fig5

Figure 5. The process of descriptor construction by extreme feature engineering. The x_i (i = 1, 2, … n) indicates the chosen feature. The parameters following the arrows denote the constructed a large number of brand-new descriptors. These 9 functions of x, x^-1, , x², x³, e^x, ln|x|, ln(1 + |x|) and log|x| are employed in the nonlinear conversion of features. All of the descriptors mixed in a nonlinear way to construct more descriptors.