public inbox for gsl-discuss@sourceware.org
 help / color / mirror / Atom feed
From: Brian Gough <bjg@gnu.org>
To: jhu_80@yahoo.com
Cc: gsl-discuss@sourceware.org
Subject: Re: Library for FT alpha-Stable ch.f. (fwd)
Date: Thu, 03 Jul 2008 11:47:00 -0000	[thread overview]
Message-ID: <87fxqrkx5b.wl%bjg@network-theory.co.uk> (raw)
In-Reply-To: <Pine.LNX.4.44.0807021148190.17938-100000@yks.lanl.gov>

At Wed, 2 Jul 2008 11:55:32 -0600 (MDT),
James Theiler wrote:
> I reading thru the source code for the Levy library written for GNU.  The statistical model that we are studying is like alpha-stable as only the ch.f. is in closed form.  It will be presented this autumn in Melbourne, AU.  
> 
> Have you already considered using Fast Fourier transform for the Fourier transform integral?  
> p(x) dx = (1/(2 pi)) \int dt exp(- it x - |c t|^alpha)
> If so, was the Frequency Sampling Technique applied in FFT/IFFT adaptive to the alpha parameter for faster computation?  Or was there a bound placed on alpha to imply out Nyquist frequency for your IFFT/FFT?  I look forward to your input.  Thank you for your time and consideration.

The FFT method was too complicated for our needs as a general purpose
library so I did not look at it.  We only provide cumulative
distribution functions when they are available in closed form.

-- 
Brian Gough

      reply	other threads:[~2008-07-03 11:47 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-02 17:56 James Theiler
2008-07-03 11:47 ` Brian Gough [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87fxqrkx5b.wl%bjg@network-theory.co.uk \
    --to=bjg@gnu.org \
    --cc=gsl-discuss@sourceware.org \
    --cc=jhu_80@yahoo.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).