Directed networks

Network Analysis in R

James Curley

Associate Professor, University of Texas at Austin

Directionality

Undirected:

    IGRAPH UN-- 7 7 -- 
    + attr: name (v/c)
    + edges (vertex names):
    [1] A--B A--C A--D A--E A--F E--F F--G

Directed:

    IGRAPH DN-- 7 7 -- 
    + attr: name (v/c)
    + edges (vertex names):
    [1] A->E B->A C->A D->A F->A F->E F->G

is.directed(g)

[1] TRUE

is.weighted(g)

[1] FALSE

Is there an edge between A & E?

g['A','E']

[1] 1

Show all edges to or from A:

incident(g,'A', mode=c("all"))

+ 5/7 edges (vertex names):
[1] A->E B->A C->A D->A F->A

Find the starting vertex of all edges:

head_of(g, E(g))

+ 7/7 vertices, named:
[1] A B C D F F F

Network Analysis in R