Welcome to Vega’s documentation!

Vega is a tool for computing 3D correlation function and power spectrum models primarily for Lyman-α (Lyα) forest analyses. It is built to be modular and highly flexible in terms of the tracers being used. So far, Vega has been used to analyze the Lyα forest auto-correlation, its cross-correlation with galaxies and quasars (e.g., Gerardi et al. 2022, Gordon et al. 2023, Herrera-Alcantar et al. 2025, Karaçaylı et al. 2026), as well as auto- and cross-correlations of metal lines such as CIV and SiIV (e.g., Guy et al. 2025, Bault et al. 2026), Damped Lyman-α (DLA) absorbers (Pérez-Ràfols et al. 2023), and Strong Blended Lyman-α (SBLA) absorbers (Pérez-Ràfols et al. 2023).

Vega is currently being used by the Lyα forest working group in DESI to measure Baryon Acoustic Oscillations (BAO) and perform full-shape analyses of Lyα forest auto- and cross-correlations (e.g., DESI et al. 2025a, DESI et al. 2025b, Cuceu et al. 2025).

• Free software: GPL-3.0-or-later License

• Documentation: https://vega.readthedocs.io.

• Referencing: If you use Vega in a publication, please give the link to this repository (andreicuceu/vega). The best descriptions of what the code does are found in Cuceu et al. (2022) and Cuceu et al. (2025).

• Introduction
  • Installation
  • Installing Polychord
  • Usage
  • Using the terminal
  • Interactive use
  • Credits
• Installation
• Installing Polychord

There are several tutorials and examples available to help you get started with Vega:

Tutorials & Examples:

• Old Vega Tutorial
• Simple Model Tutorial
• Fit Results Tutorial
• Vega Plots Module
• Old Plots Tutorial
• Vega Plots 2 Datasets
• Config Creation
• Sensitivity Tutorial

Vega modules are documented here:

• Vega Modules
  • VegaInterface
  • BuildConfig
  • FitResults
  • CorrelationItem
  • Data
  • Model
  • CorrelationFunction
  • PowerSpectrum
  • ScaleParameters
  • Coordinates
  • PktoXi
  • Metals
  • BroadbandPolynomials
  • Analysis
  • Minimizer
  • Output
  • VegaArinyoError
  • VegaBoundsError
  • VegaModelError
  • apply_blinding()
  • bias_beta()
  • compute_gauss_smoothing()
  • compute_kn_smoothing()
  • compute_log_cov_det()
  • compute_masked_invcov()
  • convert_instance_to_dictionary()
  • find_file()
  • get_growth_interp()
  • get_legendre_bins()
  • growth_function()
  • growth_integrand()
  • hubble()
  • normalized_growth_factor()
  • percival_correction()
  • sinc()
  • VegaPlots
  • Shell
  • Wedge
  • RtWedge
  • array_or_dict()
  • plot_wedges()
  • Sampler
  • Polychord
  • build_names()
  • get_default_values()
  • get_latex()

Other stuff:

• Contributing
• Credits
• History
• Some parameter descriptions (old)

Indices and tables

• Index

• Module Index

• Search Page