Bessel_I problem



I was hoping for bessel_i(n,x) in terms of some other built in Maxima functions for negative n.  Mathematica can do it.

Rich




 ------------Original Message------------
From: David Scott <d.scott at auckland.ac.nz>
To: rrogers at plaidheron.com
Cc: "Richard Hennessy" <rvh2007 at comcast.net>, "Maxima List" <maxima at math.utexas.edu>
Date: Sun, May-4-2008 7:34 PM
Subject: Re: [Maxima] Bessel_I problem

On Sun, 4 May 2008, Raymond E. Rogers wrote:

> Richard Hennessy wrote:
>> Maxima cannot evaluate bessel_i(-1/6,1).  It seems like it does not evaluate for any negative first argument.  Is there a work around for this?
>>
>> Rich
>>
>>
>>
>>
> Are you willing to use the recurrence from A&S?
> I have the book open or I can send a copy of the page.
>
> RayR
> _______________________________________________


For what it is worth, the R implementation of Bessel functions (which 
comes from netlib), claims to use 9.1.2 and 9.6.2 from A&S and gives:

> besselI(1,-1/6)
[1] 1.313664

(Index/order and argument are in the reverse order in the R 
implementation)


David Scott

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