Revision history [back]

You can do this using desolve_odeint. I'm not sure why it's not working in desolve_rk4. Try this:

var('t s V')
def f(t):
    if t<5:
        return 3
    else:
        return 0
def rhs(V,s,t):
    return ((f(t)-V)/(2.3*1.2))
F=[SR(1),rhs]
tlist=srange(0,10,0.1)
ans=desolve_odeint(F,[0,10],tlist,[s,V],ivar=t)
line(ans)