Defining and calling functions in matlab

Hi, am trying to defing the fuction pasted below in a separate file and then call it in another script saved in a different file. the function is nothing but just the log-likelihood fuction of Weibull distribution function. However am getting error that have also pasted below. What can be possibly wrong? Am using R2018a, Please help.

this was my trial

function out = wbl(X)

n=numel(X)

A1=X(:,1);

A2=X(:,2);

%objective function

fx=n*log(A1)-n*log(A2)-sum((X./A2).^A1)+(A1-1)*sum(log(X))

%define penalty term

end

the error that I got is pasted below

Output argument "out" (and maybe others) not assigned during call to "wbl2".

Error in Gwo7 (line 20)

fx=fun(pos);

the corresponding script that i called the function in, is pasted below

clear all

clc

format short

fun = @wbl2;

X=rand(34,2)

N=300;

D=2;

lb=[0 0];

ub=[1 1];

itermax=500;

%generating intial popilation size

for i=1:N

for j=1:D

pos(i,j)=lb(j)+rand.*(ub(j)-lb(j));

end

end

%Evaluation of objective function

fx=fun(pos);

[fminvalue,ind]=min(fx);

% GWO main loop

iter=1;

while iter<=itermax

Fgbest=fminvalue;

a=2-2*iter/itermax;

for i=1:N

X=pos(i,:);

pos1=pos;

A1=2.*a.*rand(1,D)-a;

C1=2.*rand(1,D);

[alpha, alphaind]=min(fx);

alphapos=pos1(alphaind,:);

Dalpha=abs(C1.*alphapos-X);

X1=alphapos-A1.*Dalpha;

pos1(alphaind,:)=[];

fx1=fun(pos);

%finding beta position

[bet,betind]=min(fx1);

betpos=pos1(betind,:);

A2=2.*a.*rand(1,D)-a;

C2=2.*rand(1,D);

Dbet=abs(C2.*betpos-X);

X2=betpos-A2.*Dbet;

pos1(betind,:)=[];

fx1=fun(pos1);

%Delta position

[delta,deltaind]=min(fx1);

deltapos=pos1(deltaind,:);

A3=2.*a.*rand(1,D)-a;

C3=2.*rand(1,D);

Ddelta=abs(C3.*betpos-X);

X3=deltapos-A3.*Ddelta;

Xnew=(X1+X2+X3)./3;

%check bound

Xnew=max(Xnew,lb);

Xnew=min(Xnew,ub);

fnew=fun(Xnew);

%greedy slection

if fnew<fx(i)

pos(i,:)=Xnew;

fx(i,:)=fnew;

end

end

%Update Gbest

[fmin,find]=min(fx);

if fmin<Fgbest

Fgbest = fmin;

gbest=pos(find,:);

end

%memorize

[optval,optind]=min(fx);

BestFx(iter)=optval;

BestX(iter,:)=pos(optind,:);

%show iteration infomation

plot(BestFx, 'LineWidth',2);

iter=iter+1

end

out=BestX

Answer 1

[Matt J]

function fx =  wbl(X)

Answer 2

[Image Analyst]

Your script calls wbl2, not wbl. And your original wbl function

function out =  wbl(X)
n=numel(X)
A1=X(:,1);
A2=X(:,2);
%objective function
fx=n*log(A1)-n*log(A2)-sum((X./A2).^A1)+(A1-1)*sum(log(X))
%define penalty term
end

never assigns "out" though it tries to return it. That's what gives the error

So, what is out? Is if fx? If so you can either do

function out =  wbl(X)
n=numel(X)
A1=X(:,1);
A2=X(:,2);
%objective function
out = n*log(A1)-n*log(A2)-sum((X./A2).^A1)+(A1-1)*sum(log(X))
%define penalty term
end

or send out fx instead of out.

function fx =  wbl(X)
n=numel(X)
A1=X(:,1);
A2=X(:,2);
%objective function
fx = n*log(A1)-n*log(A2)-sum((X./A2).^A1)+(A1-1)*sum(log(X))
%define penalty term
end

[okoth ochola]

Thank you both, I was not seeing that, my hands were typing incorrrect things, not what was in my mind. Thanks alot am forever grateful

[Image Analyst]

You're welcome. I'm glad my explanation helped you understand how it works, and why yours didn't work. Thanks for voting for, and accepting, the answers. 🙂

[Matt J]

The vote was mine. I'm not sure @okoth ochola knows about upvoting.