dirtree {elections.dtree}

Create a Dirichlet-tree object

Description

dirtree is used to create a Dirichlet-tree for modelling ballots, as described by Everest et al. (2022).

Usage

dirtree(
  candidates,
  min_depth = 0,
  max_depth = length(candidates),
  a0 = 1,
  vd = FALSE
)

Arguments

candidates

A character vector, with each element (must be unique) representing a single candidate.

min_depth

The minimum number of candidates which must be specified for a valid ballot.

max_depth

The maximum number of candidates which can be specified for a valid ballot.

a0

The prior parameter for the distribution.

vd

A flag which, when TRUE, employs a parameter structure which reduces to a regular Dirichlet distribution as described by Everest et al. (2022).

Value

A Dirichlet-tree representing ranked ballots, as an object of class dirichlet_tree.

References

Everest F, Blom M, Stark PB, Stuckey PJ, Teague V, Vukcevic D (2023). “Ballot-Polling Audits of Instant-Runoff Voting Elections with a Dirichlet-Tree Model.” In Computer Security. ESORICS 2022 International Workshops, 525–540. ISBN 978-3-031-25460-4..

Everest F, Blom M, Stark PB, Stuckey PJ, Teague V, Vukcevic D (2022). “Auditing Ranked Voting Elections with Dirichlet-Tree Models: First Steps.” doi:10.15157/diss/021..