Repack and compress line-transition data
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Re-pack and Compress Line-transition Data for Ratiative-tranfer Calculations

This code identifies the strong lines that dominate the spectrum from the large-majority of weaker lines. The code returns a binary line-by-line (LBL) file with the strong lines info (wavenumber, Elow, gf, and isotope ID), and an ascii file with the combined contribution of the weaker lines compressed into a continuum extinction coefficient (in cm-1 amagat-1) as function of wavenumber and temperature.

Currently available databases:

Table of Contents

Team Members

Install and Compile

repack is compatible with both Python2 and Python3, and runs (at least) in both Linux and OSX.
To obtain the repack code, clone this repository to your local machine with the following terminal commands:

# Clone the repository to your working directory:  
git clone

# Compile the C-extensions of the program:
cd repack

Getting Started

The following script processes the Exomol HCN line-transition data. Returning a LBL and continuum files with compressed info.

# Go to the repositoy demo folder:
cd demo/
# Download and uncompress Exomol HCN data:
wget -i wget_exomol_hcn.txt
bzip2 -d *.bz2

# Call the repack command-line executable for the HCN demo config file:
../ repack_HCN.cfg


  • The input configuration file specifies the wavenumber and temperature sampling arrays, the input files, and the line-intensity threshold.
  • The binary LBL output file contains the wavenumber (in cm-1), energy of the lower state (in cm-1), the gf value, and the isotope index, encoded as three doubles and one integer, storing the info for each line after the other.
  • The ascii continuum output file contains the extinction-coefficient data (in cm-1 amagat-1) as function of wavenumber and temperature.

Be Kind

Please, be kind and acknowledge the effort of the authors by citing the article asociated to this project:

Cubillos (2017): An Algorithm to Compress Line-transition Data for Radiative-transfer Calculations, ApJ 850, 32.


Copyright (c) 2017-2018 Patricio Cubillos and contributors. repack is open-source software under the MIT license (see LICENSE).