General Instructions

Instructions and Notebooks Specific to Data Set

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Install and Configure GCRCatalogs

You can install GCRCatalogs with conda or pip, depending on your local Python environment.

Install with conda


Before installation, you may want to create a new conda environment. If you do, see instructions here.

GCRCatalogs is available on conda-forge, not on conda’s “defaults” channel. If you are using the “defaults” channel (for example, if you haven’t heard of conda-forge), you can still install GCRCatalogs directly using the instruction below. However, please consider switching to the conda-forge channel; see instructions and why.

NOTE: In order to access the latest catalogs (as of June 2022) you need GCRCatalogs version v1.4.0 or later. When using either of the install methods described below you will get a suitable released version. If you have already installed GCRCatalogs for an earlier data release, you can update instead.


To install GCRCatalogs with conda, run

conda install -c conda-forge lsstdesc-gcr-catalogs


To update with conda, run

conda update -c conda-forge lsstdesc-gcr-catalogs

Install with pip


Before installation, you may want to create a new virtual environment. If you do, see instructions here.

You may want to first install wheel, which will allow pip to fetch pre-built binary files. To install wheel, run

pip install wheel  # optional


To install GCRCatalogs with pip, run

pip install[full]


To update with pip, use the --upgrade option:

pip install --upgrade[full]

Configure: Setting up root_dir for GCRCatalogs

After you download the data files and install GCRCatalogs, you need to tell GCRCatalogs where these downloaded files sit on your machine.

When you used Globus transfer, if you downloaded the files to /path/to/the/download/directory, then run in a terminal

python -m GCRCatalogs.user_config set root_dir /path/to/the/download/directory

Here /path/to/the/download/directory should contain the lsstdesc-public folder that Globus transfer creates. If you have moved it, you should change /path/to/the/download/directory to the directory that contains the lsstdesc-public folder. Do not change the directory structure within lsstdesc-public.

You only need to set this once.

Checking that everything is ready

You can use the following Python code to check if you have GCRCatalogs installed and root_dir correctly set.

import GCRCatalogs

To see the list of public catalogs that may be available to you, run:


Note that the above function returns the list of public catalogs that DESC has published, but it does not check if those catalog files exist on your machine. You will need to download them manually following these instructions.

To confirm that GCRCatalogs has access to the files you’ve downloaded see the specific instructions for either cosmoDC2 or the DC2 Simulated Sky Survey.