Fig. 5 in Empirical mode decomposition applied to acoustic detection of a cicadid pest

Fig. 5. Representation of the sets P and Q in the Cartesian plane and in PP, both with two classes. (a) The set P of vectors is linearly separable; (b) The set Q is not linearly separable. (c) PP representing the sets P and Q through PFE, suggesting a simple and a robust classifier for P and Q, respectively. The example is only illustrative and not related to the sets analyzed in this paper.