The initial set B of commercial compounds is divided into K clusters according to the pattern of the chemical structures. First, the chemical structure S is transformed into a descriptor vector ϕ(S) of length 3239 with the concatenation of RDKit fingerprint (length 2048), MACCS (Molecular ACCess System) keys (length 167), and Morgan fingerprint of radius 2 (length 1024). Then, generative topographic mapping (GTM) is applied , which is a well-established integrated method of dimensionality reduction and clustering, in order to obtain a unique mapping from vectorized chemical structures to class labels as