Adjacency Matrix

• NxN matrix where (m,n) is set if there is an edge between the nodes m and n or 0 otherwise
• For undirected graphs, this is always symmetric
• For large sparse ones, it can be a list of connections to save memory
• The $n^{th}$ node has an associated node embedding x(n) of length D. These embeddings are concatenated and stored in the D×N node data matrix X. Similarly, the $e^{th}$ edge has an associated edge embedding e(e) of length DE . These edge embeddings are collected into the $D_E\times E$ matrix E.

Properties of Adjacency matrix