**graphviz_test**,
a Python code which
calls graphiviz(), which
displays representations of graphs.

The graphviz() and pydotplus() packages must be installed in order for these programs to work.

The computer code and data files made available on this web page are distributed under the GNU LGPL license.

- graphviz_test.py, calls all the tests;
- graphviz_test.sh, runs all the tests;
- graphviz_test.txt, the output file;

- timestamp.py, prints the YMDHMS date as a timestamp.

**alphabet_binary_tree** describes a binary tree that could be used
to alphabetize letters.

- alphabet_binary_tree.py, sets up the graph and makes a plot.
- alphabet_binary_tree.dot, a dot version of the plot.
- alphabet_binary_tree.dot.png, the plot.

**network_graph** describes a graph as a set of edges, defined
by pairs of nodes.

- network_graph.py, sets up the graph and makes a plot.
- network_graph.dot, a dot version of the plot.
- network_graph.dot.png, the plot.

**web_digraph** displays a set of directed connections as a digraph.

- web_digraph.py, sets up the graph and makes a plot.
- web_digraph.dot, a dot version of the plot.
- web_digraph.dot.png, the plot.