Struct SpectrumFitResult 

pub struct SpectrumFitResult {

    pub densities: Vec<f64>,
    pub uncertainties: Option<Vec<f64>>,
    pub reduced_chi_squared: f64,
    pub converged: bool,
    pub iterations: usize,
    pub temperature_k: Option<f64>,
    pub temperature_k_unc: Option<f64>,
    pub anorm: f64,
    pub background: [f64; 3],
    pub back_d: Option<f64>,
    pub back_f: Option<f64>,
    pub t0_us: Option<f64>,
    pub l_scale: Option<f64>,
    pub deviance_per_dof: Option<f64>,
}

Result of fitting a single spectrum.

Fields

densities: Vec<f64>

Fitted areal densities (atoms/barn), one per isotope.

uncertainties: Option<Vec<f64>>

Uncertainty on each density.

None when covariance computation was skipped.

reduced_chi_squared: f64

Reduced chi-squared of the fit.

converged: bool

Whether the fit converged.

iterations: usize

Number of iterations.

temperature_k: Option<f64>

Fitted temperature in Kelvin (only when fit_temperature is true).

temperature_k_unc: Option<f64>

1-sigma uncertainty on the fitted temperature (from covariance matrix).

anorm: f64

Fitted normalization scale (SAMMY Anorm). When background fitting is disabled, the pipeline emits 1.0 (memo 35 §P1 convention — λ̂ absorbs the scale).

background: [f64; 3]

Fitted background polynomial coefficients [BackA, BackB, BackC] for the SAMMY-style 6-term background:

bg(E) = BackA + BackB / √E + BackC · √E + BackD · exp(-BackF / √E)

Both LM-transmission and counts-KL solver paths use the same SAMMY semantics here — the legacy alpha-fitting [b0, b1, alpha_2] layout was removed when fit_counts_poisson was retired in PR #450. When background fitting is disabled, the pipeline emits [0.0, 0.0, 0.0].

back_d: Option<f64>

Fitted exponential background amplitude (SAMMY BackD). None when the exponential tail is not fitted; Some(value) when the LM transmission background was active with fit_back_d=true. Mirrors Self::t0_us / Self::l_scale semantics so the GUI overlay can distinguish “unfit” from “fitted to zero” without an ambiguous 0.0 sentinel.

back_f: Option<f64>

Fitted exponential background decay constant (SAMMY BackF). None when the exponential tail is not fitted; Some(value) when the LM transmission background was active with fit_back_f=true. Paired with Self::back_d — SAMMY requires both flags toggled together (see validate_transmission_background).

t0_us: Option<f64>

Fitted TOF offset in microseconds (SAMMY TZERO t₀). None when energy-scale fitting is not enabled.

l_scale: Option<f64>

Fitted flight-path scale factor (SAMMY TZERO L₀, dimensionless). None when energy-scale fitting is not enabled.

deviance_per_dof: Option<f64>

Conditional binomial deviance divided by (n − k) (memo 35 §P1.2 — primary GOF for the counts-KL dispatch, i.e. SolverConfig::PoissonKL on InputData::Counts or InputData::CountsWithNuisance).

Some(D/dof) when the counts-KL (joint-Poisson) path was used; None for the LM path and for transmission + PoissonKL (those populate reduced_chi_squared with Pearson χ² / (n−k) instead).

Trait Implementations

impl Clone for SpectrumFitResult

fn clone(&self) -> SpectrumFitResult

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SpectrumFitResult

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

Formats the value using the given formatter.