topo_sort: Topological sorting of vertices in a graph
Description
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.
Usage
topo_sort(graph, mode = c("out", "all", "in"))
Arguments
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,
Value
A numeric vector containing vertex ids in topologically sorted
order.
Details
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.