`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) .

## 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 . .