pyhola

This project wraps a key part of the adaptagrams c++ library using pybind11. Specifically, it wraps the HOLA algorithm (Human-like Orthogonal Layout Algorithm) in libdialect: a very promising graph layout algorithm which approximates to what a human would do if the given the task to layout a graph. Further details are provided in this paper.

The HOLA algorithm is part of the libdialect module of the adaptagrams library.

Note that the the adaptagrams library provides a comprehensive swig-based python wrapper which is likely useful for most use-cases.

This project provide a targeted pybind11 wrapper for the HOLA algorithm, and tries to provide a pythonic api along the way. There is also a nanobind wrapper in development which is still not functional.

pyhola and the adaptagrams swig-based python wrapper have been used successfully in the py2max project, to provide auto-layout capability of programmatically generated Max patches.

To build pyhola:

make

Status

• HOLA algorithm in pyhola_pybind11 build is functional other builds, pyhola_bind (generated) is not functional.

Usage

You will need pybind11 installed:

pip install pybind11

Then use the included Makefile to compile the pybind11 extension.

make

to test (requires pytest)

make test

or

pytest

to clean the test output:

make clean

The compiled static lib files (compiled on 64bit macOS Catalina) and include files for the adaptagrams library are only included for convenience.

You can compile your own more recent libs and just drop them into this project.

Future Directions:

• Wrap all of adaptagrms libs: after manually wrapping the core HOLA algorithm, there is an ongoing effort to use binder (see below) to wrap the whole of the adaptagrams libs automatically. While a decent portion is wrapped, there are still a few errors which remain. (see bind/remaining-errors.diff)

Binder Usage

To use binder, a tool to autogenerate pybind11 bindings for c++ code, build it and use the resulting binary to generate code which can then be manually fixed and tweaked to supplement the current pyhola library.

To build and test binder

1. brew install cmake ninja pybind11

2. build binder using the build.py script in the binder repo. Ignore the documentation since it has dated installation instructions.

3. copy or move the resulting build binder directory to ~/.binder and symlink as follows: ~/.binder/bin/binder to /usr/local/bin/binder

4. run ./build.sh in this directory and a demo python extension should be in the build directory

Credits and Licensing

All rights reserved to the original respective authors:

Steve Kieffer, Tim Dwyer, Kim Marriott, and Michael Wybrow. HOLA: Human-like Orthogonal Network Layout. In Visualization and Computer Graphics, IEEE Transactions on, Volume 22, Issue 1, pages 349 - 358. IEEE, 2016. DOI

Thanks to Wenzel Jakob, developer of pybind11 and nanobind for making this project possible.

This thin pybind11 wrapper is placed in the public domain.