Table 2.

Multimodal function.

Function	Dim	Range	f min
$f_4=\sum _{i=1}^n\left[x_i^2-10\cos \left(2\pi x_i\right)\right]+10$	30	[-5.12,5.12]	0
$f_5=-20\exp \left(-0.2\sqrt{\frac{1}{n}\sum _{i=1}^n{x}_i^2}\right)-\exp \left(\frac{1}{n}\sum _{i=1}^n\cos \left(2\pi x_i\right)\right)+20+e$	30	[-32,32]	0
$f_6=\frac{1}{4000}\sum _{i=1}^n{x}_i^2-\prod _{i=1}^n\cos \left(\frac{x_i}{\sqrt{i}}\right)+1$	30	[-600,600]	0