igraph中具有孤立节点的pagerank

Question

I wonder how the page_rank() in R's igraph package workes when there are isolated nodes. For example,

g <- graph(edges=c(1,2), n = 3, directed = F)
page_rank(g, algo = "prpack")

I got (with default damping factor being 0.85.)

$vector
[1] 0.46511628 0.46511628 0.06976744

Why is this result? I thought node 3 should be 0.15 / 3 .

Answer 1

I think i figured out the reason. Using the standard page rank algorithm (see wiki ), I get (1/3, 1/3, 1/20) . Normalize it to a distribution, I get (0.46511628 0.46511628 0.06976744) .