Struct BoundaryMatrix 

pub struct BoundaryMatrix {
    pub matrix: Vec<Vec<u8>>,
    pub n_simplices: usize,
}

Boundary matrix over Z/2Z with column reduction for persistence computation.

Fields

matrix: Vec<Vec<u8>>

n_simplices: usize

Implementations

impl BoundaryMatrix

pub fn build(vr: &VietorisRipsComplex) -> Result<Self, PersistenceError>

Build the mod-2 boundary matrix from a Vietoris-Rips complex.

The columns are indexed by simplices (in the same order as vr.simplices), and rows are indexed by the simplices one dimension lower.

We use a dense representation for clarity: matrix[col][row] ∈ {0, 1}. For each column (a k-simplex), the rows with value 1 correspond to the (k−1)-faces of that simplex.

pub fn reduce(&mut self) -> HashMap<usize, usize>

Reduce the matrix using the standard algorithm. After reduction, column j is either zero or its lowest nonzero row low(j) is unique. Returns a mapping low -> j for non-zero reduced columns.

pub fn low(&self, j: usize) -> Option<usize>

Lowest nonzero row in column j, or None if the column is zero.

Trait Implementations

impl Clone for BoundaryMatrix

fn clone(&self) -> BoundaryMatrix

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BoundaryMatrix

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

Formats the value using the given formatter.