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Function to calculate the allocated seats according to the First Past the Post method in a given electoral district.

Source: R/seat_allocation.R
fptp_seats.Rd

This function allocates every seat in an electoral district to the candidacy that receives the largest number of ballots. In case of a tie in the number of ballots the seats will be randomly allocated between those candidacies.

Usage

fptp_seats(
  candidacies,
  ballots,
  blank_ballots,
  n_seats,
  threshold = 0.03,
  short_version = TRUE
)

Arguments

candidacies

A vector containing one of the following variable: unique codes or abbreviations of the candidacies that participated in the election.

ballots

A vector containing the absolute number of ballots (integer positive values) received by each candidacies

blank_ballots

A numerical value indicating the number of blank ballots (integer positive values).

n_seats

An integer positive value indicating the number of seats that are going to distributed for a given electoral district.

threshold

A numerical value (between 0 and 1) indicating the minimal percentage of ballots needed to obtain representation for a given electoral district. Defaults to 0.03.

short_version

Flag to indicate whether it should be returned a short version of the data (just key variables) or not. Defaults to TRUE.

Value

candidacies

abbrev or id of the candidacies

seats

number of seats distributed to each party

ballots

absolute number of ballots, just in long format

porc_seats

percentage of seats respect to the number of seats, just in long format

porc_ballots

percentage of ballots respect to party ballots (including blank ballots), just in long format

Details

The purpose of this helper function is to be used in a general function, seats_allocation(), to calculate the seats distribution of every electoral district of a given election according to the plurality method.

Author

Javier Alvarez-Liebana, Irene Bosque-Gala and David Pereiro-Pol

Examples

## Correct examples

## Seats distribution with First Past the Post method for given vectors
## of candidacies and ballots without the remainder quotients

candidacies <- c("PP", "PSOE", "PODEMOS", "VOX")
ballots <- c(200, 350, 100, 200)

seats <- fptp_seats(candidacies = candidacies, ballots = ballots,
blank_ballots = 50, n_seats = 15, threshold = 0.03)

# Same results in a long version (providing quotients)
seats <- fptp_seats(candidacies, ballots, blank_ballots = 50,
                      n_seats = 15, short_version = FALSE)

# Adams with threshold 0.05
seats <- fptp_seats(candidacies, ballots, blank_ballots = 50,
                      n_seats = 5, threshold = 0.05)

# A very high threshold that only one party meets
seats <- fptp_seats(candidacies, ballots, blank_ballots = 50,
                      n_seats = 5, threshold = 0.3)

if (FALSE) { # \dontrun{
# Incorrect examples

# Different length of candidacies and ballots

candidacies <- c("PP", "PSOE", "PODEMOS", "VOX")
ballots <- c(200, 350, 100)

seats <- fptp_seats(candidacies = candidacies, ballots = ballots,
 blank_ballots = 50, threshold = 0.03)

 # Ballots with missing values
candidacies <- c("PP", "PSOE", "PODEMOS")
ballots <- c(200, 350, NA)
seats <- fptp_seats(candidacies = candidacies, ballots = ballots,
                      n_seats = 5, blank_ballots = 50,
                      threshold = 0.03)

# Ballots with char values
candidacies <- c("PP", "PSOE", "PODEMOS")
ballots <- c("200", "350", "100")
seats <- fptp_seats(candidacies = candidacies, ballots = ballots,
                      n_seats = 5, blank_ballots = 50,
                      threshold = 0.03)

# Threshold should be a numerical value between 0 and 1
candidacies <- c("PP", "PSOE", "PODEMOS")
ballots <- c(200, 350, 100)
seats <- fptp_seats(candidacies = candidacies, ballots = ballots,
                      n_seats = 5, blank_ballots = 50,
                      threshold = 3)
} # }