borda_method: Borda Count Method

In votesys: Voting Systems, Instant-Runoff Voting, Borda Method, Various Condorcet Methods

Description

Both ordinary Borda method and modified Borda method are available. In an ordinary Borda system, voters are required to assign score values to candidates. See Details.

Usage

borda_method(x, allow_dup = TRUE, min_valid = 1, modified = FALSE)

Arguments

x	an object of class vote.
allow_dup	whether ballots with duplicated score values are taken into account. Default is TRUE.
min_valid	default is 1. If the number of valid entries of a ballot is less than this value, the ballot will not be used.
modified	if the modified Borda is to be used. Default is FALSE.

Details

Suppose there are 5 candidates. A voter's 1st choice gets 1 point, the 2nd choice gets 2 points... Candidate with the smallest total score wins. The function does not require voters to assign scores to all candidates, for NAs are automatically assigned the highest (worst) score. Duplicated values (two or more candidates share the same score) are also allowed (note: NAs and ties may not be allowed in real ballots).

In modified Borda, the rule changes. Suppose there are 5 candidates. A voter writes down 5 candidates and his 1st choice gets 5 points. The one who gets the largest total score wins. However, if the voter only write down 2 names, then, his 1st choice gets only 2 points rather than 5 points. Thus the modified Borda encourages voters to write down more names. Besides, in modified Borda, only the ranks of true scores, rather than the true scores themselves, are used. If the raw data is a list each ballot of which contains candidate names, scores can also be extracted, that is, the 1st position is the 1st choice which gets 1 point, the 2nd position, 2 points, and so on.

Value

a list object.

• (1) call the function call.

• (2) method the counting method.

• (3) candidate candidate names.

• (4) candidate_num number of candidate.

• (5) ballot_num number of ballots in x.

• (6) valid_ballot_num number of ballots that are used to compute the result.

• (7) winner the winners.

• (8) modified whether the modified Borda is used.

• (9) other_info a list with 2 elements, if modified is FALSE, then count_min records the total scores, count_max is NULL; if modified is TRUE, the vice versa.

Examples

raw <- c(
    rep(c('m', 'n', 'c', 'k'), 42), 
    rep(c('n', 'c', 'k', 'm'), 26), 
    rep(c('c', 'k', 'n', 'm'), 15), 
    rep(c('k', 'c', 'n', 'm'), 17)
) 
raw <- matrix(raw, ncol = 4, byrow = TRUE)
vote <- create_vote(raw, xtype = 2, candidate = c('m', 'n', 'c', 'k'))
y <- borda_method(vote)

raw <- list(c('a', 'e', 'c', 'd', 'b'), c('b', 'a', 'e'), 
    c('c', 'd', 'b'), c('d', 'a', 'e')
)
vote <- create_vote(raw, xtype = 3, candidate = c('a', 'b', 'c', 'd', 'e'))
y <- borda_method(vote, modified = TRUE)

Example output

MATCHING NAMES AND SCORES
COUNTING NA AND DUP VALUES
MAKING CONDORCET TABLE
COLLECTING RESULT
DONE
SELECTING
COLLECTING RESULT
Winner is with the lowest score, for modified is FALSE.
DONE
MATCHING NAMES AND SCORES
COUNTING NA AND DUP VALUES
MAKING CONDORCET TABLE
COLLECTING RESULT
DONE
When modified is TRUE, allow_dup is automatically set to FALSE, ignoring value given by user.
SELECTING
COLLECTING RESULT
Winner is with the largest score, for modified is TRUE.
DONE

votesys documentation built on May 2, 2019, 1:32 p.m.