Re: Compressing js file?

From	Denis McMahon <denismfmcmahon@gmail.com>
Newsgroups	comp.lang.javascript
Subject	Re: Compressing js file?
Date	2014-01-01 16:25 +0000
Organization	A noiseless patient Spider
Message-ID	<la1fhv$94r$1@dont-email.me> (permalink)
References	(5 earlier) <l9n6np$kh3$1@speranza.aioe.org> <XnsA2A4D5AEECAAEeejj99@194.109.133.133> <l9qms1$3oc$1@speranza.aioe.org> <31a96a3f-686c-41d8-ba1e-4cd4f36ac84d@googlegroups.com> <la0hbp$tuo$1@speranza.aioe.org>

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On Wed, 01 Jan 2014 02:50:22 -0500, emf wrote:

> I created an ephemeris.b36.csv file, with the planetary positions in
> base 36 minutes, 3 characters each - 4 with the c or HRt; it is 482 KB
> while the ephemeris.csv was 696 KB, where each position was 5 (/ 6). The
> difference is significant but for practical purposes not too impressive:
> both are a little large.
> 
> Then I gzipped it too: to my surprise its size was 153 KB, exactly the
> same as the gz of the ephemeris.csv.

That's not a great surprise if you understand how file compression 
algorithms work. I only have a very loose understanding of such things, 
but basically they use various combinations of different compression 
techniques, one of which is to remove redundant bits.

For example, if you are compressing n digit numbers as base 10 ascii 
strings, you are generally using 8n bits of data to express a value in 
something of the order of 3.5n bits.

By converting the numeric data to base 36, you have in effect performed a 
form of tokenization which would otherwise be done by the compression 
algorithm.

-- 
Denis McMahon, denismfmcmahon@gmail.com

Thread

Compressing js file? emf <emfril@gmail.com> - 2013-12-23 14:31 -0500
  Re: Compressing js file? Joao Rodrigues <groups_jr-1@yahoo.com.br> - 2013-12-23 22:08 -0200
  Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2013-12-23 16:40 -0800
    Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-24 13:23 -0500
    Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-26 21:56 -0500
      Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-12-27 09:52 +0100
        Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-27 08:18 -0500
          Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-12-27 16:59 +0100
            Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-27 15:32 -0500
              Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-28 15:12 -0500
                Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-01 02:17 -0500
        Re: Compressing js file? Dr J R Stockton <reply1300@merlyn.demon.co.uk.invalid> - 2013-12-28 20:20 +0000
      XHR with timing issues (was: Compressing js file?) Christoph Michael Becker <cmbecker69@arcor.de> - 2013-12-27 22:33 +0100
        Re: XHR with timing issues (was: Compressing js file?) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-12-27 23:26 +0100
          Re: XHR with timing issues Christoph Michael Becker <cmbecker69@arcor.de> - 2013-12-28 12:08 +0100
            Re: XHR with timing issues emf <emfril@gmail.com> - 2013-12-28 09:04 -0500
  Re: Compressing js file? wolfgang zeidler <invalid@invalid.invalid> - 2013-12-27 22:33 +0100
    Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-28 00:16 -0500
      Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-12-28 11:13 +0100
        Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-28 11:26 -0500
          Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-28 13:53 -0500
            Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-12-28 21:00 +0100
              Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-29 21:47 -0500
                Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2013-12-31 14:05 -0800
                Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-01 02:50 -0500
                Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-01 01:16 -0800
                Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-01 08:13 -0500
                Re: Compressing js file? Tim Streater <timstreater@greenbee.net> - 2014-01-01 14:17 +0000
                Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-01 15:31 -0800
                Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-01 18:38 -0500
                Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-01 15:45 -0800
                Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-02 11:43 -0500
                Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-02 09:34 -0800
                OT: Compressing js file? Christoph Michael Becker <cmbecker69@arcor.de> - 2014-01-02 19:52 +0100
                Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-03 07:19 -0500
                Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-03 07:31 -0500
                Re: Compressing js file? Tim Streater <timstreater@greenbee.net> - 2014-01-02 09:14 +0000
                Re: Compressing js file? Denis McMahon <denismfmcmahon@gmail.com> - 2014-01-01 16:25 +0000
                Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-01 21:36 +0100
          Re: Compressing js file? wolfgang zeidler <invalid@invalid.invalid> - 2013-12-29 20:06 +0100
            Re: Compressing js file? wolfgang zeidler <invalid@invalid.invalid> - 2013-12-29 20:27 +0100
        Re: Compressing js file? Dr J R Stockton <reply1300@merlyn.demon.co.uk.invalid> - 2013-12-29 18:02 +0000
          Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-12-30 18:17 +0100
            Re: Compressing js file? John Harris <niam@jghnorth.org.uk.invalid> - 2013-12-31 10:52 +0000
            Re: Compressing js file? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-12-31 13:38 +0000
              Re: Compressing js file? John Harris <niam@jghnorth.org.uk.invalid> - 2013-12-31 15:02 +0000
                Re: Compressing js file? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-01-01 16:42 +0000
                Re: Compressing js file? Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-01-01 21:32 +0000
            Re: Compressing js file? Dr J R Stockton <reply1300@merlyn.demon.co.uk.invalid> - 2013-12-31 21:44 +0000

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