Struct LbfgsDiagnostics 

pub struct LbfgsDiagnostics {
    pub pairs_accepted: usize,
    pub pairs_curvature_rejected: usize,
    pub pairs_evicted_by_memory: usize,
    pub gamma_clamp_hits: usize,
    pub line_search_backtracks: usize,
}

Counters surfaced by the L-BFGS solver.

Fields

pairs_accepted: usize

Number of (s, y) curvature pairs that passed the Cauchy-Schwarz filter sy > F::epsilon() · sqrt(ss · yy) and entered the history buffer.

pairs_curvature_rejected: usize

Number of curvature pairs rejected by the filter sy > F::epsilon() · sqrt(ss · yy) (negative or near-zero curvature, i.e. cosine angle near 0 between s and y).

pairs_evicted_by_memory: usize

Number of evict-then-push events: a new accepted pair was added while the history buffer was already at config.memory, so the oldest pair was dropped. With the FIFO eviction policy used here, the invariant `pairs_evicted_by_memory == max(0, pairs_accepted

• config.memory)` holds exactly at termination.

gamma_clamp_hits: usize

Number of iterations where the initial L-BFGS gamma was clamped to the open range (1e-3, 1e3) (i.e. raw_gamma was strictly outside) or substituted with 1.0 because sy/yy was non-finite. A raw_gamma exactly equal to a clamp boundary is not counted.

line_search_backtracks: usize

Total Armijo line-search trial points beyond the first per outer iteration, summed across all iterations. A high value relative to iterations signals the search direction is poorly scaled.

Trait Implementations

impl Clone for LbfgsDiagnostics

fn clone(&self) -> LbfgsDiagnostics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LbfgsDiagnostics

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

Formats the value using the given formatter.

impl Default for LbfgsDiagnostics

fn default() -> LbfgsDiagnostics

Returns the “default value” for a type.