The spectral (or eigen) gap of a graph is the absolute difference between the biggest and second biggest eigenvalue of the adjacency matrix. To compare spectral gaps across networks, the fraction can be used.

spectral_gap(g, method = "frac")

## Arguments

g igraph object A string, either "frac" or "abs"

Numeric value

## Details

The spectral gap is bounded between 0 and 1 if method="frac". The closer the value to one, the bigger the gap.

## Examples

#The fractional spectral gap of a threshold graph is usually close to 1
g <- threshold_graph(50,0.3)
spectral_gap(g,method = "frac")#> [1] 0.8238