Upgrading from the previous CosmoSIS Version

You may have used the old CosmoSIS version that was hosted on BitBucket.org.

There are a few changes you need to make for the new version.

Repositories

The old version of CosmoSIS expected you to download both the main cosmosis repository and the cosmosis-standard-library. Now you only download the standard library, unless you are working on a new sampler.

See the instructions on the installation page for details.

Module paths

In the old CosmoSIS you usually had to specify the file parameters in your main parameter file starting with $COSMOSIS_SRC_DIR/cosmosis-standard-library/. You would now typically run chains from the standard library directory and remove that prefix. If you were running from a different directory you would use the path to the standard library as the root parameter in the [runtime] section.

Camb & Halofit

The CAMB module has been replaced with one which uses the camb python package. A few parameter names have changed - see the new camb module reference for a full listing.

Additionally, the Halofit modules that were previously separate are now accessed directly through camb.

Two-Point Calculations

The project_2d module for calculating the 2D power spectra C_ell has been upgraded. You can mostly use it as you did before, but the parameters n_ell, ell_min and ell_max should now be n_ell_logspaced ell_min_logspaced and ell_max_logspaced instead. There are also many additional options available now to compute other combinations including biased galaxy samples and non-Limber values.

See the project_2d reference for more details, or see the DES-Y3 example.