Spectral Clustering is a technique to cluster data which finds application in community detection applications. It is equivalent to finding a min-cut of a graph where edge (or their weights) represents closeness which is subjective to data and context.
Dolphins Community Detetction, Two Circles Problem (Spectral clustering from scratch)
data: data.zip
Barca - Real Madrid clustering problem (everything from scratch - eigenvalues,eigenvecs, spectral clusetring)
data: lclassico.gml