Fmincon solution is same as initial guess

Hello,

My Fmincon function does not minimize the cost function, instead, it reports the same initial guess provided to it. Please help with recommendations to the piece of code below:

function J=cost_function(y)

for i=1:size(a,1)
    AA = y0*b(i,:)';
    BB = y0*c(i,:)';
    CC = (y0(1).*c(i,1)/BB)*c(i,1) + (y0(2).*c(i,2)/BB)*c(i,2);
    DD = y0*d(i,:)';
    EE = y0*e(i,:)';
    all(i,:)=[AA, BB, CC, DD, EE];
end
     
    J=sum(abs(all(1,:) - x(1:5)') ./ x(1:5)')^2;
    

The script calculates the a, b, c, d, e,....... and passes them to the function along with "y0".

Please advise, and thanks in advance

Answer 1

[Sulaymon Eshkabilov]

THere are a couple of errs oin your fcn, i.e. y0, a,b,c,d not defined. Moreover, x is not defined.

function J=cost_function(y0, a, b, c, d, e, x)  

for i=1:size(a,1)
    AA = y0*b(i,:)';
    BB = y0*c(i,:)';
    CC = (y0(1).*c(i,1)/BB)*c(i,1) + (y0(2).*c(i,2)/BB)*c(i,2); % Check: multiplied and divided by c(i,1) and c(i,2)
    DD = y0*d(i,:)';
    EE = y0*e(i,:)';
    all(i,:)=[AA, BB, CC, DD, EE];
end
     
    J=sum(abs(all(1,:) - x(1:5)') ./ x(1:5)')^2;
    

[Samy Alkhayat]

All of these are defined in the script that calls the function. Should they be defined inside the function?

[Sulaymon Eshkabilov]

yes.

[Samy Alkhayat]

Thank you very much.

[Sulaymon Eshkabilov]

Most welcome!