[igraph] centrality eigenvector vs hub/auth - ARPACK LM vs LA

[Matthew Galati]

I was looking at the ARPACK implementation of centrality.

I noticed, that for eigenvector centrality, you are using LA, while for hub/authority/page-rank scores, you are using LM. I believe the power method will give LM - which is the alternate way to calculate these metrics (under some conditions).

What is the reason behind using LA for eigenvector centrality (instead of using LM)? The literature seems to be a little ambiguous - using terms like "largest" but not clarifying if that is algebraic or magnitude (in the presence of negative eigenvalues).

Thanks in advance,

Matt