# Ticket #14904: trac_14904_folkman_graph_fc.patch

File trac_14904_folkman_graph_fc.patch, 2.5 KB (added by chapoton, 9 years ago)
• ## sage/graphs/generators/smallgraphs.py

```# HG changeset patch
# User Frederic Chapoton <chapoton at math.univ-lyon1.fr>
# Date 1374064940 -7200
# Node ID 2af146179a7d884e4ea847bdf2b81b08b3fbff3d
# Parent  fc122a1cc540947c3a6dbfe0a22db3f7d5175812
trac 14904 the Folkman graph

diff --git a/sage/graphs/generators/smallgraphs.py b/sage/graphs/generators/smallgraphs.py```
 a def FlowerSnark(): 12:[13,19],13:[14],15:[19],16:[15,17],18:[17,19]}, \ pos=pos_dict, name="Flower Snark") def FolkmanGraph(): """ Returns the Folkman graph. See the :wikipedia:`Wikipedia page on the Folkman Graph `. EXAMPLE:: sage: g = graphs.FolkmanGraph() sage: g.order() 20 sage: g.size() 40 sage: g.diameter() 4 sage: g.girth() 4 sage: g.charpoly().factor() (x - 4) * (x + 4) * x^10 * (x^2 - 6)^4 sage: g.chromatic_number() 2 sage: g.is_eulerian() True sage: g.is_hamiltonian() True sage: g.is_vertex_transitive() False sage: g.is_bipartite() True """ from sage.graphs.generators.families import LCFGraph g= LCFGraph(20, [5, -7, -7, 5], 5) g.name("Folkman Graph") return g def FosterGraph(): """ Returns the Foster graph.
• ## sage/graphs/graph_generators.py

`diff --git a/sage/graphs/graph_generators.py b/sage/graphs/graph_generators.py`
 a def __append_to_doc(methods): "EllinghamHorton78Graph", "ErreraGraph", "FlowerSnark", "FolkmanGraph", "FosterGraph", "FranklinGraph", "FruchtGraph", class GraphGenerators(): EllinghamHorton78Graph   = staticmethod(sage.graphs.generators.smallgraphs.EllinghamHorton78Graph) ErreraGraph              = staticmethod(sage.graphs.generators.smallgraphs.ErreraGraph) FlowerSnark              = staticmethod(sage.graphs.generators.smallgraphs.FlowerSnark) FolkmanGraph             = staticmethod(sage.graphs.generators.smallgraphs.FolkmanGraph) FosterGraph              = staticmethod(sage.graphs.generators.smallgraphs.FosterGraph) FranklinGraph            = staticmethod(sage.graphs.generators.smallgraphs.FranklinGraph) FruchtGraph              = staticmethod(sage.graphs.generators.smallgraphs.FruchtGraph)