The pareto_front crate is a Rust library to build a Pareto front incrementaly.
This is particularly useful in multi-objectives optimization where, instead of having a single maximum that one can easily keep track off, one might want to keep track of various trade-offs, none of which is best on all axis, found during the optimization.
This crate aims to be small yet very fast.
This crate gives you access to the ParetoFront type which can be created (empty or from an iterator), updated by adding new candidates (using the push or the extend method) and converted into an iterator, a slice or a vector.
Additionaly, the pareto_front_serde feature lets you serialize and deserialize the ParetoFront type using serde.
Elements to be inserted in the Pareto front should implement the Dominate trait:
```rust use pareto_front::{Dominate, ParetoFront};
/// type that will be pushed in the Pareto front
struct ParetoElement { cost: usize, // to be minimized quality: f32, // to be maximized }
/// implement the Dominate trait so that the elements can be pushed into the front
impl Dominate for ParetoElement
{
/// returns true is self is better than x on all fields that matter to us
fn dominate(&self, x: &Self) -> bool
{
(self.cost <= x.cost) && (self.quality >= x.quality) && (self != x)
}
}
```
New elements can be added to a Pareto front using the push method (one can also collect an iterator into a Pareto front):
```rust // data to be put in the front let x = ParetoElement { cost: 35, quality: 0.5 }; let y = ParetoElement { cost: 350, quality: 0.05 }; let z = ParetoElement { cost: 5, quality: 0.25 };
// insertions in the Pareto front let mut front = ParetoFront::new(); front.push(x); front.push(y);
// note that push returns a boolean to tell you if the point you just inserted is part of the current Pareto front
let zispareto_optimal = front.push(z);
```
The resulting Pareto front can be converted into an iterator, a slice or a vector.