Struct AllanVarianceEstimator 

pub struct AllanVarianceEstimator<const N: usize> { /* private fields */ }

Rolling Allan variance estimator.

Maintains a circular buffer of N phase/norm samples and computes σ_y(τ) for each of the ALLAN_TAUS averaging intervals using the overlapping Allan variance formula:

σ²_y(τ) = 1 / (2τ²(N-2τ)) · Σ_{k=1}^{N-2τ} [x(k+2τ) - 2x(k+τ) + x(k)]²

Type Parameters

• N: Buffer capacity (≥ 256 recommended for τ=128 support; 512 is ideal).

Implementations

impl<const N: usize> AllanVarianceEstimator<N>

pub const fn new() -> Self

Create a new estimator with empty buffer.

pub fn push(&mut self, sample: f32)

Absorb one sample (residual norm or phase increment).

pub fn len(&self) -> usize

Number of valid samples.

pub fn is_ready(&self) -> bool

Whether enough samples are available for fingerprint computation. Requires count ≥ 2 * max_tau + 1 = 257 for τ_max = 128.

pub fn allan_deviation(&self, tau: u32) -> f32

Compute Allan deviation σ_y(τ) for averaging time τ (in samples).

Uses overlapping samples for N_eff = count − 2τ averages. Returns 0.0 if count < 2τ + 1.

pub fn fingerprint(&self) -> Option<[f32; 8]>

Compute the 8-element Allan deviation fingerprint.

Returns None if is_ready() is false.

pub fn reset(&mut self)

Reset the buffer.

Trait Implementations

impl<const N: usize> Default for AllanVarianceEstimator<N>

fn default() -> Self

Returns the “default value” for a type.