is.weighted {igraph}R Documentation

Weighted graphs

Description

In weighted graphs, a real number is assigned to each (directed or undirected) edge.

Usage

is.weighted(graph)

Arguments

graph

The input graph.

Details

In igraph edge weights are represented via an edge attribute, called ‘weight’. The is.weighted function only checks that such an attribute exists. (It does not even checks that it is a numeric edge attribute.)

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.

Value

A logical scalar.

Author(s)

Gabor Csardi csardi.gabor@gmail.com

Examples

g <- graph.ring(10)
get.shortest.paths(g, 8, 2)
E(g)$weight <- seq_len(ecount(g))
get.shortest.paths(g, 8, 2)

[Package igraph version 0.7.0 Index]