Clusters functionally related biological terms from gene set
enrichment results. Terms are compared by the overlap of their gene
sets using Cohen's kappa, the Jaccard index, or the Dice coefficient,
and the resulting similarity matrix is grouped either by agglomerative
hierarchical clustering with single, complete, average, or Ward
linkage, or by the seed-and-merge procedure of the 'DAVID' functional
classification tool. The distance and clustering routines are written
in 'C++' for speed. The methods are described in Huang et al. (2007)