Why each time algorithm "interior point" is shown in output even if I use different algorithm?

My fitness function is as below:

function out=myfitness(b)
  u = [1 2 3 4];
  out1 = u-b;             
  out = sum(out1.^2,2);
end

When I use the following code

clear all
clc

 FUN = @myfitness;
 %OPTIONS =optimoptions('fmincon','Algorithm','sqp'); % For SQP
 %OPTIONS =optimoptions('fmincon','Algorithm','sqp-legacy'); % For SQP-Legacy
 %OPTIONS =optimoptions('fmincon','Algorithm','trust-region-reflective'); % For Trust-region reflective
 OPTIONS =optimoptions('fmincon','Algorithm','active-set'); % For Active Set
 
 xo = [pi/2 pi/2 pi/2 pi/2];   % Starting point
%[x,fval] = patternsearch(ObjectiveFunction,x0); % For patternsearch
[x,fval,exitflag,output]= fmincon(FUN,xo);

It gives me my result. But when I check output variable "output", I see that each time "interior-point" is written in the algorithm inspite of the fact I use active-set or sqp or sqp-legacy i.e.,

output = 

  struct with fields:

         iterations: 2
          funcCount: 15
    constrviolation: 0
           stepsize: 2.9075
          algorithm: 'interior-point'
      firstorderopt: 3.9890e-08
       cgiterations: 0
            message: 'Local minimum found that satisfies the constra…'
            
            

Why it is so?

Answer 1

[Alan Weiss]

You didn't pass the options to fmincon.

[x,fval,exitflag,output]= fmincon(FUN,xo,[],[],[],[],[],[],[],OPTIONS);

Alan Weiss

MATLAB mathematical toolbox documentation

[Sadiq Akbar]

Thank you very much dear Alan Weiss for your guidance. Yes, you are right. Now it works. Thank you very much once again. But now there is a problem. it gives error when I un-comment the following:

OPTIONS =optimoptions('fmincon','Algorithm','trust-region-reflective'); % For Trust-region reflective

and it works for all other options. So what to do now?

[Alan Weiss]

The 'trust-region-reflective' algorithm requires you to provide a gradient in the objective function. For details, see Including Gradients and Hessians. For an example, see Include Gradient.

Alan Weiss

MATLAB mathematical toolbox documentation

[Sadiq Akbar]

Thanks for your guidance dear Alan Weiss. Last two questions.

1. Each time when run the code, about the following message is displayed in command window:

Local minimum found that satisfies the constraints.

Optimization completed because the objective function is non-decreasing in

feasible directions, to within the default value of the optimality tolerance,

and constraints are satisfied to within the default value of the constraint tolerance.

<stopping criteria details>

Can we suppress this message from displaying each time?

2.Can I change the default tolerance and set it to my desired value in options? if yes, then how?

[Walter Roberson]

option 'display', 'none'

[Alan Weiss]

For more details on options and tolerances, see Set Options. In particular, see Set and Change Options and Options in Common Use: Tuning and Troubleshooting.

Alan Weiss

MATLAB mathematical toolbox documentation

[Sadiq Akbar]

Thanks dear Walter Roberson. Yes, you are right. It works. But what about the 2nd question?

[Walter Roberson]

I will not be at my desk for several hours; I answered the part that I knew from memory.

[Sadiq Akbar]

Ok thanks to both of you dear Alas Weiss and Walter Roberson.