← Algorithms · Parametric sphere mixture

Parametric sphere mixture

Purpose. When D(R) or I(q) suggests one or more spherical populations, a parametric mixture (mean radii, polydispersities, volume fractions) is a compact physical model — easier to interpret than a free D(R) alone, and useful for comparing samples.

Engine. ATSAS MIXTURE fits hard-sphere populations. Autosaxs decides which models to try and which fit wins.

What autosaxs adds (custom).

1. Runs a fixed grid over phase count (up to max_nph, default 3) and size-distribution families (Gauss / Schultz) for SPHERE phases.
2. Applies careful initialization (e.g. radius / polydispersity bounds; defaults for r_max often taken from fit_sizes when unset).
3. Selects the preferred model by minimizing BIC_log (Bayesian information criterion on the log-intensity fit), balancing goodness-of-fit against extra phases.
4. Writes comparison plots and a results table so you can inspect runners-up, not only the winner.

Enable MIXTURE in the polydisperse window when you want this step after D(R); it is optional.

← D(R) · Geometric bodies →