Builds the list of arcs of a graph from its cost matrix
Description
The Cmat2ArcList
function builds the list of arcs of
a graph from a cost matrix that contains the weights of all
the arcs.
Usage
1  Cmat2ArcList(nodes, Cmat, directed = TRUE)

Arguments
nodes 
vector containing the nodes of the graph, identified by a number that goes from 1 to the order of the graph. 
Cmat 
n\times n matrix that contains the
weights or costs of the arcs. Row i and column
j represents the endpoints of an arc, and the value
of the index ij is its weight or cost. If this
value is 
directed 
logical value indicating whether the
graph is directed ( 
Value
Cmat2ArcList
returns a 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.