Re: Delay Differential Equations
- To: mathgroup at smc.vnet.net
- Subject: [mg105256] Re: Delay Differential Equations
- From: dh <dh at metrohm.com>
- Date: Wed, 25 Nov 2009 06:14:19 -0500 (EST)
- References: <hegdlf$ku$1@smc.vnet.net>
Yun Zhao wrote:
> Hi,
>
> Does anyone have experience working with delay differential equations in
> Mathematica 7? I found some help files on wolfram and Mathematica help, but
> the information available there were very limited. If anyone can refer me to
> other online or textual sources, I would really appreciate it. Thank you
> very much.
>
> Mike
>
>
Hi,
you do not need a delayed differential equation. You simple have a rate
change somewhere in time and NDSolve can handle this nicely:
sol = p /.
NDSolve[ {p'[t] == - 0.0123 p[t] - 0.0367 If[t < 37, 0, p[t]],
p[0] == 30000}
, p, {t, 0, 120}][[1]];
Plot[sol[t], {t, 0, 120}]
cheers, Daniel Huber