LSST DESC Core Cosmology Library (
CCL) provides routines to compute basic cosmological observables with validated numerical accuracy. The library is written in C99 and all functionality is directly callable from C and C++ code. We also provide python bindings for higher-level functions.
This software is a publicly released LSST DESC product which was developed within the LSST DESC using LSST DESC resources. DESC users should use it in accordance with the LSST DESC publication policy. External users are welcome to use the code outside DESC in accordance with the licensing information below.
The list of publicly released versions of this package can be found here. The master branch is the most recent (non-released) stable branch, but under development. We recommend using one of the public releases unless working on the development on the library.
Installation instructions can be found in INSTALL.md in this directory. Documentation for
CCL can be found:
- in DOC.md in this directory for an overview,
- in our wiki for a description of benchmarks and known installation issues,
- in the
CCLreadthedocs page for the
- by calling
help(function name)from within
- in the doxygen docs contained in the
docfolder within the repository for the C routines.
- There are also multiple examples in C, python and jupyter notebooks available in the
For known installation issues and further information on how CCL was benchmarked during development, see our wiki.
License, Credits, Feedback etc
This code has been released by DESC, although it is still under active development. When it reaches v1 status it will be accompanied by a journal paper that describes the development and validation of
CCL. You are welcome to re-use the code, which is open source and available under terms consistent with our LICENSE, which is a BSD 3-Clause license. If you make use of any of the ideas or software in this package in your own research, please cite them as "(LSST DESC, in preparation)" and provide a link to this repository: https://github.com/LSSTDESC/CCL. For free use of the
CLASS library, the
CLASS developers require that the
CLASS paper be cited: CLASS II: Approximation schemes, D. Blas, J. Lesgourgues, T. Tram, arXiv:1104.2933, JCAP 1107 (2011) 034. The
CLASS repository can be found in http://class-code.net. Finally, CCL uses code from the FFTLog package. We have obtained permission from the FFTLog author to include modified versions of his source code.