       Re: Using NDSolve and Finding a specific Value

• To: mathgroup at smc.vnet.net
• Subject: [mg85369] Re: [mg85354] Using NDSolve and Finding a specific Value
• From: Bob Hanlon <hanlonr at cox.net>
• Date: Thu, 7 Feb 2008 06:39:17 -0500 (EST)

```Clear[sols];

sols = i /.
NDSolve[{i'[t] == (1/8.516011) (-i[t] + 0.596120754),
i == 0.219319}, i, {t, 1, 4}][];

sols[3.8]

0.324902

Plot[sols[t], {t, 1, 4}]

Clear[sols];

sols = NDSolve[{i'[t] == (1/8.516011) (-i[t] + 0.596120754),
i == 0.219319}, i, {t, 1, 4}][];

i[3.8] /. sols

0.324902

Plot[i[t] /. sols, {t, 1, 4}]

Bob Hanlon

---- Tara.Ann.Lorenz at gmail.com wrote:
> Hello.
>
> I am having an issue related to the NDSolve function (I am using
> Version 6).  The following example illustrates the problem I am
> having:
>
> Input:
> sols = NDSolve[{i'[t] == (1/8.516011) (-i[t] + 0.596120754),
>    i == 0.219319}, i[t], {t, 1, 4}]
>
> Output:
> {{i[t]->InterpolatingFunction[{{1.,4.}},<>][t]}}
>
> I then would like to solve i[t] for t=3.8
> According to the Mathematica website, I should be able to enter the
>
> i[3.8]/.sols
>
> However, my output is simply i[3.8] and not a numerical value.  What
> else can I try to get a numerical value from the interpolating
> function.
>
> I appreciate any feedback. Thank you
>
>
>

```

• Prev by Date: Re: Conditional Plotting
• Next by Date: Re: Memory and NDSolve
• Previous by thread: Re: Using NDSolve and Finding a specific Value
• Next by thread: Re: Using NDSolve and Finding a specific Value