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=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.129.122.72 with SMTP id v69mr77992823ywc.40.1470532778408; Sat, 06 Aug 2016 18:19:38 -0700 (PDT) X-Received: by 10.157.49.75 with SMTP id v11mr2055667otd.12.1470532778357; Sat, 06 Aug 2016 18:19:38 -0700 (PDT) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!news.eternal-september.org!feeder.eternal-september.org!usenet.blueworldhosting.com!feeder01.blueworldhosting.com!peer03.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!c52no7390542qte.1!news-out.google.com!d68ni19186ith.0!nntp.google.com!f6no7932363ith.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Sat, 6 Aug 2016 18:19:38 -0700 (PDT) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=50.111.146.161; posting-account=Ies7ywoAAACcdHZMiIRy0M84lcJvfxwg NNTP-Posting-Host: 50.111.146.161 References: <31c22983-150c-4dab-abba-588e15f75914@googlegroups.com> <84d258dc-b60d-4a49-9af4-27dd6f3e5f5f@googlegroups.com> <1703ca9a-2665-4435-9564-4abd8a77ebe9@googlegroups.com> <12ca4276-cd1e-49ae-b5dc-56432e721687@googlegroups.com> <2a3fc931-feb3-4542-a4c9-e43affa5c4f4@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <6cf84976-e561-4935-b674-6c84fbc0531a@googlegroups.com> Subject: Re: New IEEE Language Popularity Ratings From: brbarkstrom@gmail.com Injection-Date: Sun, 07 Aug 2016 01:19:38 +0000 Content-Type: text/plain; charset=UTF-8 X-Received-Bytes: 3377 X-Received-Body-CRC: 1437704217 Xref: news.eternal-september.org comp.lang.ada:31313 Date: 2016-08-06T18:19:38-07:00 List-Id: > > Another example is random number generators. Knuth's Art of Computer > > Programming, Vol. 2, is the basic definitive reference. It includes ten > > tests of a random number generator that anybody needing one should be sure > > have been used. Park and Miller's article many years ago in CACM provides > > code for a portable version of an algorithm that they put through the Knuth > > wringer. In my own work, I've got an Ada library for generating probability > > distributions that includes Park and Miller's algorithm, since it includes > > a test as to whether it's been implemented correctly. I might trust the > > algorithms in MatLab or Mathematica, but this kind of work is not for > > amateur mathematicians. > > These tests, while useful, are probably badly outdated for modern algorithms on > 64-bit processors. More modern tests include TestU01's Crush and Big-Crush test > suites. The Threefry generator is said to be the fastest to pass all the > Big-Crush tests. > > -- > Jeff Carter > "I've seen projects fail miserably for blindly > applying the Agile catechism: we're Agile, we > don't need to stop and think, we just go ahead > and code!" > Bertrand Meyer > 150 The algorithms are mathematical artifacts and they have proofs related to loss of digital information. Whether or not the bits in the hardware are 32 or 64 or 128 bits doesn't matter. Neither does the age. Most mathematical algorithms are essentially ageless. Can we get the Big Crush test suite to identify the specific relations between Knuth's tests and their tests? I'll try to find the time to see if I can use the reference to the RNG in AdaCore. In the mean time, some examination of the floating point standard and rounding and truncation error may be appropriate. Unfortunately, Lawson and Hanson's algorithm doesn't easily translate to Ada because they rely on FORTRAN's (rather opaque) approach to memory management within COMMON blocks for dealing with Pivoting. Bruce B. Bruce B.