# eccentricity#

eccentricity(G, v=None, sp=None, weight=None)[source]#

Returns the eccentricity of nodes in G.

The eccentricity of a node v is the maximum distance from v to all other nodes in G.

Parameters:
GNetworkX graph

A graph

vnode, optional

Return value of specified node

spdict of dicts, optional

All pairs shortest path lengths as a dictionary of dictionaries

weightstring, function, or None (default=None)

If this is a string, then edge weights will be accessed via the edge attribute with this key (that is, the weight of the edge joining `u` to `v` will be `G.edges[u, v][weight]`). If no such edge attribute exists, the weight of the edge is assumed to be one.

If this is a function, the weight of an edge is the value returned by the function. The function must accept exactly three positional arguments: the two endpoints of an edge and the dictionary of edge attributes for that edge. The function must return a number.

If this is None, every edge has weight/distance/cost 1.

Weights stored as floating point values can lead to small round-off errors in distances. Use integer weights to avoid this.

Weights should be positive, since they are distances.

Returns:
eccdictionary

A dictionary of eccentricity values keyed by node.

Examples

```>>> G = nx.Graph([(1, 2), (1, 3), (1, 4), (3, 4), (3, 5), (4, 5)])
>>> dict(nx.eccentricity(G))
{1: 2, 2: 3, 3: 2, 4: 2, 5: 3}
```
```>>> dict(nx.eccentricity(G, v=[1, 5]))  # This returns the eccentricity of node 1 & 5
{1: 2, 5: 3}
```