Struct Fano 

pub struct Fano;

Fano resonance lineshape used in XPS asymmetric peaks.

Formula: A · (q + ε)² / (1 + ε²), ε = (x − x₀) / Γ

Parameters (in order): [amplitude, center, gamma, q]

• amplitude — overall scale factor A
• center — resonance centre x₀
• gamma — half-width at half-maximum Γ (> 0)
• q — Fano asymmetry parameter (dimensionless)

Jacobians are fully analytical.

Trait Implementations

impl Model for Fano

fn eval(&self, x: &[f64], params: &[f64]) -> f64

Evaluate the model at coordinate x with the given params.

fn jacobian(&self, x: &[f64], params: &[f64]) -> Vec<f64>

Jacobian — one derivative per parameter, in the same order as param_names().

fn jacobian_into(&self, x: &[f64], params: &[f64], out: &mut [f64])

Fill a pre-allocated slice with Jacobian values (one entry per parameter).

fn param_names(&self) -> Vec<Cow<'static, str>>

Ordered parameter names, matching the layout expected by eval and jacobian.

fn eval_slice_into(&self, xs: &[f64], params: &[f64], out: &mut [f64])

Batch evaluation of a 1-D model: fill out[i] = eval([xs[i]], params).

fn jac_slice_into(&self, xs: &[f64], params: &[f64], out: &mut [f64])

Batch Jacobian for a 1-D model: fill out in row-major layout [i * params.len() + j] = d(model)/d(params[j]) at xs[i].

fn n_dims(&self) -> usize

Number of coordinate dimensions consumed from x. Defaults to 1.