Trait Objective 

pub trait Objective<F> {
    type Error;

    // Required method
    fn value(&mut self, x: &[F]) -> Result<F, Self::Error>;

    // Provided methods
    fn batch(&self) -> bool { ... }
    fn values(&mut self, xs: &[F], out: &mut [F]) -> Result<(), Self::Error> { ... }
    fn has_gradient(&self) -> bool { ... }
    fn gradient(&mut self, x: &[F], g: &mut [F]) -> Result<(), Self::Error> { ... }
}

A function of a slice of F to minimize. A closure that returns a Result is one. Differentiable adds a gradient.

Required Associated Types

type Error

What stops an evaluation, such as an error in the caller’s function or an interrupt.

Required Methods

fn value(&mut self, x: &[F]) -> Result<F, Self::Error>

The value at x.

Provided Methods

fn batch(&self) -> bool

Whether values evaluates a batch of points in one call. Nelder–Mead evaluates its first simplex and each shrink as a batch, and differential evolution each generation. Without batch, a search calls value on each point.

fn values(&mut self, xs: &[F], out: &mut [F]) -> Result<(), Self::Error>

The value at each row of xs, into out, with xs.len() / out.len() items to a row. Methods call it only where batch is true.

fn has_gradient(&self) -> bool

Whether gradient gives the gradient. L-BFGS needs one, and Method::choose picks L-BFGS for an objective that has one.

fn gradient(&mut self, x: &[F], g: &mut [F]) -> Result<(), Self::Error>

The gradient at x, into g. Methods call it only where has_gradient is true.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<F, E, V: FnMut(&[F]) -> Result<F, E>, G: FnMut(&[F], &mut [F]) -> Result<(), E>> Objective<F> for Differentiable<V, G>

type Error = E

impl<F, E, V: FnMut(&[F]) -> Result<F, E>> Objective<F> for V

type Error = E