From -2487548043688312654 X-Google-Thread: f78e5,4ba9dcb1ae436e16 X-Google-Attributes: gidf78e5,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news2.google.com!proxad.net!proxad.net!194.159.246.34.MISMATCH!peer-uk.news.demon.net!kibo.news.demon.net!news.demon.co.uk!demon!stump.algebra.com!devnull From: nagle@animats.com (John Nagle) Newsgroups: comp.std.c++ Subject: Re: Pi, Euler Number, and perhaps other 'natural' constants? Date: Wed, 28 Jul 2004 04:38:21 GMT Organization: SBC http://yahoo.sbc.com Lines: 29 Sender: mail2news@demon.net Approved: fjh@cs.mu.oz.au (Fergus Henderson , moderator of comp.std.c++) Message-ID: References: <5cydnSisJNo4yJncRVn-sQ@speakeasy.net> NNTP-Posting-Host: news.news.demon.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Trace: news.demon.co.uk 1090989506 3899 158.152.254.254 (28 Jul 2004 04:38:26 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Wed, 28 Jul 2004 04:38:26 +0000 (UTC) X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) X-User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.6) Gecko/20040113 X-Spam-Checker-Version: SpamAssassin 2.60-mulga_r1 (1.212-2003-09-23-exp) on mulga.cs.mu.OZ.AU X-Spam-Status: No, hits=-3.2 required=5.2 tests=AWL,BAYES_00 autolearn=ham version=2.60-mulga_r1 X-Accept-Language: en-us, en, ja X-UserInfo1: FKPO@SBE[JTIRVX[]BCD^VX@WB]^PCPDLXUNNHPIMASJETAANVW[AKWZE\]^XQWIGNE_[EBL@^_\^JOCQ^RSNVLGTFTKHTXHHP[NB\_C@\SD@EP_[KCXX__AGDDEKGFNB\ZOKLRNCY_CGG[RHT_UN@C_BSY\G__IJIX_PLSA[CCFAULEY\FL\VLGANTQQ]FN X-Path: comp-std-cpp-robomod!not-for-mail X-Received: (from fjh@localhost) by mulga.cs.mu.OZ.AU (8.12.10+Sun/8.12.9/Submit) id i6S4cLO6016488; Wed, 28 Jul 2004 14:38:21 +1000 (EST) X-NNTP-Posting-Date: Tue, 27 Jul 2004 12:31:14 EDT X-Spam-Level: X-Delivered-To: std-c++@ucar.edu X-Spamscanner: mailbox3.ucsd.edu (v1.4 May 20 2004 13:55:33, 0.0/5.0 2.63) X-Authentication-Warning: mulga.cs.mu.OZ.AU: fjh set sender to devnull@stump.algebra.com using -f X-Newsgroups: comp.std.c++ X-MailScanner: PASSED (v1.2.8 94403 i6RGVGDx024780 mailbox3.ucsd.edu) Xref: g2news1.google.com comp.std.c++:1469 Daniel Pfeffer wrote: > "Steven T. Hatton" wrote in message > news:5cydnSisJNo4yJncRVn-sQ@speakeasy.net... > For serious numerical work, the required machine representation > of PI must be determined for each floating-point > implementation. That's a bit much. It's not like the value of "pi" is a matter of either opinion or measurement. We should have "std::pi" as a double, accurate to the last bit of a double, even if it has to be calculated offline and stored as a hex float. This is worth doing, because it's a huge pain to do that and it only needs to be done once. I'd provide "pi" and "e", but stop there. For one thing, the trig functions themselves need those constants, so they're already in the library somewhere. John Nagle Animats --- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://www.jamesd.demon.co.uk/csc/faq.html ]