Struct Lu 

pub struct Lu {
    pub lu: Vec<f64>,
    pub pivots: Vec<usize>,
    pub sign: f64,
    pub singular: bool,
    pub n: usize,
}

An in-place LU decomposition with partial pivoting (Doolittle), P·A = L·U.

Fields

lu: Vec<f64>

Combined factors, row-major n×n: U on/above the diagonal, the strictly-lower part of L below it (L’s unit diagonal is implicit).

pivots: Vec<usize>

Row permutation: pivots[i] is the original row now in position i.

sign: f64

Sign of the permutation (+1/-1), i.e. det(P).

singular: bool

true if a zero pivot was encountered (matrix is singular).

n: usize

Implementations

impl Lu

pub fn solve(&self, b: &[f64]) -> Option<Vec<f64>>

Solve A x = b using this factorization (apply P, forward-substitute L, back-substitute U). None if the matrix is singular or b has the wrong length. O(n²) given the existing O(n³) factorization — the reusable solve behind any dense linear system (BVP Newton steps, implicit ODE stages, least-squares normal equations).

pub fn determinant(&self) -> f64

det(A) = sign · Π U[i][i].

Trait Implementations

impl Clone for Lu

fn clone(&self) -> Lu

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Lu

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

Formats the value using the given formatter.