Enum LineSearchAlgorithm 

pub enum LineSearchAlgorithm {
    MoreThuente,
    BacktrackingArmijo,
    BacktrackingStrongWolfe,
    BacktrackingWolfe,
}

Line search algorithms.

Variants

MoreThuente

MoreThuente method proposd by More and Thuente. This is the default for regular LBFGS.

BacktrackingArmijo

Backtracking method with the Armijo condition.

The backtracking method finds the step length such that it satisfies the sufficient decrease (Armijo) condition,

• f(x + a * d) <= f(x) + ftol * a * g(x)^T d,

where x is the current point, d is the current search direction, and a is the step length.

BacktrackingStrongWolfe

Backtracking method with strong Wolfe condition.

The backtracking method finds the step length such that it satisfies both the Armijo condition (BacktrackingArmijo) and the following condition,

• |g(x + a * d)^T d| <= gtol * |g(x)^T d|,

where x is the current point, d is the current search direction, and a is the step length.

BacktrackingWolfe

Backtracking method with regular Wolfe condition.

The backtracking method finds the step length such that it satisfies both the Armijo condition (BacktrackingArmijo) and the curvature condition,

• g(x + a * d)^T d >= gtol * g(x)^T d,

where x is the current point, d is the current search direction, and a is the step length.

Trait Implementations

impl Clone for LineSearchAlgorithm

fn clone(&self) -> LineSearchAlgorithm

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LineSearchAlgorithm

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for LineSearchAlgorithm

fn default() -> Self

The default algorithm (MoreThuente method).

impl PartialEq for LineSearchAlgorithm

fn eq(&self, other: &LineSearchAlgorithm) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for LineSearchAlgorithm

impl StructuralPartialEq for LineSearchAlgorithm