Changelog#

[2.0.1] - 2026-04-21#

Feature: Added “Equalize and Stitch” to the GUI with dynamic parameters.
Fix: Prevented FITS save crashes from Ly-α identifications and ensured tooltips render safely upon reloading.

Added an experimental Bayesian fitting engine supporting MCMC (emcee).
Introduced interactive Corner Plots to visualize Bayesian posteriors with asymmetric uncertainties and auto-refresh capabilities.
Fixed a critical group definition bug to ensure physically linked components are always correctly grouped during fitting.
Improved continuum fitting and smoothing methods, including dynamic re-normalization of the Voigt model.
Polished the GUI with publication-ready plot formatting, stacked asymmetric error labels, and scientific notation for redshift uncertainties.
Finalized the transition to the immutable V2 data architecture and removed legacy dead code.

Improved robustness (crash recovery) and fitting (weak lines, Lyman forest)
Updated line lists (FeII, SiII, etc.) and set turbulent broadening (btur) to default to frozen.
Added batch actions (refit, freeze, delete), group highlighting, and visual feedback for frozen parameters
Introduced a Data Inspector and a recipe to equalize flux across sessions
Added Drag-and-Drop support to the main window

More flexible way to manually edit continuum
More robust fitting engine (when parameters hit boundary values)
More options in adding/fitting components (single doublet component; stop button for refitting)
Optional refitting of systems upon import into a session

Includes

a fully redesigned architecture, with immutable structures and exposed APIs;
a new PySide6 QUI
countless improvements to the V1 algorithms and new algorithms (especially for continuum and absorber fitting)

Also downloadable as a macOS App.