From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2114 invoked by alias); 17 Mar 2009 11:37:49 -0000 Received: (qmail 2106 invoked by uid 22791); 17 Mar 2009 11:37:49 -0000 X-SWARE-Spam-Status: No, hits=-0.8 required=5.0 tests=AWL,BAYES_20,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mail.network-theory.co.uk (HELO mail.network-theory.co.uk) (66.199.228.187) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 17 Mar 2009 11:37:43 +0000 Date: Tue, 17 Mar 2009 11:37:00 -0000 Message-ID: From: Brian Gough To: Patrick Alken Cc: gsl-discuss@sourceware.org Subject: Re: New extension for Associated Legendre Functions (ALFs) In-Reply-To: <20090316213137.GA4277@hippogriff.homeunix.org> References: <20090316213137.GA4277@hippogriff.homeunix.org> User-Agent: Wanderlust/2.14.0 (Africa) Emacs/22.2 Mule/5.0 (SAKAKI) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII X-Message-Mac: fef985c2c3cdd9a209d02dc859b93524 Mailing-List: contact gsl-discuss-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gsl-discuss-owner@sourceware.org X-SW-Source: 2009-q1/txt/msg00021.txt.bz2 At Mon, 16 Mar 2009 15:31:37 -0600, Patrick Alken wrote: > Most current implementations of associated Legendre functions > (ALFs), including the current GSL version fail due to underflow > above degree and order (L,M) 1900. A 2002 paper by Holmes and > Featherstone shows that with a very simple scaling modification > this limit can be extended to 2700 in double precision. I have > recently needed to compute high degree ALFs so I have implemented > their algorithm and made a new GSL extension if others are interested. Great work! Incidentally, I found a copy of their paper online at http://www.cage.curtin.edu.au/~geogrp/research.html http://www.cage.curtin.edu.au/~will/20760279.pdf -- Brian Gough