A Novel Hybrid Self-Adaptive Bat Algorithm

Algorithm 3

DE_Strategy function.

Input:  𝑛th position in the trial solution, indexes of virtual bats 𝑖,𝑟₁,𝑟₂,𝑟₃,𝑟₄.

Global: Population 𝐱_𝐢=𝑥_𝑖1,…,𝑥_𝑖𝐷,𝐴,𝑟^𝑇 for 𝑖=1,…,𝑁𝑝,STRATEGY.

Output: Modified value of the trial solution 𝑧.

 (1)    switch (STRATEGY)

 (2)   case DE/rand/1/bin:

 (3)   𝑧=𝑥_𝑟1,𝑛+𝐹∗(𝑥_𝑟2,𝑛−𝑥_𝑟3,𝑛);

 (4)   case DE/randToBest/1/bin:

 (5)   𝑧=𝑥_𝑖,𝑛+𝐹∗(best_𝑛−𝑥_𝑖,𝑛)−𝐹∗(𝑥_𝑟1,𝑛−𝑥_𝑟2,𝑛);

 (6)   case DE/best/2/bin:

 (7)   𝑧=best_𝑛+𝐹∗(𝑥_𝑟1,𝑛+𝑥_𝑟2,𝑛−𝑥_𝑟3,𝑛−𝑥_𝑟4,𝑛);

 (8)   case DE/best/1/bin:

 (9)   𝑧=best_𝑛+𝐹∗(𝑥_𝑟1,𝑛−𝑥_𝑟2,𝑛);

 (10) end switch

 (11) return  𝑧;