One way to represent classifiers. Given classes $ w_1, w_2, \ldots, w_k $ and feature vector x, which is in n-dimensional space, the discriminant functions $ g_1(x), g_2(x), \ldots, g_k(x) $ where $ g_\#(x) $ maps n-dimensional space to real numbers, are used to make decisions. Decisions are defined as $ w_\# $ if $ g_\#(x) >= g_j(x) $ for all j.
Discriminant functions are used to define Decision Surfaces_Old Kiwi.
