# File lib/ai4r/clusterers/weighted_average_linkage.rb, line 51 def linkage_distance(cx, ci, cj) ni = @index_clusters[ci].length nj = @index_clusters[cj].length (1.0 * ni * read_distance_matrix(cx, ci)+ nj * read_distance_matrix(cx, cj))/(ni+nj) end