Re: NIntegrate and Plot
- To: mathgroup at smc.vnet.net
- Subject: [mg95779] Re: NIntegrate and Plot
- From: dimitris <dimmechan at yahoo.com>
- Date: Tue, 27 Jan 2009 06:57:47 -0500 (EST)
- References: <glethi$4pp$1@smc.vnet.net> <glk80f$o7v$1@smc.vnet.net>
On 26 =C9=E1=ED, 13:49, dh <d... at metrohm.com> wrote:
> Hi Dimitris,
>
> integrate your function before plotting it:
>
> Integrate[fun[r, t], {t, 0, Infinity}, Assumptions -> {r >= 0}]
>
> hope this helps, Daniel
>
> dimitris wrote:
> > Hello.
>
> > I have the following function
>
> > fun[r_, t_] := -(((-3 + 4*t^2 + 8*t^4 - 8*t^3*Sqrt[1 + t^2])*
> > BesselJ[1, r*t])/(3 + 14*t^2 + 24*t^4 + 16*t^6 -
> > 16*t^3*Sqrt[1 + t^2] - 16*t^5*Sqrt[1 + t^2]))
>
> > How can I achieve better performance in the following task
>
> > Plot[NIntegrate[fun[r, t], {t, 0, Infinity}], {r, 0, 3}]
>
> > Thank you very much.
Hi Daniel and thanks for your response.
For what reason to use Integrate since Mathematica cannot evaluate
analytically
the integral?
Dimitris