# Struct argmin::solver::trustregion::TrustRegion

``pub struct TrustRegion<R, F> { /* private fields */ }``
Expand description

## Trust region method

The trust region method approximates the cost function within a certain region around the current point in parameter space. Depending on the quality of this approximation, the region is either expanded or contracted.

The calculation of the actual step length and direction is performed by a method which implements `TrustRegionRadius`, such as:

### Requirements on the optimization problem

The optimization problem is required to implement `CostFunction`, `Gradient` and `Hessian`.

### Reference

Jorge Nocedal and Stephen J. Wright (2006). Numerical Optimization. Springer. ISBN 0-387-30303-0.

## Implementations§

source§

### impl<R, F> TrustRegion<R, F>where F: ArgminFloat,

source

#### pub fn new(subproblem: R) -> Self

Construct a new instance of `TrustRegion`

##### Example
``````use argmin::solver::trustregion::{CauchyPoint, TrustRegion};
let cp: CauchyPoint<f64> = CauchyPoint::new();
let tr: TrustRegion<_, f64> = TrustRegion::new(cp);``````
source

Defaults to `1.0`.

##### Example
``````let cp: CauchyPoint<f64> = CauchyPoint::new();
let tr: TrustRegion<_, f64> = TrustRegion::new(cp).with_radius(0.8)?;``````
source

Defaults to `100.0`.

##### Example
``````let cp: CauchyPoint<f64> = CauchyPoint::new();
let tr: TrustRegion<_, f64> = TrustRegion::new(cp).with_max_radius(1000.0)?;``````
source

#### pub fn with_eta(self, eta: F) -> Result<Self, Error>

Set eta

Must lie in `[0, 1/4)` and defaults to `0.125`.

##### Example
``````let cp: CauchyPoint<f64> = CauchyPoint::new();
let tr: TrustRegion<_, f64> = TrustRegion::new(cp).with_eta(0.2)?;``````

## Trait Implementations§

source§

### impl<R: Clone, F: Clone> Clone for TrustRegion<R, F>

source§

#### fn clone(&self) -> TrustRegion<R, F>

Returns a copy of the value. Read more
1.0.0 · source§

#### fn clone_from(&mut self, source: &Self)

Performs copy-assignment from `source`. Read more
source§

### impl<'de, R, F> Deserialize<'de> for TrustRegion<R, F>where R: Deserialize<'de>, F: Deserialize<'de>,

source§

#### fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer. Read more
source§

### impl<R, F> Serialize for TrustRegion<R, F>where R: Serialize, F: Serialize,

source§

#### fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>where __S: Serializer,

Serialize this value into the given Serde serializer. Read more
source§

### impl<O, R, F, P, G, H> Solver<O, IterState<P, G, (), H, F>> for TrustRegion<R, F>where O: CostFunction<Param = P, Output = F> + Gradient<Param = P, Gradient = G> + Hessian<Param = P, Hessian = H>, P: Clone + Debug + SerializeAlias + DeserializeOwnedAlias + ArgminL2Norm<F> + ArgminDot<P, F> + ArgminDot<G, F> + ArgminAdd<P, P>, G: Clone + SerializeAlias + DeserializeOwnedAlias, H: Clone + SerializeAlias + DeserializeOwnedAlias + ArgminDot<P, P>, R: Clone + TrustRegionRadius<F> + Solver<O, IterState<P, G, (), H, F>>, F: ArgminFloat,

source§

#### const NAME: &'static str = "Trust region"

Name of the solver. Mainly used in Observers.
source§

source§

#### fn next_iter( &mut self, problem: &mut Problem<O>, state: IterState<P, G, (), H, F> ) -> Result<(IterState<P, G, (), H, F>, Option<KV>), Error>

Computes a single iteration of the algorithm and has access to the optimization problem definition and the internal state of the solver. Returns an updated `state` and optionally a `KV` which holds key-value pairs used in Observers.
source§

#### fn terminate(&mut self, _state: &IterState<P, G, (), H, F>) -> TerminationStatus

Used to implement stopping criteria, in particular criteria which are not covered by (`terminate_internal`. Read more
source§

#### fn terminate_internal(&mut self, state: &I) -> TerminationStatus

Checks whether basic termination reasons apply. Read more

§

§

§

§

§

## Blanket Implementations§

source§

### impl<T> Any for Twhere T: 'static + ?Sized,

source§

#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more
source§

### impl<T> Borrow<T> for Twhere T: ?Sized,

const: unstable · source§

#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

### impl<T> BorrowMut<T> for Twhere T: ?Sized,

const: unstable · source§

#### fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
source§

### impl<T> From<T> for T

const: unstable · source§

#### fn from(t: T) -> T

Returns the argument unchanged.

source§

### impl<T, U> Into<U> for Twhere U: From<T>,

const: unstable · source§

#### fn into(self) -> U

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

source§

### impl<T> ToOwned for Twhere T: Clone,

§

#### type Owned = T

The resulting type after obtaining ownership.
source§

#### fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

#### fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
source§

### impl<T, U> TryFrom<U> for Twhere U: Into<T>,

§

#### type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source§

#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

### impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

§

#### type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
const: unstable · source§

#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
§

§

source§

source§