Struct SquareMatrix 

pub struct SquareMatrix { /* private fields */ }

Row-major n×n dense matrix of f64. Maps to Foam::scalarSquareMatrix.

LU decomposition uses Crout’s algorithm with scaled partial pivoting, matching Foam::LUDecompose(scalarSquareMatrix&, labelList&).

Implementations

impl SquareMatrix

pub fn new(n: usize) -> Self

Allocate an n×n matrix initialised to all zeros.

pub fn n(&self) -> usize

The matrix order n (number of rows = number of columns).

pub fn get(&self, i: usize, j: usize) -> f64

Element in row i, column j (both 0-based, must be < n).

pub fn set(&mut self, i: usize, j: usize, v: f64)

Set the element in row i, column j to v (0-based indices < n).

pub fn add(&mut self, i: usize, j: usize, v: f64)

Add v to the element in row i, column j (0-based indices < n).

pub fn fill_zero(&mut self)

Reset every entry to zero, keeping the same order n.

pub fn lu_decompose(&mut self) -> Vec<usize>

In-place LU decomposition with scaled partial pivoting.

After the call, self holds the combined LU factors (lower strictly triangular, upper including diagonal). Returns the pivot-row indices.

pub fn lu_back_substitute(&self, pivot: &[usize], b: &mut Vec<f64>)

Solve LU·x = b in-place (b is overwritten with the solution).

Must be called after lu_decompose. Matches Foam::LUBacksubstitute(scalarSquareMatrix&, labelList&, List<scalar>&).

pub fn solve(&self, rhs: &[f64]) -> Result<Vec<f64>, MatrixError>

Convenience: decompose a copy and solve A·x = b.

Returns Err(MatrixError::Singular) if the matrix has an exactly-zero pivot column (the LU sentinel f64::EPSILON was written to the diagonal). Ill-conditioned but non-singular matrices are not detected; for those, check the residual ‖Ax − b‖ manually.

Trait Implementations

impl Clone for SquareMatrix

fn clone(&self) -> SquareMatrix

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SquareMatrix

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

Formats the value using the given formatter.