ODE23 taking in 3 variables

I can run this function with 2 z values but when I try to add another z value I get an error. Do you know how to run this function for 3 z values?

Error: Index exceeds matrix dimensions.

 function dxdy = TY3(t,z)
 dxdy = [z(3); 1*z(3)+2*z(2)+3*z(1)];

 [t,z] = ode23(@TY3,[0 30],[1 0 ]);
 plot(t,z(:,1),'k','LineWidth',2);

Answer 1

[Azzi Abdelmalek]

You have 3 variables z(1),z(2) and z3, you need to write 3 equations dydx(1),dydx(2) and dydx(3), for example

dxdy = [z(3); 1*z(3)+2*z(2)+3*z(1);0]

and call ode23 with 1x3 array representing initial conditions

[t,z] = ode23(@TY3,[0 30],[1 0 1 ]);
plot(t,z(:,1),'k','LineWidth',2);

[WhatIsMatlab-]

Well that allows it run. Thank you. It didn't produce what I expected but at least it does now run. That's progress.

[Azzi Abdelmalek]

I just gave an example, you have to provide the third equation and the initial conditions

[WhatIsMatlab-]

Ok thanks!! I got it working.