neighbor_states, an Octave code which records information about pairs of US states which are neighbors.
The computer code and data files made available on this web page are distributed under the MIT license
neighbor_states is available in a MATLAB version and an Octave version and a Python version.
neighbor_risk, an Octave code which records information about neighboring pairs of territories in the game of RISK.
usa_matrix, an Octave code which defines the adjacency matrix for US states, using a variety of matrix formats.