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Re: complex number in struct form in C

From BartC <bc@freeuk.com>
Newsgroups comp.lang.c
Subject Re: complex number in struct form in C
References (9 earlier) <m7r9bb$lgf$1@speranza.aioe.org> <20141229112747.367@kylheku.com> <m7sf31$ojc$1@speranza.aioe.org> <L5kow.322775$Ea7.266278@fx16.am4> <m7t4u3$v05$1@speranza.aioe.org>
Message-ID <Isvow.940268$u67.647565@fx08.am4> (permalink)
Organization virginmedia.com
Date 2014-12-30 10:51 +0000

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On 30/12/2014 03:07, glen herrmannsfeldt wrote:
> BartC <bc@freeuk.com> wrote:

>> (I'm done some typesetting (of technical manuals with hundreds of pages)
>> using a graphical program that exclusively used floating point. The
>> output was sent to a Postscript printer for it to do the hard job of
>> getting quality output. Postscript seems to use floating point as its
>> primary data type (I don't know what it does internally).
>
> Did you ever try to do a 90 or 180 degree rotation in PostScript?
> Systems I used to know wouldn't do it right.  (That is, sin(180)
> and cos(90) aren't zero.

What's so magical about fixed point then in that it manages to get 
sin(180) and cos(90) exactly right? That is, sin(pi) and cos(pi/2) when 
using radians, since usually working with degrees involves conversion to 
radians internally.

But if degrees /are/ being used, then it is trivial to first check for 
these exact quarter angles. Even if they are expressed as 90.0 and 
180.0. (In fact, I have an old graphics program where if you rotate 
bitmap objects, it can only display them when rotated by exactly 0, 90, 
180, 270 etc degrees, but not 89.9 degrees. All expressed as floating 
point numbers.)

>> Maybe, on a different system, there might have been the odd paragraph
>> where a line break occurs before or after a particular word. But
>> repeatability was not an issue. This is just a counter-example to your
>> claim that you should never use floating point for typesetting.)
>
> I was just recalling some of Knuth's examples. You can argue it
> out with him if you would like.

This is the chap who used a made-up assembly language called MIX in his 
books (based around 6-bit word lengths or something)? This is instead of 
using a made-up high-level language (ie. pseudo-code) that people could 
understand.

Enough said...


