Add Edges to an Adjacency List

add_edge(adj, v1, v2, ids = NULL, zero = TRUE)

Arguments

adj: list of adjacent precincts
v1: vector of vertex identifiers for the first vertex. Can be an integer index or a value to look up in ids, if that argument is provided. If more than one identifier is present, connects each to corresponding entry in v2.
v2: vector of vertex identifiers for the second vertex. Can be an integer index or a value to look up in ids, if that argument is provided. If more than one identifier is present, connects each to corresponding entry in v2.
ids: A vector of identifiers which is used to look up the row indices for the vertices. If provided, the entries in v1 and v2 must match exactly one entry in ids.
zero: boolean, TRUE if the list is zero indexed. False if one indexed.

Value

adjacency list.

Examples

data(towns)
adj <- adjacency(towns)

add_edge(adj, 2, 3)
#> [[1]]
#> [1] 3 4 6
#> 
#> [[2]]
#> [1] 4 2
#> 
#> [[3]]
#> [1] 3 5 1
#> 
#> [[4]]
#> [1] 0 4 2 6 5
#> 
#> [[5]]
#> [1] 0 1 3 5
#> 
#> [[6]]
#> [1] 3 4 2 6
#> 
#> [[7]]
#> [1] 0 3 5
#> 
add_edge(adj, "West Haverstraw", "Stony Point", towns$MUNI)
#> [[1]]
#> [1] 3 4 6
#> 
#> [[2]]
#> [1] 4
#> 
#> [[3]]
#> [1] 3 5
#> 
#> [[4]]
#> [1] 0 4 2 6 5 5
#> 
#> [[5]]
#> [1] 0 1 3 5
#> 
#> [[6]]
#> [1] 3 4 2 6 3
#> 
#> [[7]]
#> [1] 0 3 5
#>