You need to call your ‘h4_5’ equation correctly using function handle syntax (adding the ‘@’ sign) in your ode45 call. Then recognising that you want to plot the columns of the ‘q’ matrix ode45 returns, you have to address them as such.
With these minor changes, this works:
[t,q]=ode45(@h4_5,[0 200],[0 1 0]);
plot3(q(:,1),q(:,2),q(:,3),'b')
view(-10,10)
xlabel('x')
ylabel('y')
zlabel('z')
grid on
I added the grid call.
Also, note that conv is a MATLAB bulit-in function for convolution. It doesn’t make any difference here because you’re not using it otherwise in your ODE function and a function workspace is unique to it, but it’s best to avoid using any function name as a variable name. This is called ‘overshadowing’ and can cause serious problems in your code, because MATLAB will use the variable definition rather than the function definition if you have already used a specific name as a variable.
