In weighted graphs, a real number is assigned to each (directed or undirected) edge.
- The input graph.
In igraph edge weights are represented via an edge attribute, called
is_weighted function only checks that such an
attribute exists. (It does not even checks that it is a numeric edge
Edge weights are used for different purposes by the different functions. E.g. shortest path functions use it as the cost of the path; community finding methods use it as the strength of the relationship between two vertices, etc. Check the manual pages of the functions working with weighted graphs for details.
- A logical scalar.
g <- make_ring(10) shortest_paths(g, 8, 2) E(g)$weight <- seq_len(ecount(g)) shortest_paths(g, 8, 2)