org.bolson.vote
Class IRV

java.lang.Object
  org.bolson.vote.VotingSystem
      org.bolson.vote.RankedVotingSystem
          org.bolson.vote.IRV

All Implemented Interfaces:

java.io.Serializable

public class IRV
extends RankedVotingSystem

Implements the Instant Runoff Voting, also known as Single Transferrable Vote. There's wide debate about the flaws and virtues of this system.

See Also:

Condorcet, IRNR, Serialized Form

Field Summary

protected java.util.Vector	votes
protected java.util.Vector[]	winnerBuckets

Fields inherited from class org.bolson.vote.VotingSystem

debug, NO_VOTE, numc

Constructor Summary

IRV(int numCandidates)

Method Summary

java.lang.String	getDebugText(java.lang.String[] names) Return textual representation of debug data.
int[]	getWinners() Do processing if necessary, return winners.
int[]	getWinners(java.io.PrintWriter out, int numSeats) Multi-seat IRV, aka STV.
java.lang.String	htmlSummary(java.lang.String[] names) A fancy html representation.
VotingSystem	init(java.lang.String[] argv) Set what happens when a vote has a duplicate rating (among active choices) -split|-dup|-dq
protected void	intoBucket(int[] ranking)
protected void	myInit()
java.lang.String	name() Return name of this voting system.
void	resetBuckets()
java.lang.String	toString()
java.lang.String	toString(java.lang.String[] names) A more interesting representation.
int	voteRanking(int[] ranking)

Methods inherited from class org.bolson.vote.RankedVotingSystem

voteRating, voteRating, voteRating

Methods inherited from class org.bolson.vote.VotingSystem

checkRatedVote, getDebugHTML, getNumberOfCandidates, getWinners, getWinners, isValidRankedVote, isValidRatedVote, normalize, normalize, normalize, normalize, normalize, normalizeL2, normalizeL2, normalizeL2, normalizeL2, normalizeL2, stretch, voteRating

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

votes

protected java.util.Vector votes

winnerBuckets

protected java.util.Vector[] winnerBuckets

Constructor Detail

IRV

public IRV(int numCandidates)

Method Detail

myInit

protected void myInit()

name

public java.lang.String name()

Description copied from class: VotingSystem

Return name of this voting system. This is a function so that it can potentially construct a detailed name based on options set in init().

Overrides:

name in class VotingSystem

Returns:

a descriptive name

intoBucket

protected void intoBucket(int[] ranking)

voteRanking

public int voteRanking(int[] ranking)

Specified by:

voteRanking in class VotingSystem

Parameters:

ranking - An array int[N]. ranking[i] is the ranking of choice i. rankings are 1 (most preferred) through N (least). INT_MAX, N, or NO_VOTE for unspecified.

Returns:

0 on success

resetBuckets

public void resetBuckets()

getWinners

public int[] getWinners()

Description copied from class: VotingSystem

Do processing if necessary, return winners.

It is recommended to cache the return value in such a way that calling this function again does not do complex recalculation. That cache should be cleared if voteRating or voteRanking is called.

Specified by:

getWinners in class VotingSystem

Returns:

indecies of winners (hopefully 1 of them)

getDebugText

public java.lang.String getDebugText(java.lang.String[] names)

Description copied from class: VotingSystem

Return textual representation of debug data. Default implementation returns null.

Overrides:

getDebugText in class VotingSystem

Parameters:

names - Symbolic names for the choices makes human debugging easier. May be null.

Returns:

debug text (default=null)

See Also:

VotingSystem.debug

getWinners

public int[] getWinners(java.io.PrintWriter out,
                        int numSeats)

Multi-seat IRV, aka STV. In this case, "-split" refers to the overvote. With -split, votes for a winner maintain a fraction of their voting power proportional to the number of votes beyond the droop quota. By default a random set of ballots beyond the droop quota are transferred in whole to their remaining choices.

Overrides:

getWinners in class VotingSystem

Parameters:

out - where to print news and diagnostics

numSeats - the number of seats available.

Returns:

indecies of winners, hopefully numSeats of them but in case of ties there may be more and in case of some internal schism there may be fewer. Check .length to be sure.

See Also:

VotingSystem.getWinners(int), VotingSystem.debug, VotingSystem.getDebugText(String[]), VotingSystem.getDebugHTML(String[])

htmlSummary

public java.lang.String htmlSummary(java.lang.String[] names)

Description copied from class: VotingSystem

A fancy html representation. Include the names of the choices voted upon in the representation.

Specified by:

htmlSummary in class VotingSystem

Parameters:

names - The names of the choices. May be null.

Returns:

state, with names!

toString

public java.lang.String toString(java.lang.String[] names)

Description copied from class: VotingSystem

A more interesting representation. Include the names of the choices voted upon in the representation.

Specified by:

toString in class VotingSystem

Parameters:

names - The names of the choices.

Returns:

state, with names!

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

init

public VotingSystem init(java.lang.String[] argv)

Set what happens when a vote has a duplicate rating (among active choices) -split|-dup|-dq

Overrides:

init in class VotingSystem

Returns:

this so that you can do

vs = (new VS(numc)).init( new String[]{"blah", "grunt"} );