Fig. 2.

Hypothetical pattern classification problem between subjects (red circles) and controls (blue circles). Each symbol (circle) represents the brain scan of a different subject. (a) Using different pattern classification methods, it is possible to obtain several different classifiers that correctly separate the two groups; these are represented by lines. (b) Using SVM, an optimal classifier is obtained as represented by the red dashed line and the support vectors are represented by arrow symbols.

Reproduced with permission (Orrù et al., 2012).