when i run this code it give me error Not enough input arguments. Error in GWO (line 23) Alpha_pos=zeros(1,dim);

% Grey Wolf Optimizer
function [Alpha_score,Alpha_pos,Convergence_curve]=GWO(SearchAgents_no,Max_iter,lb,ub,dim,fobj)

% initialize alpha, beta, and delta_pos
Alpha_pos=zeros(1,dim);
Alpha_score=inf; %change this to -inf for maximization problems

Beta_pos=zeros(1,dim);
Beta_score=inf; %change this to -inf for maximization problems

Delta_pos=zeros(1,dim);
Delta_score=inf; %change this to -inf for maximization problems

%Initialize the positions of search agents
Positions=initialization(SearchAgents_no,dim,ub,lb);

Convergence_curve=zeros(1,Max_iter);

l=0;% Loop counter

% Main loop
while l<Max_iter
    for i=1:size(Positions,1)  
        
       % Return back the search agents that go beyond the boundaries of the search space
        Flag4ub=Positions(i,:)>ub;
        Flag4lb=Positions(i,:)<lb;
        Positions(i,:)=(Positions(i,:).*(~(Flag4ub+Flag4lb)))+ub.*Flag4ub+lb.*Flag4lb;               
        
        % Calculate objective function for each search agent
        fitness=fobj(Positions(i,:));
        
        % Update Alpha, Beta, and Delta
        if fitness<Alpha_score 
            Alpha_score=fitness; % Update alpha
            Alpha_pos=Positions(i,:);
        end
        
        if fitness>Alpha_score && fitness<Beta_score 
            Beta_score=fitness; % Update beta
            Beta_pos=Positions(i,:);
        end
        
        if fitness>Alpha_score && fitness>Beta_score && fitness<Delta_score 
            Delta_score=fitness; % Update delta
            Delta_pos=Positions(i,:);
        end
    end
    
    
    a=2-l*((2)/Max_iter); % a decreases linearly fron 2 to 0
    
    % Update the Position of search agents including omegas
    for i=1:size(Positions,1)
        for j=1:size(Positions,2)     
                       
            r1=rand(); % r1 is a random number in [0,1]
            r2=rand(); % r2 is a random number in [0,1]
            
            A1=2*a*r1-a; % Equation (3.3)
            C1=2*r2; % Equation (3.4)
            
            D_alpha=abs(C1*Alpha_pos(j)-Positions(i,j)); % Equation (3.5)-part 1
            X1=Alpha_pos(j)-A1*D_alpha; % Equation (3.6)-part 1
                       
            r1=rand();
            r2=rand();
            
            A2=2*a*r1-a; % Equation (3.3)
            C2=2*r2; % Equation (3.4)
            
            D_beta=abs(C2*Beta_pos(j)-Positions(i,j)); % Equation (3.5)-part 2
            X2=Beta_pos(j)-A2*D_beta; % Equation (3.6)-part 2       
            
            r1=rand();
            r2=rand(); 
            
            A3=2*a*r1-a; % Equation (3.3)
            C3=2*r2; % Equation (3.4)
            
            D_delta=abs(C3*Delta_pos(j)-Positions(i,j)); % Equation (3.5)-part 3
            X3=Delta_pos(j)-A3*D_delta; % Equation (3.5)-part 3             
            
            Positions(i,j)=(X1+X2+X3)/3;% Equation (3.7)
            
        end
    end
    l=l+1;    
    Convergence_curve(l)=Alpha_score;
end

[the cyclist]

How do you call the function?

[Jan]

Please post a copy of the complete error message. Then the users do not have to guess, in which line the problem occurs.

Posting the input arguments you use, would be a good idea also to let the readers understand, what you observe. Or do you call the function without input arguments, e.g. by pressing the green triangle, the Run-button in the editor? If so: The function needs input arguments.

[essrra]

i dont understand you

[essrra]

Not enough input arguments.

Error in GWO (line 23)

Alpha_pos=zeros(1,dim);

[Steven Lord]

You have to run this code somehow in order to receive that error. Show us or tell us exactly how you run it.

• Did you type something in the Command Window or in a script file to run it? If so post exactly what you typed.
• Did you press the green triangle in the Toolstrip? If so tell us that.
• Did you do something else to run it? If so describe exactly what you did to get this code to run.

[essrra]

i clicked on run button

[Walter Roberson]

You need to click the run button in the main.m code, not the GWO code.

Answer 1

[Jan]

The function requires.these input arguments: SearchAgents_no,Max_iter,lb,ub,dim,fobj. How do you define them?

If you start the function using the Run-Button, no input arguments are defined.

[essrra]

i dont know how to define them because i statrt matlab from little time

[Walter Roberson]

This is not a function that you would call directly. You would have some code that created initial conditions and then called this function passing in the appropriate conditions.

See the main.m function at https://www.mathworks.com/matlabcentral/fileexchange/44974-grey-wolf-optimizer-gwo to get an example of how to run the code.