| graph.difference {igraph} | R Documentation |
The difference of two graphs are created.
graph.difference(big, small, byname = "auto")
big |
The left hand side argument of the minus operator. A directed or undirected graph. |
small |
The right hand side argument of the minus operator. A directed ot undirected graph. |
byname |
A logical scalar, or the character scalar
|
graph.difference creates the difference of two graphs. Only
edges present in the first graph but not in the second will be be
included in the new graph. The corresponding operator is %m%.
If the byname argument is TRUE (or auto and the
graphs are all named), then the operation is performed based on
symbolic vertex names. Otherwise numeric vertex ids are used.
graph.difference keeps all attributes
(graph, vertex and edge) of the first graph.
Note that big and small must both be directed or both be
undirected, otherwise an error message is given.
A new graph object.
Gabor Csardi csardi.gabor@gmail.com
## Create a wheel graph
wheel <- graph.union(graph.ring(10),
graph.star(11, center=11, mode="undirected"))
V(wheel)$name <- letters[seq_len(vcount(wheel))]
## Subtract a star graph from it
sstar <- graph.star(6, center=6, mode="undirected")
V(sstar)$name <- letters[c(1,3,5,7,9,11)]
G <- wheel %m% sstar
str(G)
plot(G, layout=layout.auto(wheel))