Centrality measures of networks

So we have identified almost 30,000 relations between our 6,500 packages. Is it a sparse or dense network? In other words, how many connections do we have out of all possible package dependencies? What if all the packages depend on all other packages? We do not really need any feature-rich package to calculate that:

> nrow(edges) / (nrow(pkgs) * (nrow(pkgs) - 1))
[1] 0.0006288816

This is a rather low percentage, which makes the life of R sysadmins rather easy compared to maintaining a dense network of R software. But who are the central players in this game? Which are the top-most dependent R packages?

We can also compute a rather trivial metric to answer this question without any serious SNA knowledge, as this can be defined as "Which R package is mentioned the most times in the dep column of the edges dataset"? Or, in plain English: "Which package has the most reverse dependencies?"

> head(sort(table(edges$dep), decreasing = TRUE...