outcomes. Applies a uniform percentage change to previous results.
      Parameters:
      previousResults - Map of parties to previous vote percentage (e.g., 0.45 for 45%)
      swing - Predicted swing in percentage points (e.g., +0.02 for +2%)
      Returns:
      Map of predicted vote percentages