One-hot encoding represents each category with a vector containing one active entry and inactive entries elsewhere. In graph encoders, it records which receiving node each directed edge targets. section 6.4.1
A practical edge-to-node aggregation pipeline is:
- Create one category position for every node and mark each edge's receiving-node position. section 6.4.1
- Transpose the encoding so its shape becomes number of nodes by number of edges. section 6.4.1
- Multiply the fixed matrix by edge embeddings to aggregate incoming messages into node embeddings, then normalize by possible nodes. section 6.4.1
Three-node fully connected graph
Six directed edges connect every node to the other two. The one-hot incoming-edge matrix marks each edge's destination, allowing edge embeddings to become three node embeddings.





