Installing lalsuite for PyCBC

The following page describes how to build lalsuite from source for use with PyCBC.


These instructions assume that you already have the required dependencies for lalsuite installed on your system. You must have git, FFTW, GSL, FrameL, and MetaIO installed before continuing.

These packages are installed by default on a LIGO Data Grid cluster. If you are not on a LIGO Data Grid cluster, see the lalsuite install instructions for instructions on installing/building the dependencies. You can also contact your system administrator to determine if these packages are available.

Obtaining the source code and checking out a version

In your virtual environment, make a directory for the lalsuite source. Enter your virtual environment with the command

source ~/src/pycbc/bin/activate

changing the path to the activate script appropriately. Clone the lalsuite repository into the directory ${VIRTUAL_ENV}/src/lalsuite by running the commands

mkdir -p ${VIRTUAL_ENV}/src
cd ${VIRTUAL_ENV}/src
git clone

Note that this checks out a read-only repository. If you want a git repository that you can edit, you can either fork this repository to your own GitHub account or, if you have LIGO.ORG credentials, you can follow the instructions on the LSC Computing pages for cloning lalsuite.


Since building lalsuite is very disk intensive, you may want to store the lalsuite git repository on a local disk rather than an NSF-mounted directory. If this is the case, change the path in the mkdir and cd above to a directory on a non-NFS mounted filesystem. This is not required, as lalsuite will build on an NFS disk, it is just slower.

Once you have the repository cloned, you should change your working directory to the top-level of the repository with

cd ${VIRTUAL_ENV}/src/lalsuite

Now determine which version of the code you want to install. To run the latest (possibly unstable) version of the code, use the master branch by running the command:

git checkout master

If you want to build a specific release, replace master with a release tag, for example lalsuite-v6.30. See the list of lalsuite tags for available tags. You can also check out a branch from the list of lalsuite branches in the same way; replace master with the branch name, e.g. lalsuite_o1_branch. Once you have checked out a tag or a branch, you can build and install lalsuite.

Building and installing into your virtual environment


The install instructions below install lalsuite into a directory called opt/lalsuite under your virtual environment. You can remove lalsuite by removing this directory with rm -rf ${VIRTUAL_ENV}/opt/lalsuite from inside your virtual environment. If you want to install multiple versions of lalsuite in your virtual environment, you can chose different directories by specifying a different --prefix to configure below.

First make sure you are in your virtual environment by activating it. If you are not already in your virtual environment run the command

source ~/src/pycbc/bin/activate

changing the string ~/src/pycbc appropriately to point to your environment.

From the top-level lalsuite directory, you can use the master configure script to build and install all of the components that you need with the commands

./configure --prefix=${VIRTUAL_ENV}/opt/lalsuite --enable-swig-python --disable-lalstochastic --disable-lalxml --disable-lalinference --disable-laldetchar --disable-lalapps


The configure command above does not build lalapps executables, which include some template bank generation codes, and lalapps_inspinj and lalapps_coh_PTF_inspiral which are currently used in search pipelines. To instead build lalapps executables, run the configure command without the disable-lalapps option.

Next make the software and install it. If you are on a multicore machine, you can speed this up by running make -j N where N is the number of processors you want to use for the build (e.g. 16). To use the maximum number of processors, run make -j. (This may not be appropriate on shared machines, e.g. LDG head nodes.)

make install

The install process creates a shell script called that sources all of the ${VIRTUAL_ENV}/opt/lalsuite/etc/lal* scripts that set up the environment for lalsuite. You can add this to your virtualenv activate script so that it gets set up when you enter your virtual environment. To do this, run the commands

echo 'source ${VIRTUAL_ENV}/opt/lalsuite/etc/' >> ${VIRTUAL_ENV}/bin/activate

You can reenter your virtual environment with the usual command

source ~/pycbc/src/bin/activate

changing ~/pycbc/src as appropriate for your virtual environment path.


If you want to manage multiple versions of lalsuite, it is not recommended to source the script in your activate script. Instead, you should explicitly source the lalsuite install corresponding to your pycbc build after entering your virtual environment, with the command source ${VIRTUAL_ENV}/opt/lalsuite/etc/

lalsuite is now installed in your virtual environment. You can check this with the command


which should return the path to the installation under your virtual environment.

Additional data files from lalsuite-extra

In addition to lalsuite, the generation of certain template waveforms (e.g. the reduced order model implementations of SEOBNRv2 and SEOBNRv4) requires data files from the lalsuite-extra repository. These data can either be obtained by downloading and installing lalsuite-extra into your virtual environment or using a copy of the data from the CERN virtual filesystem.

To install the data into your virtual environment, run the commands

cd ${VIRTUAL_ENV}/src
git clone
cd lalsuite-extra
./configure --prefix=${VIRTUAL_ENV}/opt/lalsuite-extra
make install
echo 'export LAL_DATA_PATH=${VIRTUAL_ENV}/opt/lalsuite-extra/share/lalsimulation' >> ${VIRTUAL_ENV}/bin/activate

Then deactivate and activate your virtual environment.

Alternatively, follow the instructions for installing CVMFS for OSG and run the command

echo 'export LAL_DATA_PATH=/cvmfs/' >> $VIRTUAL_ENV/bin/activate

to add the appropriate path to your virtual environment’s activate script. Then deactivate and activate your virtual environment.