From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13548 invoked by alias); 24 Aug 2005 15:56:45 -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 13490 invoked by uid 22791); 24 Aug 2005 15:56:36 -0000 Received: from mailwasher.lanl.gov (HELO mailwasher-b.lanl.gov) (192.65.95.54) by sourceware.org (qpsmtpd/0.30-dev) with ESMTP; Wed, 24 Aug 2005 15:56:36 +0000 Received: from nis-mail.lanl.gov (nis-mail.lanl.gov [128.165.4.121]) by mailwasher-b.lanl.gov (8.12.11/8.12.11/(ccn-5)) with ESMTP id j7OFuYKC026135 for ; Wed, 24 Aug 2005 09:56:34 -0600 Received: from yks.lanl.gov (yks.lanl.gov [128.165.112.13]) by nis-mail.lanl.gov (8.12.11/8.12.11/(ccn-5)) with ESMTP id j7OFuWwO017682; Wed, 24 Aug 2005 09:56:32 -0600 Date: Wed, 24 Aug 2005 15:56:00 -0000 From: James Theiler To: Brian Gough cc: gsl-discuss Subject: Re: preparing a new release In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-PMX-Version: 4.7.1.128075 X-SW-Source: 2005-q3/txt/msg00035.txt.bz2 On Wed, 24 Aug 2005, Brian Gough wrote: ] I'm preparing release (it will be 1.7) -- I'd appreciate feedback ] on this test version: ] ] http://www.network-theory.co.uk/download/gsl/gsl-1.6.91.tar.gz ] http://www.network-theory.co.uk/download/gsl/gsl-1.6.91.tar.gz.sig ] ] If there are no problems reported then I will release it. Thanks. ] ] configure; make; make check all worked without a problem on RH Enterprise Linux 3 saw one typo in your list of changes: ** Fixed the branch selection in gsl_sf_gamma_inc_Q_e to prevent caused inaccurate results for large a,x where x~=~a. "prevent caused" -> "prevent" === By the way, I think there is an error in the documentation (code looks okay) regarding Gaussian Tail Distribution, section 19.3. Formula for p(x) should have an extra factor of 1/sqrt(2*pi*sigma^2). Also, the figure for p(x) is incorrectly normalized -- you can tell it is incorrect because the area under the curve should be one, but is obviously much less than that. It looks like that curve was generated with a p(x) that *did* have the 1/sqrt(2*pi*sigma^2) but did *not* have the 1/N(a;sigma) -- that is, it looks like the tail of the gaussian in the Figure before it in section 19.2, without any renormalization. (An example of a correct picture of a tail distribution is in 19.10, for the Rayleigh tail distribution.) === More on documentation, Chapter 7 introduces the Pochhammer symbol (a)_x with the function gsl_sf_poch. Four functions later, in gsl_sf_pochrel, a new notation is introduced (a,x). If you want to include (a,x) as an alternative notation, that could be done with the gsl_sf_poch function; simpler would be to drop it entirely, and say for gsl_sf_pochrel, ie: These routines compute the relative Pochhammer symbol @math{((a,x) - 1)/x} where @math{(a,x) = (a)_x := \Gamma(a + x)/\Gamma(a)}. -> These routines compute the relative Pochhammer symbol @math{((a)_x - 1)/x} where @math{(a)_x := \Gamma(a + x)/\Gamma(a)}. === The documentation in section 7.19 for gsl_sf_beta_inc does not define B_x(a,b), which is B_x(a,b) = \int_0^x t^{a-1} (1-t)^{b-1} dt === On a more general note, I'd recommend changing the title of Section 7.19 from "Gamma Function" to "Gamma and Beta Functions". And this is more for the ToDo list, but we could use the introduction to this section to talk about factorials, combinations, binomial coefficients, use of tables for integer values, etc. As a quickfix, we might just remark on the identity \Gamma(n)=(n-1)! for integer n>0. I don't think this is in that section at all. regards, jt -- James Theiler Space and Remote Sensing Sciences MS-B244, ISR-2, LANL Los Alamos National Laboratory Los Alamos, NM 87545 http://nis-www.lanl.gov/~jt