Voting Data

Rank choice voting data is compressed and stored efficiently in a object type called Ranks, which has two fields:

• uranks: a vector of unique rank choice vectors
• counts: a vector of counts corresponding to the number of votes for each unique rank choice vector

Below, we provide two examples for converting rank choice data into the appropriate format for a Ranks data object.

Example 1

In this first example, the rank choice votes of each individual is contained in a vector. All of the individual vectors are wrapped in a larger vector. Here is a simple case using four hypothetical individuals:

using RankChoiceVoting
data = [[:a,:b,:c],[:a,:c,:b],[:a,:c,:b],[:b,:a,:c]]

4-element Vector{Vector{Symbol}}:
 [:a, :b, :c]
 [:a, :c, :b]
 [:a, :c, :b]
 [:b, :a, :c]

The output above shows that the first and fourth individuals have unique rank choices, whereas the second and third individuals have the same rank choices. We can pass the data vector to the Ranks construct to create a more efficent data representation:

rankings = Ranks(data)

Ranks
┌────────┬──────────────┐
│ Counts │ Ranks        │
├────────┼──────────────┤
│ 1      │ [:a, :b, :c] │
│ 2      │ [:a, :c, :b] │
│ 1      │ [:b, :a, :c] │
└────────┴──────────────┘

Example 2

Unlike the example above, where ranks for each individual was provided, this second example shows how construct a Rank data object from pre-processed data. The code block shows the pre-processed data as a unique vector of ranks, unique_ranks, and the associated counts in a vector called counts.

using RankChoiceVoting
unique_ranks = [[:a,:b,:c],[:a,:c,:b],[:b,:a,:c]]
counts = [1,2,1]
rankings = Ranks(counts, unique_ranks)

Ranks
┌────────┬──────────────┐
│ Counts │ Ranks        │
├────────┼──────────────┤
│ 1      │ [:a, :b, :c] │
│ 2      │ [:a, :c, :b] │
│ 1      │ [:b, :a, :c] │
└────────┴──────────────┘