Similarity maps for machine-learning methods. Similarity map of molecule 2 (top) and molecule 3 (bottom) using RF(Morgan2) (left) and NB(Morgan2) (right). Color scheme: removing bits decreases similarity (i.e. positive difference) (green), no change in similarity (gray), removing bits increases similarity (i.e. negative difference) (pink). The bit-vector size of Morgan2 was 1024 bits.