optrees (version 1.0)

checkArbor: Checks if there is at least one arborescence in the graph

Description

Given a directed graph, checkArbor searchs for an arborescence from the list of arcs. An arborescence is a directed graph with a source node and such that there is a unique path from the source to any other node.

Usage

checkArbor(nodes, arcs, source.node = 1)

Arguments

nodes

vector containing the nodes of the graph, identified by a number that goes from $1$ to the order of the graph.

arcs

matrix with the list of arcs of the graph. Each row represents one arc. The first two columns contain the two endpoints of each arc and the third column contains their weights.

source.node

source node of the graph. Its default value is $1$.

Value

If checkArbor found an arborescence it returns TRUE, otherwise it returns FALSE. If there is an arborescence the function also returns the list of arcs of the arborescence.

See Also

This function is an auxiliar function used in msArborEdmonds and getMinimumArborescence.