-- 
Bartc


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Thread

complex number in struct form in C Dexterr <dejangru@gmail.com> - 2014-12-21 07:20 -0800
  Re: complex number in struct form in C James Kuyper <jameskuyper@verizon.net> - 2014-12-21 11:30 -0500
    Re: complex number in struct form in C Dexterr <dejangru@gmail.com> - 2014-12-21 08:35 -0800
      Re: complex number in struct form in C "Osmium" <r124c4u102@comcast.net> - 2014-12-21 10:54 -0600
        Re: complex number in struct form in C James Kuyper <jameskuyper@verizon.net> - 2014-12-21 12:00 -0500
          Re: complex number in struct form in C "Osmium" <r124c4u102@comcast.net> - 2014-12-21 11:08 -0600
            Re: complex number in struct form in C Barry Schwarz <schwarzb@dqel.com> - 2014-12-21 10:12 -0800
              Re: complex number in struct form in C "Osmium" <r124c4u102@comcast.net> - 2014-12-21 13:22 -0600
                Re: complex number in struct form in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-12-21 22:21 +0000
              Re: complex number in struct form in C asetofsymbols@gmail.com - 2014-12-26 11:34 -0800
                Re: complex number in struct form in C "Osmium" <r124c4u102@comcast.net> - 2014-12-26 14:10 -0600
                Re: complex number in struct form in C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-28 07:04 +0000
                Re: complex number in struct form in C BartC <bc@freeuk.com> - 2014-12-28 13:14 +0000
                Re: complex number in struct form in C Robert Wessel <robertwessel2@yahoo.com> - 2014-12-28 10:45 -0600
                Re: complex number in struct form in C Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-12-28 08:56 -0800
                Re: complex number in struct form in C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-29 10:10 +0000
                Re: complex number in struct form in C Kaz Kylheku <kaz@kylheku.com> - 2014-12-29 19:40 +0000
                Re: complex number in struct form in C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-29 20:54 +0000
                Re: complex number in struct form in C BartC <bc@freeuk.com> - 2014-12-29 21:55 +0000
                Re: complex number in struct form in C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-30 03:07 +0000
                Re: complex number in struct form in C BartC <bc@freeuk.com> - 2014-12-30 10:51 +0000
                Re: complex number in struct form in C Rosario193 <Rosario@invalid.invalid> - 2014-12-30 12:15 +0100
                Re: complex number in struct form in C Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-12-30 03:31 -0800
                Re: complex number in struct form in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-12-30 12:17 +0000
                Re: complex number in struct form in C BartC <bc@freeuk.com> - 2014-12-30 13:18 +0000
                Re: complex number in struct form in C Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-12-30 05:28 -0800
                Re: complex number in struct form in C BartC <bc@freeuk.com> - 2014-12-30 13:53 +0000
                Re: complex number in struct form in C "Osmium" <r124c4u102@comcast.net> - 2014-12-30 08:53 -0600
                Re: complex number in struct form in C "Chris M. Thomasson" <no@spam.invalid> - 2014-12-30 20:05 -0800
                Re: complex number in struct form in C Jeff Higgins <jeff@invalid.invalid> - 2014-12-30 17:40 -0500
                Re: complex number in struct form in C Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-24 08:58 -0700
                Re: complex number in struct form in C Les Cargill <lcargill99@comcast.com> - 2015-03-24 19:41 -0500
                Re: complex number in struct form in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-12-30 14:59 +0000
                Re: complex number in struct form in C David Thompson <dave.thompson2@verizon.net> - 2015-01-12 15:33 -0500
                Re: complex number in struct form in C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-01-12 22:51 +0000
                Re: complex number in struct form in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-01-12 23:34 +0000
                Re: complex number in struct form in C James Kuyper <jameskuyper@verizon.net> - 2014-12-26 15:25 -0500
                Re: complex number in struct form in C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-28 07:17 +0000
                Re: complex number in struct form in C BartC <bc@freeuk.com> - 2014-12-26 20:49 +0000
                Re: complex number in struct form in C asetofsymbols@gmail.com - 2014-12-27 00:22 -0800
                Re: complex number in struct form in C "Osmium" <r124c4u102@comcast.net> - 2014-12-27 08:25 -0600
                Re: complex number in struct form in C Geoff <geoff@invalid.invalid> - 2014-12-27 10:20 -0800
                Re: complex number in struct form in C "Osmium" <r124c4u102@comcast.net> - 2014-12-27 13:21 -0600
                Re: complex number in struct form in C Geoff <geoff@invalid.invalid> - 2014-12-27 13:11 -0800
                Re: complex number in struct form in C "Osmium" <r124c4u102@comcast.net> - 2014-12-27 15:36 -0600
                Re: complex number in struct form in C Geoff <geoff@invalid.invalid> - 2014-12-27 14:54 -0800
                Re: complex number in struct form in C Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-12-27 15:45 -0800
                Re: complex number in struct form in C Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-12-27 13:40 -0800
                Re: complex number in struct form in C James Kuyper <jameskuyper@verizon.net> - 2014-12-28 06:50 -0500
                Re: complex number in struct form in C Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-12-28 04:25 -0800
                Re: complex number in struct form in C James Kuyper <jameskuyper@verizon.net> - 2014-12-28 06:44 -0500
                Re: complex number in struct form in C Richard Damon <Richard@Damon-Family.org> - 2014-12-28 08:33 -0500
                Re: complex number in struct form in C James Kuyper <jameskuyper@verizon.net> - 2014-12-27 11:46 -0500
                Re: complex number in struct form in C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-28 07:28 +0000
                Re: complex number in struct form in C Kaz Kylheku <kaz@kylheku.com> - 2014-12-27 17:23 +0000
            Re: complex number in struct form in C James Kuyper <jameskuyper@verizon.net> - 2014-12-21 14:37 -0500
          Re: complex number in struct form in C Keith Thompson <kst-u@mib.org> - 2014-12-21 12:37 -0800
          Re: complex number in struct form in C glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-22 00:54 +0000
      Re: complex number in struct form in C James Kuyper <jameskuyper@verizon.net> - 2014-12-21 11:54 -0500
      Re: complex number in struct form in C Vincenzo Mercuri <nomail@yahoo.it> - 2014-12-21 18:07 +0100
        Re: complex number in struct form in C Dexterr <dejangru@gmail.com> - 2014-12-21 10:37 -0800
          Re: complex number in struct form in C "Chris M. Thomasson" <no@spam.invalid> - 2014-12-21 10:55 -0800
          Re: complex number in struct form in C raltbos@xs4all.nl (Richard Bos) - 2014-12-22 12:15 +0000
            Re: complex number in struct form in C Dexterr <dejangru@gmail.com> - 2014-12-22 05:51 -0800
              Re: complex number in struct form in C BartC <bc@freeuk.com> - 2014-12-22 14:01 +0000
                Re: complex number in struct form in C Keith Thompson <kst-u@mib.org> - 2014-12-22 08:02 -0800
            Re: complex number in struct form in C Keith Thompson <kst-u@mib.org> - 2014-12-22 08:03 -0800
    Re: complex number in struct form in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-12-21 22:27 +0000
  Re: complex number in struct form in C "Chris M. Thomasson" <no@spam.invalid> - 2014-12-21 10:51 -0800
    Re: complex number in struct form in C Dexterr <dejangru@gmail.com> - 2014-12-21 11:14 -0800
  Re: complex number in struct form in C Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-12-21 17:17 -0800

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