Re: [Bug-gsl] Bug in dht

[Brian Gough]

At Wed, 22 Dec 2010 15:23:34 +0100, Benno Rem wrote:
> I noticed that, as soon as I try to do a Hankel Transform (nu = 0)
> on a gaussian of the form exp( - pi * r^2 ), transform it back and
> multiply by the factor Jzero0(0,N)^2, that I don't get the exactly
> same function back.  Actually, the function that is returned is
> scaled by a factor 1.00391 with respect to the original function.
> 
> For just one transform it can be considered as just a numerical
> error, but as soon as I try to do some more complicated stuff I get
> strong abbreviations from the real result.
> 
> I'm not sure if this is a bug, or just a misunderstanding of the
> concept, but it would help me a lot if someone could give me an
> idea.

Hello,

I think the transform is only exact for functions that are zero at the
boundaries.  If this does not explain the discrepancy could you send
an example program and output which demonstrates the problem.  Thanks.

-- 
Brian Gough