H infinity norm command

Hello, Please can somebody write a command in matlab for calculating H infinity norm for the following system: dz/dt=Az(t)+Bu(t)+Fw(t) y(t)=Cz(t)+Du(t) where A,B,C,F,D real value 2x2 matrices I have the following command but it is not working

A = [0 2; 8 1] B = [1 0; 2 1] F = [-1 2; -4 3] C = [2 0; 0 1] D = [1 0; 0 0] sys = ss(A,B,F,C,D);

 norm(sys,inf)
Thanks for advance everybody

[Abhisek Roy]

Hello Oleg,

Have you tried the 'hinfnorm' command? Have a look at this command, it might be helpful.

Regards, Abhisek

[Oleg Kelis]

The hinfnorm Does not working. I think the problem is in deffinition of my system in matlab. Does Matlab has a syntax for my system? I know just ss and dss and they does not working Thanks