Installing PyCBC

Simple Installation

PyCBC is available through the PyPI. For straightforward use of the PyCBC library and executables, we recommend installing with the following command. If you are not running in a specialized computing environment, this is probably the appropriate thing to do.

pip install pycbc

Full Virtualenv for Development and Production

This document explains how to set up a virtual environment to install PyCBC either for development or use in a production analysis with a release. The code build will be a standard Python install, which requires that the installation directory containing the Python libraries is accessible at runtime.

PyCBC uses the fork and pull model for development. If you wish to develop PyCBC, then you will need an account on GitHub. Once you have set up your account you should follow the instructions to fork a repository to fork the gwastro/pycbc repository into your own account. From your own fork, you can follow the GitHub flow model to develop and maintain the code. For each new feature or bug fix, you should create a new branch to develop the feature. You can then create a pull request so that the PyCBC maintainers can review and merge your changes into the official repository.

Create a virtual environment for your development or production environment and do a clean install. The following will create a python3 environment: currently PyCBC requires python3.7 or higher.

virtualenv -p python3 env
source env/bin/activate
pip install --upgrade pip setuptools

We can then make a fresh clone of the repository.

git clone

Finally, install the most common pycbc develeopment environment packages as follows.

cd pycbc
pip install -r requirements.txt
pip install -r companion.txt
pip install .

Development build on LDG / IGWN clusters

The above instructions require some adjustment when working on a LIGO or other GW collaboration compute cluster (eg CIT). The main issue is that the default environment may not include a sufficiently recent python version (>=3.7). The standard workaround is to use a python executable available in a ‘IGWN Conda’ environment. To see what environments are available, you can run

conda info --envs

This should yield igwn-py37 as one choice. The output of this command will also tell you the location of the environment in the file system. Then, the location of the python3.7 executable is for instance /cvmfs/ and you will create the virtualenv via the command

virtualenv -p /cvmfs/ env

Once the virtualenv has been created you can install PyCBC from PyPI or a local copy with the [igwn] extra specifier to install the optional extra requirements recommended for IGWN users:

pip install -r requirements-igwn.txt
pip install .[igwn]

Other scenarios


For more details, including instructions on starting a docker container see:

Building the Documentation

To build the documentation from your virtual environment, first make sure that you have Sphinx and the required helper tools installed with

pip install "Sphinx>=1.5.0"
pip install sphinx-rtd-theme
pip install sphinxcontrib-programoutput

You can then build the documentation locally as

python build_docs

The documentation will show up locally in ‘docs/_build/html’.

Use of Intel MKL Optimized FFT libraries

PyCBC has the ability to use optimized FFT libraries such as FFTW and MKL. If MKL is the correct library for your platform, you can add the script that sets up the MKL environment to you virtualenv activate script with the command. Typically, the MKl source command appears as follows but may vary depending on your cluster / environment.

echo 'source /opt/intel/bin/ intel64'

Graphics Processing Unit support with CUDA

PyCBC has the ability to accelerate its processing using CUDA. To take advantage of this, follow the instructions linked below to install the CUDA dependencies.