isle {streamDAG}

Detects and defines islands in a streamDAG

Description

The function was written primarilly to recognize DAG islands to allow correct implementation of the function stream.order and is still early in its development.

Usage

isle(G)

Arguments

G

Graph object of class igraph. See graph_from_literal.

Details

The function currently allows detection of simple island structures (those that don't contain sub-islands). One of the output objects from the function is a new graph object with island nodes into a single node(s).

Value

Output consists of the following:

test

Logical indicating whether or not G contains islands.

island

List of islands with their nodal components

input.id

Neighboring node(s) directly upstream from island(s).

output.id

Neighboring node(s) directly downstream from island(s).

new.graph

New graph object created from G in which nodes constituing islands a combined into a single node

island.names

Names of island nodes created in new output graph (that combines nodes constituing islands into a single node). Follows the naming system "i-1", "i-2", etc.

splits

The number of islands detected.

Author(s)

Ken Aho

See Also

stream.order, delete.vertices, codeadd.vertices, codeadd.edges

Examples

G <- graph_from_literal(a --+ c --+ e, b --+ d --+ e --+ f --+ p, g --+ i --+ j --+ m, 
i --+ k --+ m, m --+ n --+ o --+ p, h --+ l --+ n, p --+ q --+ r)
plot(G)
isle(G)