
7.4 Sequential Algorithms 161
• Miscellaneous algorithms, which do not fit the previous categories, for example, competitive
learning algorithms, valley-seeking algorithms, density-based algorithms, and subspace-clusteri ng
algorithms [Theo 09, Chapter 15].
Algorithms that return a hierarchy of clusterings include
• Agglomerative algorithms, which generate a sequence of clusterings of a decreasing number of
clusters, m. At each step, the pair of “closest” clusters in the current clustering is identified and
merged into one (while the remaining clusters are unaltered) in order to giveriseto the next clustering.
• Divisive al gorithms, which, in contrast ...