The eccentricity 
of a graph vertex 
in a connected graph 
is the maximum graph
distance between 
and any other vertex 
of 
.
For a disconnected graph, all vertices are
defined to have infinite eccentricity (West 2000, p. 71).
The maximum eccentricity is the graph diameter. The minimum graph eccentricity is called the graph radius.
Eccentricities are implemented as Eccentricity[g] in the Wolfram Language package Combinatorica`
. A nonstandard version of graph eccentricity for a given vertex 
is implemented as VertexEccentricity[g,
v], which gives the eccentricity for the connected
component in which 
is contained. Precomputed standard eccentricities (assuming
infinite values for disconnected graphs) for a number of named graphs can be obtained
using GraphData[graph,
"Eccentricities"].
