topological.sort {igraph} | R Documentation |
A topological sorting of a directed acyclic graph is a linear ordering of its nodes where each node comes before all nodes to which it has edges.
topological.sort(graph, mode=c("out", "all", "in"))
graph |
The input graph, should be directed |
mode |
Specifies how to use the direction of the edges.
For “out ”, the sorting order ensures that each node comes
before all nodes to which it has edges, so nodes with no incoming
edges go first. For “in ”, it is quite the opposite: each
node comes before all nodes from which it receives edges. Nodes
with no outgoing edges go first. |
Every DAG has at least one topological sort, and may have many. This function returns a possible topological sort among them. If the graph is not acyclic (it has at least one cycle), a partial topological sort is returned and a warning is issued.
A numeric vector containing vertex ids in topologically sorted order.
Tamas Nepusz ntamas@rmki.kfki.hu and Gabor Csardi csardi@rmki.kfki.hu for the R interface
g <- barabasi.game(100) topological.sort(g)