Next, we calculated Euclidean distances between each parent and progeny drugs in both Mol2Vec and ESR representations. In order to provide a common scale for these molecules' similarity, we took the following steps: (i) in either of the representations, the distance matrix (i.e., the matrix of distances between parents and progenies) was divided by its largest element (the largest distance); (ii) such normalized distances, dij, between parent i and progeny j, were subjected to a non-linear transformation = 1 + 100 ⋅ where factor of 100 was introduced to increase the "contrast"