Re: Problem with combination NDSolve NIntegrate

• To: mathgroup at smc.vnet.net
• Subject: [mg72755] Re: Problem with combination NDSolve NIntegrate
• From: dh <dh at metrohm.ch>
• Date: Thu, 18 Jan 2007 05:22:18 -0500 (EST)
• References: <eol09o\$44r\$1@smc.vnet.net>

```Hi Paul,
Mamthematica tries to evaluate ti[5] and fails. Put ti[5] inside trial[]
and everything works fine:
trial[a_?NumberQ] := ti[5] /. NDSolve[{ti'[t] == ti[t], ti[0] == a}, ti,
{t, 0, 10}][[1]]
Daniel

Paul Schneider wrote:
> I am using version 5.2
>
>
>
> NIntegrate tries to evaluate the integrand symbolically. I try to
>
> circumvent this by using ?NumberQ but without success. Please try the
>
> following toy example:
>
>
>
> trial[a_?NumberQ] :=
>
>      NDSolve[{ti'[t] == ti[t] , ti[0] == a} , ti, {t, 0, 10}];
>
> NIntegrate[ (ti[5] /. trial[a]), {a, 0, 10}]
>
> Plot[ (ti[5] /. trial[a]), {a, 0, 10}]
>
>
>
> NIntegrate does not evaluate to a number and throws a warning, while I
>
> get a perfect plot from Plot.
>
>
>
> Does anybody know what to do?
>
>
>
> Cheers,
>
>
>
> Paul
>
>

```

• Prev by Date: A normalized Series test
• Next by Date: Re: Sorting by date
• Previous by thread: Problem with combination NDSolve NIntegrate
• Next by thread: Re: Problem with combination NDSolve NIntegrate