Graphtacular

early codeC# · 2019

A C# console app I wrote in 2019, before AI tools were around. A graph grows itself from one seed vertex by following a shared list of instructions, like a genome.

History: kept as the 2019 original. Its strand idea now lives on in split_load_sim, which swaps the string-matched instructions for typed, checked ones and uses the graphs to test the Genius Study's assumptions.

How it grows

Vertex and kernel. Each vertex holds a kernel. The kernel can act on its own vertex and on the graph the vertex is in.
Strand. A strand is a numbered list of instructions that every vertex shares. One step looks like {"KbranchUndirected",1,1}: add one child on an undirected edge of weight 1.
Growth. The seed vertex runs the first step. Each vertex it makes runs the next step, and so on down the strand, so the whole graph grows from one seed.
Cap. Growth stops at 3,828 vertices.

// StrandLib.cs: the Flower strand
 1  {"KcompleteCluster", 8, 1}
 2  {"KbranchUndirected", 1, 1}
..  // 3 to 6: the same branch
 7  {"KcompleteCluster", 8, 1}
..  // the pattern twice more
19  {null}

KcompleteCluster with 8 adds eight children that are all joined to each other. KbranchUndirected with 1 adds one child on an edge. null ends the strand.

Renders

Graphs are exported as GEXF files and rendered in Gephi.

A Gephi render on white: a dense central cluster with eight arms, each ending in smaller clusters of pale green vertices — Fibonacci

A Gephi render on white: a small central cluster with four long branches, each ending in a cluster that branches again — Flower fractal

The Graph class

It stores the graph as an adjacency matrix. Besides growing graphs, the Graph class measures them:

degree (in, out, and mutual edges)
neighbors, and neighbors within k steps
islands (disconnected pieces)
clustering coefficient

Green-on-black console output from 2019: a 9-by-9 adjacency matrix with a GUID and kernel for each vertex, then each vertex's neighbor list — Console output from 2019: the adjacency matrix and neighbor lists for a nine-vertex graph.

Build

C# console app
.NET Core 2.2 (still builds on .NET 8)
89 xUnit tests (all still pass)
export: GEXF

Links

Repo: neuresthetics/graphtacular Successor: split_load_sim

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