Returns an adjacency list from an edge list

Usage

get_adj_list(el, n_nodes)

Arguments

el: An edge list as a data.frame with columns head and tail
n_nodes: The size number of node in the network

Value

An adjacency list for the network

Details

The adjacency list is a list of length n_nodes. The entry for each node is a integer vector containing the index of all the nodes connected to it. This layout makes it directly subsetable in O(1) at the expanse of memory usage. To get all connections to the nodes 10 and 15 : unlist(adj_list[c(10, 15)]