Struct Graph 

pub struct Graph<F: SemiflowFloat = f64> { /* private fields */ }

Frozen sparse weighted graph in symmetric CSR layout. See ADR-0048.

Immutable post-construction — no mutator methods. Invariants I1–I7 hold.

Implementations

impl<F: SemiflowFloat> Graph<F>

pub fn n_nodes(&self) -> usize

Number of nodes. O(1).

pub fn n_directed_edges(&self) -> usize

Number of directed edge-entries stored (= 2 · undirected_edges).

pub fn row_ptr(&self) -> &[usize]

Row-pointer slice. Length n_nodes + 1.

pub fn col_idx(&self) -> &[u32]

Column-index slice (neighbour node ids).

pub fn vals(&self) -> &[F]

Edge-weight slice (same length as col_idx).

pub fn path(n: usize) -> Self

Path graph 0 — 1 — 2 — … — (n − 1) with unit edge weights.

Panics

Panics if n == 0.

pub fn cycle(n: usize) -> Self

Cycle graph: path graph plus edge (n − 1) — 0, all unit weights.

Panics

Panics if n < 3 (cycle on 1 or 2 nodes is degenerate).

pub fn from_edges( n_nodes: usize, edges: impl IntoIterator<Item = (u32, u32, F)>, ) -> Result<Self, SemiflowError>

Build from an iterator of undirected edges (u, v, w).

Errors

SemiflowError::DomainViolation: self-loop, node out of range, bad weight, duplicate edge, or a weighted degree dᵢ that overflows to ∞ (it is the combinatorial Laplacian’s diagonal entry).

pub fn erdos_renyi(n_nodes: usize, p: f64, seed: u64) -> Self

Erdős–Rényi G(n_nodes, p) with seeded splitmix64 RNG. All weights = 1.