Struct SymCsrMatrix

pub struct SymCsrMatrix<T>
where
    T: Float + Debug + Copy,
{
    pub data: Vec<T>,
    pub indptr: Vec<usize>,
    pub indices: Vec<usize>,
    pub shape: (usize, usize),
}

Symmetric Compressed Sparse Row (SymCSR) matrix

This format stores only the lower triangular part of a symmetric matrix to save memory and improve performance. Operations are optimized to take advantage of symmetry when possible.

Note

All operations maintain symmetry implicitly.

Fields

data: Vec<T>

CSR format data for the lower triangular part (including diagonal)

indptr: Vec<usize>

Row pointers (indptr): indices where each row starts in indices array

indices: Vec<usize>

Column indices for each non-zero element

shape: (usize, usize)

Matrix shape (rows, cols), always square

Implementations

impl<T> SymCsrMatrix<T>

where T: Float + Debug + Copy,

pub fn new( data: Vec<T>, indptr: Vec<usize>, indices: Vec<usize>, shape: (usize, usize), ) -> SparseResult<Self>

Create a new symmetric CSR matrix from raw data

Arguments

• data - Non-zero values in the lower triangular part
• indptr - Row pointers
• indices - Column indices
• shape - Matrix shape (n, n)

Returns

A symmetric CSR matrix

Errors

Returns an error if:

• The shape is not square
• The indices array is incompatible with indptr
• Any column index is out of bounds

pub fn from_csr(matrix: &CsrMatrix<T>) -> SparseResult<Self>

Convert a regular CSR matrix to symmetric CSR format

This will verify that the matrix is symmetric and extract the lower triangular part.

Arguments

• matrix - CSR matrix to convert

Returns

A symmetric CSR matrix

pub fn is_symmetric(matrix: &CsrMatrix<T>) -> bool

Check if a CSR matrix is symmetric

Arguments

• matrix - CSR matrix to check

Returns

true if the matrix is symmetric, false otherwise

pub fn shape(&self) -> (usize, usize)

Get the shape of the matrix

Returns

A tuple (rows, cols)

pub fn nnz_stored(&self) -> usize

Get the number of stored non-zero elements

Returns

The number of non-zero elements in the lower triangular part

pub fn nnz(&self) -> usize

Get the total number of non-zero elements in the full matrix

Returns

The total number of non-zero elements in the full symmetric matrix

pub fn get(&self, row: usize, col: usize) -> T

Get a single element from the matrix

Arguments

• row - Row index
• col - Column index

Returns

The value at position (row, col)

pub fn to_csr(&self) -> SparseResult<CsrMatrix<T>>

Convert to standard CSR matrix (reconstructing full symmetric matrix)

Returns

A standard CSR matrix with both upper and lower triangular parts

pub fn to_dense(&self) -> Vec<Vec<T>>

Convert to dense matrix

Returns

A dense matrix representation as a vector of vectors

Trait Implementations

impl<T> Clone for SymCsrMatrix<T>

where T: Float + Debug + Copy + Clone,

fn clone(&self) -> SymCsrMatrix<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Debug for SymCsrMatrix<T>

where T: Float + Debug + Copy + Debug,

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

Formats the value using the given formatter.