Diameter of a graph
The diameter of a graph is the length of the longest geodesic.
diameter(graph, directed = TRUE, unconnected = TRUE, weights = NULL)
- The graph to analyze.
- Logical, whether directed or undirected paths are to be considered. This is ignored for undirected graphs.
- Logical, what to do if the graph is unconnected. If FALSE, the function will return a number that is one larger the largest possible diameter, which is always the number of vertices. If TRUE, the diameters of the connected components will be calculated an
- Optional positive weight vector for calculating weighted
distances. If the graph has a
weightedge attribute, then this is used by default.
The diameter is calculated by using a breadth-first search like method.
get_diameter returns a path with the actual diameter. If there are
many shortest paths of the length of the diameter, then it returns the first
farthest_vertices returns two vertex ids, the vertices which are
connected by the diameter path.
- A numeric constant for
diameter, a numeric vector for
farthest_verticesreturns a list with two entries:
verticesThe two vertices that are the farthest.
g <- make_ring(10) g2 <- delete_edges(g, c(1,2,1,10)) diameter(g2, unconnected=TRUE) diameter(g2, unconnected=FALSE) ## Weighted diameter set.seed(1) g <- make_ring(10) E(g)$weight <- sample(seq_len(ecount(g))) diameter(g) get_diameter(g) diameter(g, weights=NA) get_diameter(g, weights=NA)