flagser

Copyright © 2017–2021 Daniel Lütgehetmann.

Description

flagser computes the homology of directed flag complexes. For a more detailed description consult the documentation under docs/documentation_flagser.pdf.

Building

Flagser requires a C++14 compiler and cmake. Here is how to obtain, build, and run flagser:

git clone git@gitlab.com:luetge/flagser.git
cd flagser
(mkdir -p build && cd build && cmake .. && make -j)
./test/run

Running

To call flagser you run

./flagser --out example.homology test/medium-test-data.flag

For more detailed instructions, see docs/documentation_flagser.pdf.

You can run flagser with the argument --in-memory which changes flagser internals storing the full directed flag complex in memory, speeding up parts of the computation but requiring more memory.

Included in this package is also the original program ripser, modified only in that the features of flagser are supported.

Euler characteristic and cell counts

To only compute the Euler characteristic and cell counts, run

./flagser-count example.flag

Online Version

An online version is available here (thanks to JasonPSmith): https://homepages.abdn.ac.uk/neurotopology/flagser.html

License

flagser is licensed under the MIT license (COPYING.txt), with an extra clause (CONTRIBUTING.txt) clarifying the license for modifications released without an explicit written license agreement. Please contact the author if you want to use Ripser in your software under a different license.