From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 2AB03138A1A for ; Sat, 1 Nov 2014 20:47:40 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 03BEEE10CB; Sat, 1 Nov 2014 20:47:30 +0000 (UTC) Received: from mail-wi0-f176.google.com (mail-wi0-f176.google.com [209.85.212.176]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id A5CE2E10AB for ; Sat, 1 Nov 2014 20:47:28 +0000 (UTC) Received: by mail-wi0-f176.google.com with SMTP id h11so3713100wiw.15 for ; Sat, 01 Nov 2014 13:47:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=kIZTLEuZwsHKO2O1+nby0/QH/tLEfWMEgUjIXKSVS0U=; b=rWBs/UZ56TFi3IbDB5KcCxpQRaoMrRke4OgB6sk5Zr4G+TLvoocfsXTVEEUNEVAgHW 5LWchW6c+3XLKFjF+n8mwTTX+5KhSnGfQEYtyr3H4Adg7iHNuYzTmfMtiG5dQjK1wHR0 83kJ7c/y3CZmmdSbK7xQGFuHSTuMWQnJlSiM9WBc6ejhPBD+8+oXfych/Y/IhzhUPpK0 ym4uPxLf3idxdfoSoSh2mphJTwsPKQEEozItQp8v+aH7zcunMEf1pj9jv8mX8y6L/Vgj gI8Dhgy4zSkIB/CafjsW9k6dP2wL4i7KRUmZnLFZbfH1cUD4lP8lTTf0SIwYb6fNTGXc vtnQ== X-Received: by 10.180.101.102 with SMTP id ff6mr6001859wib.34.1414874847320; Sat, 01 Nov 2014 13:47:27 -0700 (PDT) Received: from [172.20.0.41] (105-237-231-156.access.mtnbusiness.co.za. [105.237.231.156]) by mx.google.com with ESMTPSA id w13sm16416544wjq.29.2014.11.01.13.47.26 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 01 Nov 2014 13:47:26 -0700 (PDT) Message-ID: <545546D3.3030005@gmail.com> Date: Sat, 01 Nov 2014 22:47:15 +0200 From: Alan McKinnon User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Re: OT Best way to compress files with digits References: <20141031153659.GA13217@solfire> <20141101175934.GB3860@solfire> In-Reply-To: <20141101175934.GB3860@solfire> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Archives-Salt: d5f1c8b9-fa7d-4505-8cf8-a6cb56575660 X-Archives-Hash: 673f836699ec6ec8fab9d146cfdf86f6 On 01/11/2014 19:59, meino.cramer@gmx.de wrote: > James [14-11-01 18:16]: >> gmx.de> writes: >> >> >>> I have a lot of files with digits of PI. The digits >>> are the characters of 0-9. Currently they are ZIPped, >>> which I think is not the best way to do that. >> >> Hello Meino, >> >> It's a bit of effort, but the world's recognized authority >> on algorithms is Don Knuth. [1] He's old now, but his >> pioneering attempt at categorizing most algorithms: >> "The art of computer programming" and his MMIX alogrithm >> implementations (kinda like assembler) are certainly >> part of many first-step research efforts on algorithms >> and their implementations. >> >> It's not a cookbook; more of a scholarly (high_brow) reference, >> just to supplement all the good postings by your peers on gentoo user. >> >> Alan may loan you his copy? >> (ha ha ha)? >> >> >> >> hth, >> James >> >> [1] http://www-cs-faculty.stanford.edu/~uno/ >> > > Hello james, > > Don Knuth ... oh YES! :) > For a long time I am using and prefering TeX over anything else > (ok...for ASCII I use vim... ;). > > And beside his computer wisdom I also like his kind of humor a lot... > for example this one: > https://www.youtube.com/watch?v=eKaI78K_rgA&list=PLUu0XRts4lK6Ri7-xaCNYqTHx7We95Rk8&index=10 > > But my initial question was more targeted to "practical computing" as > to groundshakeing and fundamental research topics. > > More like "what tool to pick?"... > > I did some compression tests myself and currently I have this: >>>From http://piworld.calico.jp/ (http://piworld.calico.jp/estart.html) > I got zipped package of > 1000 million places of PI each (~57MB for one ZIP). > > I unpacked the first package and recompressed it with different > methods of 7zip, gzip and bzip2. For gzip and bzip2 I used the highest > compression mode (-9). When a files name matches /.*ultra.*/, I used > the highest compression mode (-mx=9), else I only set the compression > method and leave the rest untouched (defaults). > > > 119888896 2014-10-31 16:44 pi-0001.txt > 57105419 2014-10-31 16:47 pi-0001.txt.gz > 52632832 2014-10-31 16:48 pi-0001.txt.bz2 > 52045827 2014-10-31 16:54 pi-0001.txt.ppmd.7z > 57110291 2014-10-31 17:23 pi-0001.zip > 51766683 2014-10-31 17:26 pi-0001.txt.lzma.7z > 51668838 2014-10-31 17:34 pi-0001.txt.lzma.ultra.7z > 52862115 2014-10-31 17:36 pi-0001.txt.ppmd.ultra.7z > 51668838 2014-10-31 17:39 pi-0001.txt.ultra.7z > > 7zip's lzma wins here, which is also the default method of 7zip. I set > the ultra mode for this by hand. > >>>From other sites which offer PI for download I know of methods, which > store the ASCII-digits in binary and compresses then. Would be > interesting, whether this creates a more "handy" input from 7zips > point of view... > > Ah! By the way...I was astonished to read, that the digits of PI are > called random on the one hand and on the other hand there is a formula [1] > to calculate a certain digit of PI without calculation of the previous > digits... > Calculated random? Are nature constants the purest form of PRNGs ??? ;) > (Quantum physics is everywhere... ;;)) > > [1]: http://en.wikipedia.org/wiki/Bailey%E2%80%93Borwein%E2%80%93Plouffe_formula The sequence of digits that make up pi are a random sequence - you can analyze the order any way you want and you'll find no inherent pattern. However, any given digit in the sequence is 100% predictable, as you just showed :-) Randomness has got to be the second most mind-boggling thing out there, first being quantumness (that's not a waord, I just made it up. You you should get the meaning OK from context ;-) ) -- Alan McKinnon alan.mckinnon@gmail.com