Re: NDSolve and plots
- To: mathgroup at smc.vnet.net
- Subject: [mg78953] Re: [mg78884] NDSolve and plots
- From: DrMajorBob <drmajorbob at bigfoot.com>
- Date: Fri, 13 Jul 2007 06:11:43 -0400 (EDT)
- References: <2677133.1184257439073.JavaMail.root@m35>
- Reply-to: drmajorbob at bigfoot.com
If I could see your code, I could be more specific, but here's a similar
situation, perhaps.
Use NDSolve:
s = First@
NDSolve[{x'[t] == -y[t] - x[t]^2, y'[t] == 2 x[t] - y[t]^3,
x[0] == y[0] == 1}, {x, y}, {t, 20}]
{x->InterpolatingFunction[{{0.,20.}},<>],y->InterpolatingFunction[{{0.,20.}},<>]}
Save the interpolating functions:
Clear[f]
Table[f[i] = s[[i, 2]], {i, 1, Length@s}];
And here's a plot:
Plot[{f[1][t], f[2]@t}, {t, 0, 20}]
Doing the same thing with your problem would save 11 functions, f[1], .. .,
f[11].
Bobby
On Thu, 12 Jul 2007 04:12:02 -0500, Nikhil Shankar
<rise.of.aybabtu at gmail.com> wrote:
> Hey guys,
>
> I'm working on a model of the heart, which can be simplified to eleven
> simultaneous differential equations... I am solving them all with
> NDSolve and explicit Runge Kutta numerical integration. I am happy with
> the results, but I don't know how to plot a single function, of the
> eleven that are solved simultaneously.
>
> I can plot all 11 of them on one graph by using
>
> Plot[Evaluate[eqs /. %], {t, 0, 10}]
>
> where eqs are all 11 functions, and the last output was the set of the
> 11 interpolating functions. Plotting all 11 pretty much has no value to
> me though.
>
> How do I store the interpolating function data for each function so I
> can plot each by itself?
>
> Also, how can I save step-by-step results using Reap/Sow?
>
> Thanks for your help guys.
>
>
--
DrMajorBob at bigfoot.com