Failure in initial objective function evaluation when I'm solving a linear programming.

I'm solving this question above and my code is below:

This is my coding in first file

 function z= myobj01(x)
x= -3*x(1)-4*x(2);
 end

And this is my coding in second file

 fun= @myobj01;
x0=[0,1];
A=[1 1; 1 2; 0 1];
b=[6;8;3];
Aeq=[]; beq=[];
lb=[0,0]; ub=[];

[x,fval]=fmincon(fun,x0,A,b,Aeq,beq,lb,ub)

The problem is occuring in my second coding

It shows

Output argument "z" (and maybe others) not assigned during call to "myobj01".

Error in fmincon (line 535)
      initVals.f = feval(funfcn{3},X,varargin{:});

Error in myobj02 (line 8)
[x,fval]=fmincon(fun,x0,A,b,Aeq,beq,lb,ub)

Caused by:
    Failure in initial objective function evaluation. FMINCON cannot continue.

When I run the second coding.

May I ask, where's the problem?

Answer 1

[Stephan]

Use:

function z= myobj01(x)
z= -3*x(1)-4*x(2);
end

[Ksss]

Thanks!