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Topic: Optimization terminated: No feasible solution found.
Replies: 5   Last Post: Jan 19, 2014 11:18 AM

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s.cahyaningtias@gmail.com

Posts: 1
Registered: 1/19/14
Re: Optimization terminated: No feasible solution found.
Posted: Jan 19, 2014 12:48 AM
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Dear Marcello,
I have same case 'nofeasible solution' then I have tried your suggestion but there is still no feasible solution?
Is my case really infeasible?
what do you think?
Sari C.
Pada Rabu, 21 Desember 2011 1:15:44 UTC+7, Marcelo Marazzi menulis:
> Hi:
>
>
>
> That is not an error, it's rather an exit message that indicates that
>
> the fmincon was not able to find a feasible point (a value of the vector
>
> x that satisfies all of the constraints).
>
>
>
> Now, this means that either the problem is really infeasible, or that
>
> it's feasible but the solver was not able to find a feasible point.
>
>
>
> You may want to try another algorithm in fmincon to compare results.
>
> Set
>
>
>
> options = optimset('Algorithm','interior-point');
>
>
>
> and call fmincon as you do below. It's normaly also a good idea to set
>
> the option Display to 'iter' in order to see more details of the run.
>
>
>
> The section When the Solver Fails in the documentation provides guidance
>
> on next steps that you may want to try:
>
> http://www.mathworks.com/help/toolbox/optim/ug/br44iv5-1.html
>
>
>
> -Marcelo
>
>
>
> On 12/20/2011 2:53 AM, wan wrote:
>

> > Friends,
>
> > I try to run a program by fmincon,but I got an error:Optimization
>
> > terminated: No feasible solution found.Search direction less than
>
> > 2*options.TolX but constraints are not satisfied.and I don't know what
>
> > is my mistake...
>
> > "myfun.m"
>
> > function f=myfun(x)
>
> > f=2.20*x(1)*(x(1)-1)^2/(x(1)-2)+2.20*x(1)*x(2)*(x(2)-1)^2/(x(2)-2)+2.42*x(1)*x(2)*x(3)*(x(3)-1)^2/(x(3)-2)+2.75*x(1)*x(2)*x(3)*x(4)*(x(4)-1)^2/(x(4)-2);
>
> >
>
> > and "mycon2.m"
>
> > function[c,ceq]=mycon2(x)
>
> > g(1)=1-(x(2)*(x(1)-2)/(x(2)-2))^1/3*(x(2)-1)/(x(1)-1);
>
> > g(2)=(x(2)*(x(1)-2)/(x(2)-2))^1/3*(x(2)-1)/(x(1)-1)-1.2;
>
> > g(3)=1-(1.1*x(3)*(x(2)-2)/(x(3)-2))^1/3*(x(3)-1)/(x(2)-1);
>
> > g(4)=(1.1*x(3)*(x(2)-2)/(x(3)-2))^1/3*(x(3)-1)/(x(2)-1)-1.2;
>
> > g(5)=1-(1.13636*x(4)*(x(3)-2)/(x(4)-2))^1/3*(x(4)-1)/(x(3)-1);
>
> > g(6)=(1.13636*x(4)*(x(3)-2)/(x(4)-2))^1/3*(x(4)-1)/(x(3)-1)-1.2;
>
> > c=[g(1);g(2);g(3);g(4);g(5);g(6)];
>
> > ceq=[1590.192-x(1)*x(2)*x(3)*x(4)];
>
> > command window:
>
> >>> x0=[7.2 7.2 7.5 4.09];
>
> >>> lb=[4;5;5;4];
>
> >>> ub=[8;8;8;5.6];
>
> >>> options=optimset('largescale','off','maxfunevals',1000000);
>
> >>> [x,fval]=fmincon(@myfun,x0,[],[],[],[],lb,ub,@mycon2,options)
>
> > when I try to run the script, I get these messages errors:
>
> > Optimization terminated: No feasible solution found.
>
> > Search direction less than 2*options.TolX but constraints are not
>
> > satisfied.
>
> > x =
>
> >
>
> > 15.7056 10.0989 -2.7056 -3.7056
>
> >
>
> >
>
> > fval =
>
> >
>
> > -9.8284e+003
>
> > Any help is very much appreciated.Wish you a nice day!




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