Figure 1

Number of structure–activity relationship (SAR) clusters. These numbers do not include clusters with only one compound (i.e., singletons). 3-D clusters that have multiple conformers of only one compound were also regarded as singletons and not included in the statistics. N _total indicates the total number of clusters for a given bioactivity similarity context. Numbers in parentheses on the pie charts indicate the percentage of five cluster types (based on structural similarity measures used in clustering) with respect to N _total for the corresponding bioactivity similarity context. For all three bioactivity similarity contexts, there are more 3-D clusters than 2-D clusters.