Enum PositiveSemidefiniteViolation 

#[non_exhaustive]
pub enum PositiveSemidefiniteViolation {
    #[non_exhaustive]
    NegativePivot {
        value: f64,
    },
    #[non_exhaustive]
    ZeroPivotCoupling {
        row: usize,
        value: f64,
    },
}

Computed LDLT condition that violates the no-pivot positive-semidefinite factorization requirements.

These values are computed in binary64. They explain why LDLT rejected the matrix, but do not prove that the stored matrix is exactly indefinite.

Examples

use la_stack::prelude::*;

match LaError::not_positive_semidefinite_negative(1, -3.0) {
    LaError::NotPositiveSemidefinite {
        violation: PositiveSemidefiniteViolation::NegativePivot { value, .. },
        ..
    } => assert_eq!(value, -3.0),
    _ => unreachable!("constructor preserves the PSD violation"),
}

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

#[non_exhaustive]

NegativePivot

LDLT produced a strictly negative diagonal pivot.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

value: f64

Observed negative pivot value.

#[non_exhaustive]

ZeroPivotCoupling

A zero diagonal pivot still has a non-zero coupling below it.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

row: usize

Row containing the non-zero coupling.

value: f64

Observed coupling value.

Trait Implementations

impl Clone for PositiveSemidefiniteViolation

fn clone(&self) -> PositiveSemidefiniteViolation

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for PositiveSemidefiniteViolation

impl Debug for PositiveSemidefiniteViolation

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

Formats the value using the given formatter.

impl PartialEq for PositiveSemidefiniteViolation

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for PositiveSemidefiniteViolation