fmincon unidentified variable in objective function

Hi, I am running a fmincon code to optimize a function. However in my objective function an error occurs that says I have a undefined variable 'x'.

This is however what I want to optimize. Does anyone see what I am doing wrong?

%= [x1 x2 x3 w1 y1 w2 y2 w3 w4]=[v1 v2 v3 v4 v5 v6 v7 v8 v9]
%objective = min 150x1+230x2+260x3+238y1-170w1+210y2-150w2-36w3-10w4
% all constraints are inequality and should all be smaller then
% multiply greater than by -1

FUN= 150*x(1)+230*x(2)+260*x(3)+238*x(5)-170*x(4)+210*x(7)-150*x(6)-36*x(8)-10*x(9);
%FUN= @v 150*v(1)+230*v(2)+260*v(3)+238*v(5)-170*v(4)+210*v(7)-150*v(6)-36*v(8)-10*v(9);
x0=[50,50,50,50,50,50,50,50,50]; 
A=[ 1 1 1 0 0 0 0 0 0; -2.5 0 0 1 -1 0 0 0 0;0 -3 0 0 0 1 -1 0 0;0 0 -20 0 0 0 0 1 1;0 0 0 0 0 0 0 1 0];
b=[500;-200;-240;0;6000];
lb=[zeros(1,9)];
ub=[];
sol = fmincon(FUN,x0,A,b,[],[],lb,ub)

Thanks

Answer 1

[Matt J]

This should fix it,

FUN= @(x)150*x(1)+230*x(2)+260*x(3)+238*x(5)-170*x(4)+210*x(7)-150*x(6)-36*x(8)-10*x(9);

however, you should really consider using linprog instead. fmincon is overkill for such a simple linear problem.

[bus14]

thanks, this worked indeed.

I first tried it with linprog. However, in that case no solution was found: Matlab stated Problem is unbound. While it is the same problem as I in this case.

I have no clue why this does work in fmincon and not in linprog. Would you have any idea?

[Matt J]

I get the same results from both linprog and fmincon.

[John D'Errico]

Yep. bus14 asked the same question again. I showed that the vector

  120
   80
  300
  100
    k
    0
    k
 6000
    0

yields an arbitrarily large negative result for any positive k, is always feasible, and clearly satisfies the bound constraints.

[Matt J]

I think there's a discrepancy between the two threads. I get a bounded solution (the same one) and exitflag=1 with both solvers.