Date: Dec 20, 2011 2:53 AM
Author: wan
Subject: Optimization terminated: No feasible solution found.

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!