testAdditions function

Test the sensitivity of a result to tactical voting.

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.

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

Returns

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))