testAdditions {SafeVote}

Test the sensitivity of a result to tactical voting.

Description

Ballots are added until a specified number of simulated elections (arep) have been held. If a favoured candidate is specified, then the ballot-box is stuffed with ballots awarding first-preference to this candidate. Alternatively, a tacticalBallot may be specified. If both favoured and tacticalBallot are NULL, then a random candidate is selected as the favoured one.

Usage

testAdditions(
  votes,
  ainc = 1,
  arep = NULL,
  favoured = NULL,
  tacticalBallot = NULL,
  rankMethod = "safeRank",
  countMethod = "stv",
  countArgs = list(),
  exptName = NULL,
  equiet = FALSE,
  everbose = FALSE
)

Arguments

votes

A set of ballots, as in vote_2.3.2

ainc

Number of ballots to be added in each step

arep

Maximum number of ballot-stuffed elections to run

favoured

Name of the candidate being "plumped". If NULL, a random candidate is selected from among the candidates not initially top-ranked. All other candidates are fully-ranked at random, with an identical ballot paper being stuffed multiple times. An integer value for favoured is interpreted as an index into the candidate names.

tacticalBallot

A ballot paper i.e. a vector of length ncol(ballots). If this argument is non-NULL, it takes precedence over favoured when the ballot box is being stuffed.

rankMethod

"safeRank" (default), "elected", or "rank". "rank" is a total ranking of the candidates, with ties broken at random. "elected" assigns rank=1 to elected candidates, rank=2 for eliminated candidates.

countMethod

countMethod "stv" (default) or "condorcet"

countArgs

List of args to be passed to countMethod (in addition to votes)

exptName

stem-name of experimental units e.g. "E". If NULL, then a 3-character string of capital letters is chosen at random.

equiet

TRUE to suppress all experimental output

everbose

TRUE to produce diagnostic output from the experiment

Value

A matrix of experimental results, of dimension n by 2m+1, where n is the number of elections and m is the number of candidates. The first column is named "nBallots". Other columns indicate the ranking of the eponymous candidate, and their margin over the next-lower-ranked candidate.

Examples

data(food_election) 
testAdditions(food_election, arep = 2, favoured = "Strawberries", 
  countArgs = list(safety = 0))