I'm a little confused by the concept of a "negative" edge weight. All of the examples I have seen represent negative edge weights as negative numbers. Is it possible for an edge weight to carry a negative weight, and be represented as a positive number?
As an example, suppose we had a graph of a network where the edges represent the time elapsed for data to travel between server A and server B. Suppose that we had a weight on each edge representing the lag time between certain servers (so perhaps the time for the data to travel between A and B has a lag of time t, which means the total time can be shown as the time to get to B from A, plus the lag). Is "lag" a negative edge weight in this case, even though it is a positive number?