Create Adjacency Matrix

We can now convert the edge list into an adjacency matrix.

An adjacency matrix records whether a relationship exists between each pair of nodes.

Add the following to your R script and run it:

# Create adjacency matrix
adj_matrix <- matrix(0, nrow = length(nodes), ncol = length(nodes),
                     dimnames = list(nodes, nodes))
# Fill matrix with 1s for directed edges
for (i in 1:nrow(edge_list)) {
  from <- edge_list$df_IDs[i]
  to <- edge_list$targets[i]
  adj_matrix[from, to] <- 1
}

The matrix now records the presence (1) or absence (0) of relationships between nodes.

Direction

In this matrix, relationships are recorded as directed (from one node to another). In later steps, we will treat the network as undirected for analysis.

From this matrix, we can now calculate network measures such as degree, betweenness, and closeness.