Asteroids with a previously known Mahlke class (represented by the corresponding letter markers) in the LDA space of the three most significant variables. The LDA shows clear groups of S, M, and C/Ch/P asteroids. D and Ch asteroids are separated with LDA-2, but not LDA-3. While LDA-3 improves the classification success rates (Sect. 3.3), it is not visually noticeable. The number of asteroids in each class is: S = 116, Ch = 54, C = 48, P = 33, M = 23, D = 16, V = 10, A = 7, L = 6, K = 5, Z = 4, E = 3, B = 2, and Q = 1.