Tab. 2. Intermodular similarity as determined by cosine of angle between module substructure importance vectors.

Substructure importance vectors are determined via analog to TFIDF, where a module’s importance for a given substructure is given by its frequency within the module multiplied by the inverse of its frequency in all substances. Green cells show the greatest similarity for the module in each row. These similarities fit well with visual inspection of Figure 4.

Module	0	1	2	3	4	5	6	7	8
0	1.00	0.26	0.02	0.24	0.18	0.19	0.26	0.36	0.18
1	0.26	1.00	0.06	0.09	0.23	0.08	0.43	0.16	0.15
2	0.02	0.06	1.00	0.06	0.10	0.05	0.10	0.04	0.02
3	0.24	0.09	0.06	1.00	0.04	0.53	0.11	0.32	0.05
4	0.18	0.23	0.10	0.04	1.00	0.02	0.43	0.04	0.22
5	0.19	0.08	0.05	0.53	0.02	1.00	0.13	0.40	0.04
6	0.26	0.43	0.10	0.11	0.43	0.13	1.00	0.20	0.30
7	0.36	0.16	0.04	0.32	0.04	0.40	0.20	1.00	0.09
8	0.18	0.15	0.02	0.05	0.22	0.04	0.30	0.09	1.00