Re: question about NDelayDSolve

*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? > Thank you in advance. > > 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/

**References**:**question about NDelayDSolve***From:*aitor69gonzalez@gmail.com