Struct BlockPartition 

pub struct BlockPartition {
    pub row_blocks: Vec<usize>,
    pub col_blocks: Vec<usize>,
}

Block boundaries of a partitioned matrix: row_blocks and col_blocks are boundary lists starting at 0 and ending at m, n (invariants (B1)–(B3)).

use xingo_sparse::BlockPartition;
// [A | I] with A 3 × 5: one row block, structural then logical columns.
let p = BlockPartition::from_sizes(&[3], &[5, 3]).unwrap();
assert_eq!((p.n_rows(), p.n_cols()), (3, 8));
assert_eq!(p.col_block(1), 5..8);
assert_eq!(p.col_block_of(6), 1); // a logical column
// The augmented system [−D Aᵀ; A δI] of the same A: order 5 + 3.
let k = BlockPartition::new(vec![0, 5, 8], vec![0, 5, 8]).unwrap();
assert_eq!(k.row_block(1).start, 5); // the dual of constraint i is row 5 + i

Fields

row_blocks: Vec<usize>

Row boundaries [0 = r_0 < r_1 < … < r_p = m].

col_blocks: Vec<usize>

Column boundaries [0 = c_0 < c_1 < … < c_q = n].

Implementations

impl BlockPartition

pub fn new( row_blocks: Vec<usize>, col_blocks: Vec<usize>, ) -> Result<Self, SparseError>

A partition from its boundary lists, validated ((B1)–(B3)).

pub fn from_sizes( row_sizes: &[usize], col_sizes: &[usize], ) -> Result<Self, SparseError>

A partition from the sizes of its blocks (prefix sums): [A | I] with A of m × n is from_sizes(&[m], &[n, m]). An error if a size is 0 (blocks are never empty) or a dimension exceeds u32::MAX.

pub fn check_invariants(&self) -> Result<(), SparseError>

Checks (B1)–(B3).

pub fn n_rows(&self) -> usize

Number of rows m (the last row boundary).

pub fn n_cols(&self) -> usize

Number of columns n (the last column boundary).

pub fn n_row_blocks(&self) -> usize

Number of row blocks p.

pub fn n_col_blocks(&self) -> usize

Number of column blocks q.

pub fn row_block(&self, k: usize) -> Range<usize>

The rows r_k..r_{k+1} of row block k.

Panics

If k ≥ p.

pub fn col_block(&self, l: usize) -> Range<usize>

The columns c_l..c_{l+1} of column block l.

Panics

If l ≥ q.

pub fn row_block_of(&self, i: usize) -> usize

The row block containing row i (Algorithm B).

Panics

If i ≥ m.

pub fn col_block_of(&self, j: usize) -> usize

The column block containing column j (Algorithm B).

Panics

If j ≥ n.

Trait Implementations

impl Clone for BlockPartition

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BlockPartition

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

Formats the value using the given formatter.

impl Eq for BlockPartition

impl PartialEq for BlockPartition

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for BlockPartition