Struct CscMatrix 

#[non_exhaustive]
pub struct CscMatrix { /* private fields */ }

Compressed Sparse Column matrix.

Efficient for column iteration (tree fit, linear algebra). indptr[j]..indptr[j+1] gives the range for column j.

Implementations

impl CscMatrix

pub fn from_triplets( rows: &[usize], cols: &[usize], vals: &[f64], n_rows: usize, n_cols: usize, ) -> Result<Self>

Build a CSC matrix from COO (triplet) format.

Duplicate entries at the same (row, col) are summed.

pub fn from_dense(cols: &[Vec<f64>]) -> Self

Convert a column-major dense matrix to CSC (zeros are skipped).

cols[j][i] = value at row i, column j.

pub fn n_rows(&self) -> usize

Number of rows.

pub fn n_cols(&self) -> usize

Number of columns.

pub fn nnz(&self) -> usize

Number of stored non-zero entries.

pub fn density(&self) -> f64

Fraction of non-zero entries.

pub fn col(&self, j: usize) -> SparseCol<'_>

View of column j as sparse (row, value) pairs.

pub fn get(&self, row: usize, col: usize) -> f64

Retrieve a single element. Returns 0.0 if not stored.

pub fn to_csr(&self) -> CsrMatrix

Convert to CSR format in O(nnz).

pub fn to_dense(&self) -> Vec<Vec<f64>>

Convert to dense row-major format.

pub fn dot_vec(&self, x: &[f64]) -> Vec<f64>

Sparse matrix-vector multiply: y = A * x.

Trait Implementations

impl Clone for CscMatrix

fn clone(&self) -> CscMatrix

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CscMatrix

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

Formats the value using the given formatter.