lib/ai4r/clusterers/ward_linkage.rb in ai4r-1.12 vs lib/ai4r/clusterers/ward_linkage.rb in ai4r-1.13

- old
+ new

@@ -14,24 +14,24 @@ module Clusterers # Implementation of an Agglomerative Hierarchical clusterer with # Ward's method linkage algorithm, aka the minimum variance method (Everitt # et al., 2001 ; Jain and Dubes, 1988 ; Ward, 1963 ). - # Hierarchical clusteres create one cluster per element, and then + # Hierarchical clusterer create one cluster per element, and then # progressively merge clusters, until the required number of clusters # is reached. - # The objective of this method is to minime the variance. + # The objective of this method is to minimize the variance. # # D(cx, (ci U cj)) = (ni/(ni+nj+nx))*D(cx, ci) + # (nj/(ni+nj+nx))*D(cx, cj) - # (nx/(ni+nj)^2)*D(ci, cj) class WardLinkage < SingleLinkage parameters_info :distance_function => "Custom implementation of distance function. " + "It must be a closure receiving two data items and return the " + - "distance bewteen them. By default, this algorithm uses " + - "ecuclidean distance of numeric attributes to the power of 2." + "distance between them. By default, this algorithm uses " + + "euclidean distance of numeric attributes to the power of 2." # Build a new clusterer, using data examples found in data_set. # Items will be clustered in "number_of_clusters" different # clusters. def build(data_set, number_of_clusters)