From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6629 invoked by alias); 3 Oct 2002 20:21:05 -0000 Mailing-List: contact gsl-discuss-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gsl-discuss-owner@sources.redhat.com Received: (qmail 6604 invoked from network); 3 Oct 2002 20:21:05 -0000 Received: from unknown (HELO blueyonder.co.uk) (195.188.53.96) by sources.redhat.com with SMTP; 3 Oct 2002 20:21:04 -0000 Received: from pcow053o.blueyonder.co.uk ([127.0.0.1]) by blueyonder.co.uk with Microsoft SMTPSVC(5.5.1877.757.75); Thu, 3 Oct 2002 21:21:03 +0100 Received: from localhost (unverified [62.30.73.24]) by pcow053o.blueyonder.co.uk (Content Technologies SMTPRS 4.2.9) with ESMTP id ; Thu, 3 Oct 2002 21:21:03 +0100 Received: by network-theory.co.uk via sendmail from stdin id (Debian Smail3.2.0.102) for floegel@itp.uni-hannover.de; Thu, 3 Oct 2002 21:19:03 +0100 (BST) From: Brian Gough Message-ID: <15772.42551.112082.335903@debian> Date: Thu, 03 Oct 2002 13:21:00 -0000 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Filip Floegel Cc: gsl-discuss@sources.redhat.com Subject: Re: gsl_sf_coupling_3j In-Reply-To: <20021002154552.GA19031@itp.uni-hannover.de> References: <20021002154552.GA19031@itp.uni-hannover.de> X-SW-Source: 2002-q4/txt/msg00010.txt.bz2 Filip Floegel writes: > hello gsl community, > gsl_sf_coupling_3j doesn't work properly for large angular mementa > like j1=j2=j3=40 m1=m2=m3=0 !!! > gsl_sf_coupling_3j_e(80,80,80,0,0,0,&result) > which correspond to j1=j2=j3=40 m1=m2=m3=0 > gives me: > result.val = 0.0625 result.err = 0.172766 > mathematica gives me: > N[ThreeJSymbol[{40,0},{40,0},{40,0}]] = 0.0149685 > my guess is that gamma.c which is used for calculating fractional > numbers probably diverges for large integers. Thanks for the bug report. If you can take a look at the source maybe a different expansion can be used for large values to improve the accuracy? Brian