From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,6d7a86bff9319841 X-Google-Attributes: gid103376,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news3.google.com!feeder1-2.proxad.net!proxad.net!feeder2-2.proxad.net!newsfeed.arcor.de!newsspool2.arcor-online.net!news.arcor.de.POSTED!not-for-mail From: "Dmitry A. Kazakov" Subject: Re: Where I find Bessel function for Ada ? Newsgroups: comp.lang.ada User-Agent: 40tude_Dialog/2.0.15.1 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Reply-To: mailbox@dmitry-kazakov.de Organization: cbb software GmbH References: Date: Wed, 26 Nov 2008 13:57:09 +0100 Message-ID: NNTP-Posting-Date: 26 Nov 2008 13:57:09 CET NNTP-Posting-Host: ee1d8c62.newsspool3.arcor-online.net X-Trace: DXC=hN0ajB61hWI[6=1B@oB@@@McF=Q^Z^V3H4Fo<]lROoRA^YC2XCjHcbI_>;:69m`jGIDNcfSJ;bb[EFCTGGVUmh?DLK[5LiR>kgBS[=Ja]M?2^J X-Complaints-To: usenet-abuse@arcor.de Xref: g2news2.google.com comp.lang.ada:3779 Date: 2008-11-26T13:57:09+01:00 List-Id: On Wed, 26 Nov 2008 03:05:23 -0800 (PST), gautier_niouzes@hotmail.com wrote: >> I want to use the modified Bessel function of order 0 in my Ada >> program. >> >> Where I find it ? > > It is in the Numerical Recipes in Pascal, chapter 6.4, pp 191. > All you need to pick the right Pascal source, like bessj0.pas > and put it through th P2Ada translator: http://p2ada.sf.net/ > The NR sources are freely available on the Internet. Well, if there is no Ada code, then I would also consider to implement it from scrap. There is an excellent book "Mathematical Functions and Their Approximations" by Yudell L. Luke: http://www.amazon.com/Mathematical-Functions-Their-Approximations-Yudell/dp/0124599508 If I correctly remember it contains coefficients of Chebyshev polynomial approximations for various Bessel functions with a huge number of decimal places. Chebyshev polynomes are fairly simple and efficient to sum. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de