Trait vrp_core::algorithms::nsga2::Objective

pub trait Objective {
    type Solution;
    fn total_order(&self, a: &Self::Solution, b: &Self::Solution) -> Ordering;
    fn distance(&self, a: &Self::Solution, b: &Self::Solution) -> f64;
    fn fitness(&self, solution: &Self::Solution) -> f64;
}

An objective defines a total ordering relation and a distance metric on a set of solutions. Given any two solutions, an objective answers the following two questions:

• "which solution is the better one" (total order)
• "how similar are the two solutions" (distance metric)

Associated Types

type Solution

The solution value type that we define the objective on.

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Required methods

fn total_order(&self, a: &Self::Solution, b: &Self::Solution) -> Ordering

An objective defines a total ordering between any two solution values.

This answers the question, is solution a better, equal or worse than solution b, according to the objective.

fn distance(&self, a: &Self::Solution, b: &Self::Solution) -> f64

An objective defines a distance metric between any two solution values.

The distance metric answer the question, how similar the solutions a and b are, according to the objective. A zero value would mean, that both solutions are in fact the same, according to the objective. Larger magnitudes would mean "less similar".

fn fitness(&self, solution: &Self::Solution) -> f64

An objective fitness value for given solution.

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Implementors

impl Objective for ObjectiveCost

type Solution = InsertionContext

fn total_order(&self, a: &Self::Solution, b: &Self::Solution) -> Ordering

fn distance(&self, _a: &Self::Solution, _b: &Self::Solution) -> f64

fn fitness(&self, solution: &Self::Solution) -> f64

impl Objective for TotalRoutes

type Solution = InsertionContext

fn total_order(&self, a: &Self::Solution, b: &Self::Solution) -> Ordering

fn distance(&self, a: &Self::Solution, b: &Self::Solution) -> f64

fn fitness(&self, solution: &Self::Solution) -> f64

impl Objective for TotalTransportCost

type Solution = InsertionContext

fn total_order(&self, a: &Self::Solution, b: &Self::Solution) -> Ordering

fn distance(&self, a: &Self::Solution, b: &Self::Solution) -> f64

fn fitness(&self, solution: &Self::Solution) -> f64

impl Objective for TotalUnassignedJobs

type Solution = InsertionContext

fn total_order(&self, a: &Self::Solution, b: &Self::Solution) -> Ordering

fn distance(&self, a: &Self::Solution, b: &Self::Solution) -> f64

fn fitness(&self, solution: &Self::Solution) -> f64

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