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

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

Thus the above example can be rendered as:

Also see

• Results about signed graphs can be found here.

Sources

• 1977: Gary Chartrand: Introductory Graph Theory ... (previous) ... (next): Chapter $1$: Mathematical Models: $\S 1.6$: Networks as Mathematical Models