Struct CheckpointSegment 

pub struct CheckpointSegment {
    pub name: String,
    pub weights: Vec<f32>,
    pub in_dim: usize,
    pub out_dim: usize,
}

A recomputable segment: stores weights and dimensions so the forward pass (matrix-vector product y = W * x) can be re-executed cheaply.

Unlike the generic LinearSegment + Recomputable approach, this is a self-contained struct that carries everything needed for recomputation.

Fields

name: String

Human-readable name for this segment (e.g. "layer_3").

weights: Vec<f32>

Row-major weight matrix of shape [out_dim, in_dim].

in_dim: usize

Input dimension.

out_dim: usize

Output dimension.

Implementations

impl CheckpointSegment

pub fn new( name: impl Into<String>, weights: Vec<f32>, in_dim: usize, out_dim: usize, ) -> Self

Create a segment with explicitly provided weights.

pub fn init_lcg( name: impl Into<String>, in_dim: usize, out_dim: usize, seed: u64, ) -> Self

Create a segment with LCG-initialised weights (no rand crate).

Uses the Knuth MMIX LCG constants. Weights are mapped to [-1, 1].

pub fn forward(&self, input: &[f32]) -> Result<Vec<f32>, CheckpointError>

Forward pass: compute y = W * x (matrix-vector product).

input must have exactly in_dim elements. Returns a vector of out_dim elements.

pub fn activation_memory(&self) -> usize

Memory (in bytes) required to store one full activation (output).