Welcome to PSyclone. PSyclone is a code generation system that generates appropriate code for the PSyKAl code structure developed in the GungHo project.

Please see psyclone.pdf in this directory (or on ReadTheDocs) for more information. If you would prefer to build the documentation, please see the README file in the "doc" directory.

Try it on Binder

Some of the examples are available as Jupyter notebooks. These may be launched using Binder from the links below. (Note that the first time this is done, Binder has to construct a Container and install the necessary software. This can take several minutes. You can track its progress by clicking the 'show' link next to the 'Build logs' heading.)


Uses PSyclone's NEMO API to process some simple Fortran code, display the resulting PSyIR and then re-generate Fortran.


Uses PSyclone's GOcean API to process example code that conforms to the PSyKAl separation of concerns. Transformations are applied in order to fuse various loops before parallelising the result with OpenMP.


demonstrates the generation of a DAG for the PSy layer of the previous example.


The PSyclone tutorial may be found in the tutorial directory. Since part of this takes the form of a series of Jupyter notebooks, it too may be launched on




If you are reading this then you have presumably not already installed PSyclone from the Python Package Index ( That being so, you can install this copy of PSyclone by doing:

$ python install

or, if you do not have root access:

$ python install --prefix /my/install/path

Alternatively, if you have pip:

$ pip install .

For a user-local installation simply add the --user flag:

$ pip install --user .

This installs the PSyclone modules in ~/.local/lib/pythonX.Y/site-packages (where X.Y is the version of Python that you are using) and the 'psyclone' script in ~/.local/bin. Depending on your linux distribution, you may need to add the latter location to your PATH.


bin/top-level driver scripts for PSyclone and the Kernel stub generator
changelogInformation on changes between releases
doc/Documentation source using sphinx
examples/Simple examples
psyclone.pdfGenerated documentation
README.mdThis file
README.gourceInformation on how to generate a gource video from the repository
README.umlInformation on how to create UML class diagrams from the source using pyreverse
src/psycloneThe python source code
src/psyclone/tests/Unit and functional tests using pytest
tutorial/notebooksTutorial using Jupyter notebooks
tutorial/practicalsHands-on exercises using a local installation of PSyclone


Build Status
GitHub - stfc/PSyclone: Domain-specific compiler for Finite Difference/Volume/Element Earth-system models in Fortran
Domain-specific compiler for Finite Difference/Volume/Element Earth-system models in Fortran - GitHub - stfc/PSyclone: Domain-specific compiler for Finite Difference/Volume/Element Earth-system mod...