Graphscii

An application that prints ASCII representations of graphs! Implemented with Topology-Shape-Metrics [1]. Huge thanks to https://github.com/uknfire/tsmpy for their Doubly Connected Edge List and Compaction implementations. You can find some examples of graphscii's outputs here. You can also find a live demo of Graphscii here.

Features

• Support for nonplanar graphs.
• Support for disconnected graphs.
• Support for graphs with maximum degree > 4.
• Support for vertex labels.
• Support for directed graphs and multigraphs.
• Support for edge labels.
• Support for alternate character choices.

Usage

First, clone the repository, set up a virtual environment, and install the requirements. That might look something like this:

$ git clone https://github.com/raybbian/graphscii && cd graphscii
$ python3 -m venv venv
$ source venv/bin/activate
$ pip install -r requirements.txt

Then, you can print your graphs like this:

>>> import networkx as nx
>>> from graphscii import to_ascii
>>> graph = nx.complete_graph(5)
>>> print(to_ascii(graph, with_labels=True))

          ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
          ┃                                       ┃
          ┃                                       ┃
          ┃      ┏━━━━━┓                          ┃
          ┃      ┃     ┃                          ┃
          ┃ ┏━━━━┫  2  ┣━━━━━━━━━━━━━━━━┓         ┃
          ┃ ┃    ┃     ┣━━━━━━┓         ┃         ┃
          ┃ ┃    ┗━━┳━━┛      ┃         ┃         ┃
       ┏━━┻━┻┓   ┏━━┻━━┓   ┏━━┻━━┓      ┃         ┃
       ┃     ┃   ┃     ┃   ┃     ┃      ┃         ┃
       ┃  0  ┣━━━┫  3  ┣━━━┫  1  ┣━━━━━━╋━━━━━━━━━┛
       ┃     ┃   ┃     ┃   ┃     ┃      ┃
       ┗━━┳━━┛   ┗━━┳━━┛   ┗━━┳━━┛      ┃
          ┃         ┃      ┏━━┻━━┓      ┃
          ┃         ┗━━━━━━┫     ┃      ┃
          ┗━━━━━━━━━━━━━━━━┫  4  ┣━━━━━━┛
                           ┃     ┃
                           ┗━━━━━┛

Or maybe even write your graph to a file:

import networkx as nx
from graphscii import to_ascii

graph = nx.complete_bipartite_graph(3,3)
with open("output.txt", "w") as f:
    f.write(to_ascii(graph))

Contributing

If you find a bug in the code, and you can reproduce it for a certain graph, please feel free to open up an issue or a pull request. Your help towards fixing my terrible code is greatly appreciated.

Areas for Improvement

• Clean code up, merge the management of 3 data structures at once into one.
• Better comments and better code structure.
• Improved edge insertion (should yield much better drawings, see [4]).
• Successive shortest path algorithm, modified for negative cycles of length 2 (potentially could speed up process on large graphs, compared to MILP solution, see [2]).

Citations

[1] R. Tamassia. "On Embedding a Graph in the Grid with the Minimum Number of Bends," in SIAM Journal on Computing, vol. 16, no. 3, pp. 421-444, 1987.

[2] M. Foßmeier, "Drawing high degree graphs with low bend numbers," in Graph Drawing, 1996, pp. 254–266.

[3] M. Eiglsperger, M. Kaufmann, "Fast Compaction for Orthogonal Drawings with Vertices of Prescribed Size," in Lecture Notes in Computer Science, 2002.

[4] Carsten Gutwenger, P. Mutzel, and R. Weiskircher, “Inserting an Edge into a Planar Graph,” Algorithmica, vol. 41, no. 4, pp. 289–308, Jan. 2005.