This script creates random planar graphs, suitable as input to graphviz neato.

The simplest invocation is:

python GenerateGraph.py outputgraph.gv

which you could then render with:

neato -Tpng outputgraph.gv > outputgraph.png

Note that sometimes neato decides to pick a nonplanar embedding. Try giving neato the -n1 argument to use the node coordinates specified by this script, which are always planar but might not look as pretty. If you do, you might also want to specify -Nshape=circle to tell neato to use circular nodes. The default coordinates assume nodes are roughly circular.

You can read the help text for details on options:

python GenerateGraph.py --help

The most common options are:

• --width SIZE: Width of the field on which to place points. neato might choose a different width for the output image.
• --height SIZE: Height of the field on which to place points. As above, neato might choose a different size.
• --nodes NUM: Number of nodes to place.
• --edges NUM: Number of edges to use for connections. Double edges aren't counted.
• --radius SIZE: Nodes will not be placed within this distance of each other. Default 40.
• --double CHANCE: Probability of an edge being doubled. Ranges from 0.00 to 1.00. Default 0.10.

Copyright (C) 2014 GreyKnight

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies of the Software, its documentation and marketing & publicity materials, and acknowledgment shall be given in the documentation, materials and software packages that this Software was used.

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