where g denotes the logistic regression classifier, {} is a unique set and xi is the reaction fingerprint. To ensure that a given retrosynthesis framework proposes a variety of all 10 reaction classes, one can plot the frequency of each reaction class in a histogram q. Histogram q is a collection of all N • k predictions made by the retrosynthesis algorithm. This histogram is a discrete probability distribution representing the likelihood of drawing a specific reaction class for a random reaction. Comparing that to the reaction class distribution p of the test database, the similarity between the two distributions can be calculated through the Jensen-Shannon divergence: