Plotting the SCCP

In this tutorial, we will be using the drawing capabilities from networkx to plot a simple debate’s space of coherent and complete positions (SCCP).

Let’s go ahead with a really simple debate:

from taupy import *
from sympy import symbols

# declare five sentence variables
p1, p2, p3, p4, p5 = symbols("p:5")

# create a simple debate with two arguments.
d = Debate(Argument(p1&p2&p3, p4), Argument(p5&~p2, ~p3))

taupy.basic.core.Base.sccp() returns a dictionary of list representation of a graph, which can be easily imported by networkx.

import networkx as nx

# create the graph with the sccp() method of the Debate object.
graph = nx.from_dict_of_lists(d.sccp())

# choose a layout (optional)
layout = nx.kamada_kawai_layout(graph)

# plot the graph. networkx uses matplotlib here.
nx.draw(graph, pos=layout, with_labels=True, node_color="#aaa")

In the resulting figure below, nodes have a label that shows the bit string representation of the position they resemble. In this bit string, propositions are ordered alphabetically (p1 will show in the first bit, p5 in the last), and they are either 0 if the position assigns False to this proposition, or 1 if the position accepts the proposition. Positions are connected by an edge if they differ in exactly one truth-value attribution (i.e., if their Hamming distance equals 1).