Re: BesselJZeros problem/bug?
- To: mathgroup at smc.vnet.net
- Subject: [mg17047] Re: BesselJZeros problem/bug?
- From: Alan Lewis <alanlewis at home.com>
- Date: Wed, 14 Apr 1999 02:11:58 -0400
- Organization: @Home Network
- References: <7es1a3$c7n@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Fails on my machine too. From the large argument asymptotic formula,
try a plot of [Sqrt[2/(Pi x)] Cos[x - Pi/4] vs J0[x]. They are
very close and so the zeros are very close to (n-1/4)Pi, n=1,2,...
So, FindRoot will do it:
roots[nmax_]:=
Table[ x/.FindRoot[BesselJ[0,x]==0,{x,(n-1/4)Pi}],{n,1,nmax}]
Regards,
Alan
Tim Birks wrote:
>
> I have a very simple notebook with just the following two cells:
>
> << NumericalMath`BesselZeros`
> BesselJZeros[0,{3,3}]
>
> Having run the first cell to load the add-on package, running the second
> cell is supposed to return a list containing the value of the 3rd zero
> of the Bessel function J0. However, for me it just never returns at all.
> Is this a bug? and is there a work-around?
>
> There are no problems finding the 1st and 2nd zeros of J0, nor any of
> the zeros of J1, J2, etc. I am running Mathematica 3.0.1.1x on a PC with
> Windows 95.
>
> Any ideas?
>
> T.