       • To: mathgroup at smc.vnet.net
• Subject: [mg69747] Re: [mg69703] question about NDelayDSolve
• From: "Chris Chiasson" <chris at chiasson.name>
• Date: Fri, 22 Sep 2006 01:04:17 -0400 (EDT)
• References: <200609211129.HAA07703@smc.vnet.net>

```Is that like a version of DSolve that holds its arguments?

On 9/21/06, aitor69gonzalez at gmail.com <aitor69gonzalez at gmail.com> wrote:
> Hello,
>
> I am using NDelayDSolve to solve a set of delay differential equations
> that oscillate (see below). I have noticed that the range of
> integration (either limit1=400 or limit2=1000) of this function exerts
> a big influence on the result. This leads me to ask you, which is the
> best result if any? Could you give me some tips on how to use this
> function rigorously?
>
> This is the code:
>
> SetDirectory["/your/mathematica/package/directory"];
> << NDelayDSolve.m
> a = 4.5; b = 0.23; c = 0.23; k = 33; p0 = 40; Tm = 15; Tp = 2; limit1 =
> 400; \
> limit2 = 1000;
> range1 = NDelayDSolve[{p'[t] == a*m[t - Tp] - b*p[t],
>         m'[t] == k/(1 + (p[t - Tm]^2/p0^2)) - c*m[t]}, {m -> (0 &),
>         p -> (0 &)}, {t, 0, limit1}, AccuracyGoal -> 0, PrecisionGoal
> -> 0];
> range2 = NDelayDSolve[{p'[t] == a*m[t - Tp] - b*p[t],
>         m'[t] == k/(1 + (p[t - Tm]^2/p0^2)) - c*m[t]}, {m -> (0 &),
>         p -> (0 &)}, {t, 0, limit2}, AccuracyGoal -> 0, PrecisionGoal
> -> 0];
> Plot[{Evaluate[p[t] /. range1], Evaluate[p[t] /. range2]}, {t, 0,
> limit1},
>   PlotStyle -> {RGBColor[0, 1, 0], RGBColor[1, 0, 0]}]
>
>

--
http://chris.chiasson.name/

```

• Prev by Date: Re: does the following code shut down anyone else's kernel? - why?
• Next by Date: Re: Split a file into multiple files using a pattern