1 <?xml version="1.0" encoding="UTF-8"?>
2 <!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
4 <maintainer type="project">
5 <email>sci-mathematics@gentoo.org</email>
6 <name>Gentoo Mathematics Project</name>
8 <longdescription lang="en">
9 Gfan is a software package for computing Gröbner fans and tropical
10 varieties. These are polyhedral fans associated to polynomial
11 ideals. The maximal cones of a Gröbner fan are in bijection with the
12 marked reduced Gröbner bases of its defining ideal. The software
13 computes all marked reduced Gröbner bases of an ideal. Their union
14 is a universal Gröbner basis. The tropical variety of a polynomial
15 ideal is a certain subcomplex of the Gröbner fan. Gfan contains
16 algorithms for computing this complex for general ideals and
17 specialized algorithms for tropical curves, tropical hypersurfaces
18 and tropical varieties of prime ideals. In addition to the above
19 core functions the package contains many tools which are useful in
20 the study of Gröbner bases, initial ideals and tropical
21 geometry. The full list of commands can be found in Appendix B of
22 the manual. For ordinary Gröbner basis computations Gfan is not
23 competitive in speed compared to programs such as CoCoA, Singular