Section: Software

CULT, the Computational Unified Library for Topology

Participants : Jean-Daniel Boissonnat, Frédéric Chazal, Arijit Ghosh, Marc Glisse, Samuel Hornus, Steve Oudot, Primoz Skraba.

With the collaboration of Gunnar Carlsson Vin de Silva, Leonidas Guibas, Dmitriy Morowov, and Michael Vejdemo-Johansson. http://gforge.inria.fr/projects/cult

Since April 2009, Geometrica has been part of a joint effort with the Geometric Computation and Applied Topology groups at Stanford University to develop the successor of the PLEX library, now considered a standard in computational topology. The new library, named cult (Computational Unified Library for Topology), will offer a vast set of tools that reflects the state of the art in the field. It should be able to handle very large and high-dimensional data sets within reasonable amount of time and space, while keeping enough flexibility for people to be able to build their own algorithms upon it. Potential interactions with other libraries like cgal will also be investigated.

Making the library effective will require a lot of work on designing new data structures whose complexities scale up reasonably with the size and dimensionality of the input data. Usually, people have to deal with complexes containing dozens of millions of simplices. Such complexes do not fit into main memory, at least with a naive data representation. On the other hand, brute-force compression of the data results in prohibitively slow access times. A trade-off between space and time needs to be found, which will be one of the research topics of Geometrica for 2010.