Lévy-Flight Krill Herd Algorithm

Algorithm 1

Local Lévy-flight (LLF) operator.

Begin

  𝑎=𝐴/(𝑡^∧2);   % Smaller step for local walk

  NoSteps = 𝑑∗exprnd2∗𝑡_max;

  Determine the next step size 𝑑𝑥 by performing Lévy flight as shown in Section 2.2;

  𝑟=⌈NP∗rand⌉

  for 𝑗=1 to d  do

     if  rand ≤ 0.5   % Random number to determine direction

       𝑉_𝑖(𝑗)=𝑎×𝑑𝑥(𝑗)+𝑋_NP−𝑟+1(𝑗)

     else

         𝑉_𝑖(𝑗)=𝑎×𝑑𝑥(𝑗)−𝑋_NP−𝑟+1(𝑗)

     end if

  end for  j

  Evaluate the offspring 𝑉_𝑖

  if 𝑉_𝑖 is better than 𝑋_𝑖  then

         𝑋_𝑖=𝑉_𝑖

  end if

End.