Crate spectrafit_models 

spectrafit-models — analytical model kernels with exact Jacobians.

Modules

asym_ir

Asymmetric IR band (Gaussian × logistic sigmoid).

breit_wigner

Breit-Wigner-Fano resonance.

cauchy_dispersion

Cauchy refractive-index dispersion (a + b/x² + c/x⁴).

doniach

Doniach–Šunjić asymmetric core-level lineshape (XPS).

emg

Exponentially-modified Gaussian (asymmetric tailing peak).

exp_over_linear

Exponential over a line (NIST StRD Chwirut1, Chwirut2): exp(−rate·x) / (den_const + den_lin·x).

exponential

Exponential decay and double-exponential models.

fano

Fano resonance lineshape model.

gaussian

Gaussian peak model with exact Jacobian.

gaussian2d

Axis-aligned 2-D Gaussian peak model (n_dims == 2). 2-D Gaussian kernel scaffold.

gaussian_nd

Axis-aligned N-D Gaussian peak model (parametric dimensionality). N-dimensional axis-aligned Gaussian kernel.

generalised_logistic

Generalised logistic / Richards curve (NIST StRD Rat42, Rat43): amplitude / (1 + exp(shift − rate·x))^(1/shape).

harmonic_ir

Driven damped harmonic-oscillator IR absorption.

kww

Kohlrausch–Williams–Watts stretched exponential (A·exp(−(x/τ)^β)).

log_normal

Log-normal peak (A·exp(−(ln(x/c))²/(2σ²)) for x > 0).

lorentzian

Lorentzian (Cauchy) peak model with exact Jacobian.

mgh09_rational

Kowalik–Osborne rational function (NIST StRD MGH09): amplitude · (x² + num_lin·x) / (x² + den_lin·x + den_const).

moffat

Moffat peak (A / (((x−c)/σ)²+1)^β).

pearson7

Pearson VII peak (A / [1 + ((x−c)/σ)²·(2^{1/m}−1)]^m).

polynomial

Constant and linear polynomial baseline models.

power_law_offset

Power-law with offset: amplitude · (offset + x)^(−1/shape) (Bennett5 model).

power_saturation

Power-law saturation: amplitude · (1 − (1 + rate·x/2)^(−2)) (Misra1b model).

pseudo_voigt

Pseudo-Voigt (Gaussian/Lorentzian mixture) model.

rational_cubic

Rational cubic over cubic, denominator constant pinned at 1 (NIST StRD Kirby2, Hahn1, Thurber): (a0+a1x+a2x²+a3x³) / (1+b1x+b2x²+b3x³).

saturating_exponential

Saturating exponential: amplitude · (1 − exp(−rate · x)) (BoxBOD model).

skewed_gaussian

Skewed Gaussian (error-function-modulated asymmetry).

split_gaussian

Split (asymmetric) Gaussian — different width each side (a.k.a. bi-Gaussian).

split_pearson7

Split Pearson VII (split width + exponent each side).

step

Step-function models: arctan, tanh, and erfc variants.

students_t

Student’s-t peak (A / (1+((x−c)/σ)²/ν)^((ν+1)/2)).

tauc

Tauc optical band-gap edge (A·((x−e_gap)·H(x−e_gap))^p).

voigt

Pseudo-Voigt linear-mixture model (the voigt/pseudo_voigt key).

voigt_true

True Voigt profile via the Faddeeva function (Gaussian ⊗ Lorentzian).

Traits

Model

Core model trait implemented by every built-in kernel.

Functions

all_model_types

Canonical list of every model-type string model_from_str can construct.

model_from_str

Dispatch a model type string to a boxed Model implementation.

model_from_str_with_dims

Dimension-aware model construction.