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Re: Optimization terminated: No feasible solution found.
Posted:
Jan 19, 2014 12:48 AM


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','interiorpoint'); > > > > 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/br44iv51.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=[1590.192x(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!



