graph_topo_sort: Topological sort of vertices in directed acyclic graph
Description
A topological ordering of a directed graph is a linear
ordering of its vertices such that, for every edge (u->v), u
comes before v in the ordering. A topological ordering is
possible if and only if the graph has no directed cycles, that
is, if it is a directed acyclic graph (DAG). Any DAG has at
least one topological ordering. Can hence be used for checking
if a graph is a DAG.
Usage
topo_sort(object, index = FALSE)
topo_sortMAT(amat, index = FALSE)
topoSort(object, index = FALSE)
topoSortMAT(amat, index = FALSE)
Value
If FALSE, an ordering is returned if it exists and
character(0) otherwise. If TRUE, the index of the
variables in an adjacency matrix is returned and -1
otherwise.
Arguments
object
An graph represented either as a graphNEL
object, an igraph, a (dense) matrix, a (sparse)
dgCMatrix.
index
If FALSE, an ordering is returned if it exists and
character(0) otherwise. If TRUE, the index of the
variables in an adjacency matrix is returned and -1
otherwise.
amat
Adjacency matrix.
Synonymous functions
The functions topo_sort / topoSort are synonymous with topo_sortMAT /
topoSortMAT. One of the groups may be deprecated in the future.