Mathematica , in its Combinatorica Package, has a function GraphCenter[] that computes the center of a graph (the set of vertices with minimum eccentricity--exactly your definition). You can find a description in the documentation here.
Mathematica, in its Combinatorica Package, has a function GraphCenter[] that computes the center of a graph (the set of vertices with minimum eccentricity--exactly your definition). You can find a description in the documentation here.