Welcome to the
Rocchini's Graphs
claudiorockini.name

About named graphs: for Higman-Sims Graph thanks to Paul R. Hafner, but I'm not satisfied with the image of the composite results. For Dipole Graph I had to think long time. The Hoffman Singleton Graph would need to be combed. The stupid image of Hypergraph is very famous. Why? The Hall-janko Graph is drawn with ugly colors, but I do not know how to improve it. And about my picture of Foster Graph? Silence is better than unmeaning words...

About coloring: most pictures are brute force search. Complete coloring of Clebsh Graph (each color appear exactly twice!) and Fractional Coloring are masterpieces. Counterexamples and enumeative examples are difficult to show (i.e. Strong Coloring, Friend Theorem). The Harmonious Coloring sample graph seems trivial, but try to improve it (if you can)!

Local mclaughlin graph: one of the worst pictures I've drawn. complete source code here.

Chang graphs. In the first try of this images I have used nauty for finding symmetric draws. But the Chang's graphs are very asimmetric and a good symmetric dwawing does not exist. In the second try I show the graph's construction from T8.

Gallery

Centrality - SVG File - Dirty C++ source code
Vertex Critical Graph example, Many thanks to Gordon Royles for the graph.
Polygon-Circle Graph - SVG File
Random Geometric Graph - SVG File
Rectilinear Minimum Spanning Tree - SVG FILE
Urquhart Graph - SVG File
Exact Coloring - SVG File
Generalized Quadrangle (2,4) - SVG File
J5 Circular Color - SVG File
M22 Graph SVG File
Schlafli Graph - Schlafli_graph.svg - schlafli_graph.c++ source code
Graph Star Coloring - Graph_star_coloring.svg
Local MC Laughlin Graph - Local_mclaughlin_graph.svg - local_mclaughlin_graph.c++ source code
Chang's Graphs - Chang_graphs.svg
Acyclic Coloring - Acyclic_coloring.svg
Art Gallery Problem - Art_gallery_problem.svg
Cocoloring - Cocoloring.svg
Complete Coloring of Clebsch Graph - Complete_coloring_clebsch_graph.svg
Foster Graph - Foster_graph.svg
Graph Betweenness - Graph_betweenness.svg
Gq21 Strong Coloring - Strong_coloring_sample.svg
Graph Fractional Coloring - Graph_fractional_coloring.svg
Hall-Janko Graph - Hall_janko_graph.svg
Harmonious Coloring of a Tree - Harmonious_coloring_tree.svg
Higman-Sims Graph - Higman_Sims_Graph.svg - hygman_sysm source code
Higman-Sims Graph (split int Parts) - Higman_Sims_Graph_Parts.svg
Sample of Strong Coloring
Total Coloring of Foster Cage - Total_coloring_foster_cage.svg
Visibility Polygon - Visibility_polygon.svg
Complement Graph Sample
Friends Theorem
Hypergraph
Intersection Graph
Sample of Kautz Graph
Sample of Toroidal Graph
Exact Coloring of a complete grap
Hoffman-Singleton graph
The dipole graph
Edge coloring of Desargues graph
Some 7-simmetry embedding of Gewirtz graph - gewirtz_graph_embeddings.svg
Some 19-simmetry embedding of Perkel graph - perkel_graph_embeddings.svg
Some embeddings of Brouwer Haemers graph - Brouwer_Haemers_graph.svg - brouwer_haemers_graph.c++ source code

Final Notes

The Kautz Graph is completely handmade. It seems nice?

Errors and Corrections: Arthena found an error on Art Gallery Problem: great powers of observation! Nicinic found an error on Toroidal Graph.

Schlafli graph: the construction is easy: below the source code.

Brouwer Haemers graph: complete source code of construction and symmetric drawing using nauty. You can get an idea of what means "using nauty".

Many thanks to Nauty for simmetrycal graph embedding!

Todo: I have in my pocket (for many years) a picture of Null Graph, I do not have the courage to post it on wikicommons. This picture looks a lot like the Invisible Pink Unicorn

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