How to use trigonometric in state space(ss command)

Hello everyone, I am a student studying nonlinear control I am stuck on how to switch -x1 at the last line into -sin(x1) Can anyone kindly tell me how to achieve it? Tons of thanks :)

    % code
A=[0 1;-1 -2];
B=[0 0;0 5];
C=[1 0];
D=0;
T=ss(A,B,C,D)
tf(T)
step(tf(T),15);

[nl2605]

You mean one of the coefficients is a function of 'x1'? Is it?

[Jay Huang]

yeah. In simple, the original is x2'=x1 now I want x2'=sin(x1) but I have no idea how to change it at ss

[nl2605]

Wow! that fails me completely! I can't understand either how can we change it.

[Jay Huang]

It is doable if we just use ode45. I still want to know it XD. Thanks for your answering though!

[nl2605]

You could do it using ode45?? How? Could you throw some light? Or do you just know that it can be done but not how!

[Jay Huang]

I has just done it yesterday. referring to This vid