tsort {RBGL}R Documentation

topological sort of vertices of a digraph

Description

returns vector of zero-based indices of vertices of a DAG in topological sort order

Usage

tsort(x) # now x assumed to be Bioconductor graph graphNEL

Arguments

x instance of class graphNEL from Bioconductor graph class

Details

calls to the topological_sort algorithm of BGL. will check in BGL whether the input is a DAG and return a vector of zeroes (of length length(nodes(x))) if it is not. Thus this function can be used to check for cycles in a digraph.

Value

a numerical vector enumerating vertices in the topological sort sequence, 0-based

Author(s)

VJ Carey <stvjc@channing.harvard.edu>

Examples

 data(FileDep)
 tsind <- tsort(FileDep)
 tsind
 FD2 <- FileDep
 # now introduce a cycle
 FD2 <- addEdge("bar_o", "dax_h", FD2, 1)
 tsort(FD2)
 

[Package RBGL version 1.10.0 Index]