MATLAB: Error for ‘fmincon’ for global optimization

Question

Hello everyone.

I am running 'fmincon' for global optimization but some errors are occured.

The below is the code that I put

%%
P = [];
P = P.';
x0 = ones(243,1); 
TP = []; 
lb = zeros(243,1); 
ub = ones(243,1); 
aeq =[]; 
beq=[]; 
nonlcon_fmincon = [@nonlinearcon]; % Non-linear constraint we used for MOLP is stored in @nonlinearcon function
opts_mincon =optimoptions(@fmincon,'MaxFunctionEvaluations', 100000000000,'ConstraintTolerance',1e-5);
%% 
rng default
gs = GlobalSearch;
C = [123935;85425;96389;79871;138338;.....;27614];
C = C.';
fun_C = @(x)-C*x;
problem = createOptimProblem('fmincon','nonlcon',nonlcon_fmincon,'x0',x0,'objective',fun_C,'LB',lb,'UB',ub);
x = run(gs,problem);

The error messages are follows;

Error : createOptimProblem (line 107)
No field LB exists for PROBLEM structure.
Type "help createOptimProblem" for a list of valid fields for each solver.
Error: Untitled (line 18)
problem = createOptimProblem('fmincon','nonlcon',nonlcon_fmincon,'x0',x0,'objective',fun_C,'LB',lb,'UB',ub)

I don't know which one has problem.

Thanks

Answer 1

It's a case sensitivity issue. Instead of 'LB' and 'UB', pass in 'lb' and 'ub'.