Re: NDSolve plot problem
- To: mathgroup at smc.vnet.net
- Subject: [mg79331] Re: NDSolve plot problem
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Wed, 25 Jul 2007 02:00:04 -0400 (EDT)
- Organization: The Open University, Milton Keynes, UK
- References: <f84iqn$oqj$1@smc.vnet.net>
Jake Trexel wrote:
> Needing help with plots of equations.
> I have the following eqs and I get a nice plot. But what I want is for the
> same plot to continue for 3 to 4 times and then a negative plot at then
> end. How do I go about this?
>
> thank you
> Jake
> i[t_] := If[t < 10 || t > 60, 0, 1]
>
> Plot[i[t], {t, 0, 100}, AxesLabel -> {"t = time", "i = current"}]
>
> RCSoln[R_, c_: 1, v0_: 0] :=
> NDSolve[{v'[t]==1/c{i[t]-v[t]/R},v[0]==v0,}t,0,100}]
> Plot[Evaluate[v[t]/. {RCSoln[2]}],{t,0,100}]
Hi Jake,
Do you have something like this in mind?
i[t_] := If[10 <= t <= 60 || 110 <= t <= 160 || 210 <= t <= 260, 1,
If[310 <= t <= 360, -1, 0]]
Plot[i[t], {t, 0, 400}, AxesLabel -> {"t = time", "i = current"}]
RCSoln[R_, c_: 1, v0_: 0] :=
NDSolve[{v'[t] == 1/c (i[t] - v[t]/R), v[0] == v0}, v, {t, 0, 400}]
Plot[Evaluate[v[t] /. {RCSoln[2]}], {t, 0, 400},
AxesLabel -> {"t = time", "v = voltage"}]
Regards,
Jean-Marc