Matlab code for Remora Optimization algorithm

Initialization

function Pos=init(SearchAgents,dimension,upperbound,lowerbound)

Boundary= size(upperbound,2); 

if Boundary==1

    Pos=rand(SearchAgents,dimension).*(upperbound-lowerbound)+lowerbound;

end

if Boundary>1

    for i=1:dimension

        ub_i=upperbound(i);

        lb_i=lowerbound(i);

        Pos(:,i)=rand(SearchAgents,1).*(ub_i-lb_i)+lb_i;

    end

end

ROA

function [Score,BestRemora,Convergence]=ROA(Search_Agents,Max_iterations,...

    Lowerbound,Upperbound,dimensions,objective)

tic;       

BestRemora=zeros(1,dimensions);

Score=inf; 

Remora=init(Search_Agents,dimensions,Upperbound,Lowerbound); % Generate initial remora population

Prevgen{1}=Remora; 

Convergence=zeros(1,Max_iterations);

t=0;

while t<Max_iterations  

    

%% Memory of previous generation

    if t<=1

        PreviousRemora = Prevgen{1};

    else

        PreviousRemora = Prevgen{t-1};

    end

    

% Boundary check

    for i=1:size(Remora,1)

        Flag4Upperbound=Remora(i,:)>Upperbound;

        Flag4Lowerbound=Remora(i,:)<Lowerbound;

        Remora(i,:)=(Remora(i,:).*(~(Flag4Upperbound+Flag4Lowerbound)))+Upperbound.*Flag4Upperbound+Lowerbound.*Flag4Lowerbound;

        fitness=objective(Remora(i,:));

        

 % Evaluate fitness function of search agents   

 

if fitness<Score 

            Score=fitness; 

            BestRemora=Remora(i,:);

        end

        

    end

    

  % Make a experience attempt through equation (2)

  

    for j=1:size(Remora,1)

        RemoraAtt = Remora(j,:)+(Remora(j,:)-PreviousRemora(j,:))*randn;                    %Equation(2)

        

  % Calculate the fitness function value of the attempted solution (fitnessAtt)

  

        fitnessAtt=objective(RemoraAtt);

        

  % Calculate the fitness function value of the current solution (fitnessI)

  

        fitnessI=objective(Remora(j,:));

        

  % Check if the current fitness (fitnessI) is better than the attempted fitness(fitnessAtt)

  % if No, Perform host feeding by equation (9)

  

        if fitnessI>fitnessAtt

            V = 2*(1-t/Max_iterations);                                                     % Equation (12)

            B = 2*V*rand-V;                                                                 % Equation (11)

            C = 0.1;

            A = B*(Remora(j,:)-C*BestRemora);                                               % Equation (10)

            Remora(j,:)= Remora(j,:)+A;                                                     % Equation (9)

            

  % If yes perform host conversion using equation (1) and (5)       

  

        elseif randi([0 1],1)==0

            a=-(1+t/Max_iterations);                                                        % Equation (7)

            alpha = rand*(a-1)+1;                                                           % Equation (6)

            D = abs(BestRemora-Remora(j,:));                                                % Equation (8)

            Remora(j,:) = D*exp(alpha)*cos(2*pi*a)+Remora(j,:);                             % Equation (5)

        else 

            m=randperm(size(Remora,1));

            Remora(j,:)=BestRemora-((rand*(BestRemora+Remora(m(1),:))/2)-Remora(m(1),:));   % Equation (1)

        end

    end

    

  t=t+1 ;

  fprintf('Iteration : %d, best score : %d\n',t,Score)

  Prevgen{t+1}=Remora; 

  Convergence(t)=Score;

    end   

end

Main code

clc

clear

close all;

% Initialize algorithm paramaters

SearchAgents=50; 

Fun_name='F1';  

Max_iterations=100; 

[lowerbound,upperbound,dimension,fitness]=fun_info(Fun_name);

% Remora Optimization

[Best_score,Best_pos,ROA_curve]=ROA(SearchAgents,Max_iterations,lowerbound,upperbound,dimension,fitness);

display(['The best solution obtained by ROA is : ', num2str(Best_pos)]);

display(['The best optimal value of the objective funciton found by ROA is : ', num2str(Best_score)]);

% Display the convergence curve

figure;

plot(ROA_curve,'-b','linewidth',2)

xlabel('Iterations')

ylabel('Fitness Value')

set (gca,'fontweight','Bold','Fontname','Times')