Enum ContractFeasibleStepError 

pub enum ContractFeasibleStepError {
    Dimension {
        beta: usize,
        direction: usize,
        expected: usize,
    },
    InfeasibleIterate {
        row: usize,
        scaled_slack: f64,
    },
    NonFinite {
        row: usize,
        scaled_slack: f64,
        scaled_drift: f64,
    },
    Carrier(String),
}

Why the contract-feasible ratio test could not answer.

Every variant is a violated PRECONDITION of the ratio test, never a small step: “no admissible step exists” is reported as ContractFeasibleStep::fraction == 0.0, not as an error.

Variants

Dimension

beta / direction widths disagree with the constraint carrier.

Fields

beta: usize

direction: usize

expected: usize

InfeasibleIterate

The CURRENT iterate violates a row by more than PRIMAL_FEASIBILITY_TOL, so the ratio test has no feasible origin to step from. This is the genuine “infeasible iterate” condition and stays loud.

Fields

row: usize

scaled_slack: f64

NonFinite

A row cannot be DECIDED by comparison: a non-finite row norm, bound, a·β or a·δ. Reported rather than skipped: every comparison in the rule is false for NaN, so a skipped row would silently certify a step that is not a number as fully feasible (gam#2721). The reported slack and drift are the scaled quantities as computed, so the offending one is visible.

Fields

row: usize

scaled_slack: f64

scaled_drift: f64

Carrier(String)

The carrier could not evaluate Aβ / Aδ or a row descriptor.

Trait Implementations

impl Clone for ContractFeasibleStepError

fn clone(&self) -> ContractFeasibleStepError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ContractFeasibleStepError

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

Formats the value using the given formatter.

impl Display for ContractFeasibleStepError

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

Formats the value using the given formatter.

impl PartialEq for ContractFeasibleStepError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ContractFeasibleStepError