plot water level(at fixed point) vs time

hello guys, I am drawing water level h at nodes i (I use finite volume method) where i=1:m

so, the equation is h(i)=h(i)-(dt/dx)*(F1(i+1)-F1(i)); and the drawing code is

 plot(h+Zb,'-')
    hold on
    plot(Zb,'-')
    axis([0 m 0 5])

if I wanna draw the water level at i=100(fixed point) during time period where total time is tmax and time step is dt.

how can I do it? I know it is simple but I feel confused

Answer 1

[Basheer]

?