Definition:Signed Graph

Definition
A signed graph is an undirected network whose functional values are $\pm 1$.

The edges of such a graph are known as positive edges and negative edges.

It is usual to indicate the functional values by means of just the $+$ or $-$ sign.

Example

 * SignedGraph.png

Alternative Representation
Another way to represent a signed graph is to use two different line styles: one to represent positive edges and one for the negative ones.

Thus the above example can be rendered as:


 * SignedGraphAlt.png