maximal-lottery 0.1.1

A Rust library for computing maximal lotteries from preference profiles.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47

# maximal-lottery

A Rust library for computing maximal lotteries from preference profiles.

Maximal lottery is a probabilistic voting rule: voters express pairwise
preferences between candidates, the profile is turned into a margin matrix,
and that matrix is treated as a symmetric zero-sum game. A maximal lottery
is a maximin strategy of that game.

## Ranked ballots

```rust
use maximal_lottery::ballot::RankedBallot;
use maximal_lottery::prelude::*;

let n = 3;
let c = Candidate;

let ballot = RankedBallot::total(&[c(0), c(1), c(2)], n).unwrap();

let profile = PreferenceProfile::try_new(vec![ballot]).unwrap();
let margins = profile.tally_margins();
let lottery = CentroidSolver.solve(&margins).unwrap();
```

## Pairwise ballots

```rust
use maximal_lottery::ballot::{PairPreference, PairwiseBallot};
use maximal_lottery::prelude::*;

let n = 3;
let c = Candidate;
let ballot = PairwiseBallot::from_pairs(
    &[
        (c(0), c(1), PairPreference::Left),
        (c(1), c(2), PairPreference::Left),
        (c(0), c(2), PairPreference::Left),
    ],
    n,
)
.unwrap();

let profile = PreferenceProfile::try_new(vec![ballot]).unwrap();
let margins = profile.tally_margins();
let lottery = CentroidSolver.solve(&margins).unwrap();
```