[igraph] shortest paths in a undirected weighted graph

[federico vaglio]

Hi to all,
is there a way to get all shortest paths, not just lengths, between two vertices in a undirected weighted graph?

get.shortest.paths function has "weights" argument but gives only one shortest path, even if more than one shortest path exist between given vertices.

get.all.shortest.paths function returns all possible shortest paths but ignores edge weights, even if passed graph has a weight attribute.

How to get the best of both ?


Thank you in advance

Example code.

require(igraph)

# create a graph with 5 vertices
g <- graph.empty(5, dir=FALSE)

# add edges
g <- add.edges(g, c(0, 1, 0, 2, 0, 3, 1, 4, 2, 4, 3, 4))

# edge weigths
E(g)$weight <- c(1, 1, 2, 1, 1, 1)

# use weights but return only one path
get.shortest.paths(g, from=0, to=4)

#
# my result
#[[1]]
#[1] 0 2 4


# return all shortes paths but ignore weights
get.all.shortest.paths(g, from=0, to=4)

#
# my result
#[[1]]
#[1] 0 3 4
#
#[[2]]
#[1] 0 2 4
#
#[[3]]
#[1] 0 1 4