This page has instructions on installing OPS, installing software packages that integrate with OPS, and testing that your OPS installation is working.
OpenPathSampling currently only works on POSIX systems (macOS and UNIX/Linux). It is tested against Python 2.7, 3.7, 3.8, and 3.9.
OpenPathSampling can be installed with
pip, or by using
setuptools. We recommend using
conda because it provides easy
installation of other tools, including molecular dynamics engines such as
OpenMM and GROMACS, which most users will want to install when using OPS.
Conda can be installed either with the full Anaconda distribution, or with
the smaller-footprint miniconda.
OpenPathSampling can be installed from the
conda-forge channel. To
install the most recent release, use the command
$ conda install -c conda-forge openpathsampling
With that, you should be ready to use OPS!
OPS can also be installed with
pip via the command
python -m pip install
openpathsampling, or the source can be downloaded and installed using
setuptools and the command
python setup.py install (run from the
root directory of the source repository). We only recommend these
installation mechanisms for users who are familiar with these tools.
OpenPathSampling can be installed as an “editable” (developer) install
through standard mechanisms (
python -m pip install -e . or
Additionally, we provide a script that downloads the OPS source repository,
conda to install OPS’s requirements (including several optional
integrations) and the installs OPS. Details on using this script are in
Quick bugfix/developer installation.
Integration with other packages
When you install OpenPathSampling, you only get the core of OPS and the internal toy dynamics engine. In practice, you’ll probably want a more powerful MD engine like OpenMM or GROMACS.
To add support for optional packages, all you need to do is install them. For example, simply by having OpenMM or GROMACS installed on your system, you will automatically have support for those engines within OPS.
The tables below list several packages that provide OPS with extra
functionality when installed, and include links to their
Molecular dynamics engines
OPS has special support for integrators from OpenMMTools (and we strongly recommend using one of the reversible integrators provided there, such as VVVR).
OPS will work with any installed GROMACS; it
does not need to come from
In addition to the optional packages listed below, OPS ships with MDTraj built-in.
Testing your installation
OpenPathSampling includes a thorough test suite, and running the test suite
is a good start to troubleshooting any installation problems. The OPS test
suite requires the packages
pytest and (for legacy reasons)
These can be installed with either
pip. For example:
$ conda install pytest nose
Once those are installed, you can run the test suite on your installation with the command:
$ py.test --pyargs openpathsampling.tests
The test suite includes over 1100 individual tests, and runs in around 2-3 minutes. All tests should either pass or skip.