How to compute the average weight of an undirected graph?

Question

Given a weighted, undirected graph $G = (V,E)$, how can I compute the average weight of edges?
It seems an easy problem (divide the total weight to the number of edges!) but I couldn't manage to find the sum of the edge weights since each edge can be counted several times while iterating through the vertices.

Answer 1

When you iterate over the vertices you will count every edge $e=\{v,w\}$ exactly twice (once when you visit $v$ and once when you visit $w$).

Thus you can sum up all weights of incident edges for every vertex and divide the result by $2\cdot m$ (where m is the amount of edges) to get the average weight.