welcome
GraPHedron is a research project originated in a collaboration between:
Institute of Computer Science, Université de Mons-Hainaut
Department of Computer Science, Université Libre de Bruxelles
Both universities are members of the Académie Wallonie-Bruxelles.
GraPHedron is a computer-assisted system which helps to obtain conjectures in graph theory. It uses a polyhedral approach to find strongest relations among graph invariants. This approach provides a formal framework allowing to identify interesting and tight relations.
If it is your first visit, please learn the basics of GraPHedron to understand what it can do, in order to help you in your graph theory research. Otherwise, please log in and start to work with GraPHedron.
Latest news
Friday 03 July 2009: Algebraic expression of invariants
The use of algebraic expressions of invariants to define coordinates and conditions was limited to the console version of GraPHedron. It is no more the case: you can now use them also via the website.
Saturday 18 April 2009: Reopening of GraPHedron
The GraPHedron web site was closed due to an hardware failure. Hopefully, all databases were restored. However, your old projects should be recomputed if you need the reports again. It can be easily done in your existing projects page. Also, some invariants are not yet available since the server is currently computing them.
Friday 26 October 2007: The paper explaining the principles of GraPHedron is available
The paper Facet defining inequalities among graph invariants: the system GraPHedron to appear in Discrete Applied Mathematics is now available online. You can download it via ScienceDirect.
Notice
This web portal of GraPHedron allows you to
use a specific version of the system. There are some differences between this
version and the console
version of GraPHedron:
- All graphs and invariants data are precomputed. It means that solving a problem is more fast but it implies that the usable data must be already computed. The GraPHedron server is continuously computing new data which are then added to the available classes of graphs and invariants.
- All
console
options are not available at this time. New options are added regularily to the web version, after a testing phase.
