How can I plot arrows over a function? (For ODE solution)

Hi! I want to plot arrows over a function , for example if I have a Sin(x) function, plot the arrows and its directions.

Maybe I'm not clear, so I'll let an example down here.

I've tried using quiver() but I cant get the results as the image below.

Thanks a lot.

Answer 1

[Star Strider]

Try this:

t = linspace(0, 2, 25);
h = t(2)-t(1);
s = sin(2*pi*t/max(t));
ds = gradient(s,h);
dt = gradient(t,h);

figure
quiver(t,s, dt,ds)
grid

producing:

This calculates the derivative from the data (here sin(t)). You may be able to recover your derivative directly from your ODE, so you may not need to calculate the gradient of your solved vector. I will leave that for you to determine.