From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.50) id 1EVWfL-0001o0-1v for garchives@archives.gentoo.org; Fri, 28 Oct 2005 16:01:15 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.13.5/8.13.5) with SMTP id j9SG09xV011257; Fri, 28 Oct 2005 16:00:09 GMT Received: from authusersmtp.mail.cornell.edu (granite1.mail.cornell.edu [128.253.83.141]) by robin.gentoo.org (8.13.5/8.13.5) with ESMTP id j9SG07JE028038 for ; Fri, 28 Oct 2005 16:00:08 GMT Received: from leibniz.ether (user-10mt4mi.cable.mindspring.com [65.110.146.210]) (authenticated bits=0) by authusersmtp.mail.cornell.edu (8.13.1/8.12.10) with ESMTP id j9SG06WR008001 (version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=NOT) for ; Fri, 28 Oct 2005 12:00:06 -0400 (EDT) From: Darren Dale To: gentoo-science@lists.gentoo.org Subject: Re: [gentoo-science] question about signbit Date: Fri, 28 Oct 2005 12:00:05 -0400 User-Agent: KMail/1.8.3 References: <200510221416.03348.dd55@cornell.edu> <200510270852.35524.dd55@cornell.edu> <43624657.4060301@gmx.net> In-Reply-To: <43624657.4060301@gmx.net> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-science@gentoo.org Reply-to: gentoo-science@lists.gentoo.org MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200510281200.05694.dd55@cornell.edu> X-Archives-Salt: e7385326-0957-4f74-9540-12bd816fc299 X-Archives-Hash: 46a4ed4b7e5cd9c3528674caaba1c666 On Friday 28 October 2005 11:40 am, Marco Matthies wrote: > Darren Dale wrote: > > signbit(-1): -2147483648 > > isnan(0.0/0): 1 > > isinf(1.0/0): 1 > > As other people have already noted, signbit from math.h is behaving as > it should. > > > Do you know why signbit doesn't yield 1? I wonder if this might be the > > source of the problem in Scipy. > > I actually had a look at scipy today, and it uses its own signbit > routine -- so looking at what signbit from math.h does is totally > irrelevant. The scipy signbit implementation does say it returns 0 or 1. Actually, SciPy's signbit is only used if math.h does not supply it. On my system, the math.h version of signbit is used. I talked with the lead scipy developer this morning, and based on the fact that signbit was returning a nonzero result rather than 1, he made a modification to scipy's code and we got the problem solved. Thank you everyone for your help. All of Scipy's tests are now successful on my arch, I think they will have a test release coming in the not-too-distant future. Darren -- gentoo-science@gentoo.org mailing list