Re: Floating Point : To Stack or Not To Stack

From	Paul Rubin <no.email@nospam.invalid>
Newsgroups	comp.lang.forth
Subject	Re: Floating Point : To Stack or Not To Stack
Date	2013-10-19 02:58 -0700
Organization	Nightsong/Fort GNOX
Message-ID	<7xhacd4m65.fsf@ruckus.brouhaha.com> (permalink)
References	<l3hjj8$nt6$1@dont-email.me> <l3q8sc$tm$1@speranza.aioe.org> <-OmdnYxW5ugYfP3PnZ2dnUVZ_oednZ2d@supernews.com> <l3smg6$l0e$1@speranza.aioe.org> <Wo-dnUbV6o5YZPzPnZ2dnUVZ_s-dnZ2d@supernews.com>

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"Elizabeth D. Rather" <erather@forth.com> writes:
>  If you are taking data with, say, a 12-bit A/D, you will never have
> more resolution on that data, and a floating point calculation with
> 60-bit values will tempt you to forget that fact. Moreover, roundoff
> errors can eat into the accuracy you have.

The idea of using high-precision intermediate results is to AVOID having
roundoff error clobber what little info you start with.  The x87
historically used 80 bits for all the internal calculations and was
considered numerically superior to the stuff being used now.  See
http://cs.berkeley.edu/~wkahan for endless rants on this topic and
related ones.

Thread

Floating Point : To Stack or Not To Stack rickman <gnuarm@gmail.com> - 2013-10-14 16:18 -0400
  Re: Floating Point : To Stack or Not To Stack "Elizabeth D. Rather" <erather@forth.com> - 2013-10-14 10:34 -1000
    Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-14 15:41 -0500
    Re: Floating Point : To Stack or Not To Stack Paul Rubin <no.email@nospam.invalid> - 2013-10-14 20:32 -0700
      Re: Floating Point : To Stack or Not To Stack rickman <gnuarm@gmail.com> - 2013-10-15 17:14 -0400
    Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-15 16:22 +0000
  Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-14 15:42 -0500
    Re: Floating Point : To Stack or Not To Stack Hans Bezemer <the.beez.speaks@gmail.com> - 2013-10-16 11:16 +0200
  Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-15 16:09 +0000
  Re: Floating Point : To Stack or Not To Stack krishna.myneni@ccreweb.org - 2013-10-15 18:51 -0700
    Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-16 03:47 -0500
    Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-16 12:27 +0000
      Re: Floating Point : To Stack or Not To Stack rickman <gnuarm@gmail.com> - 2013-10-25 14:20 -0400
        Re: Floating Point : To Stack or Not To Stack Paul Rubin <no.email@nospam.invalid> - 2013-10-25 12:08 -0700
          Re: Floating Point : To Stack or Not To Stack rickman <gnuarm@gmail.com> - 2013-10-26 02:34 -0400
            Re: Floating Point : To Stack or Not To Stack Paul Rubin <no.email@nospam.invalid> - 2013-10-26 00:13 -0700
              Re: Floating Point : To Stack or Not To Stack "Elizabeth D. Rather" <erather@forth.com> - 2013-10-25 21:49 -1000
                Re: Floating Point : To Stack or Not To Stack Paul Rubin <no.email@nospam.invalid> - 2013-10-26 01:26 -0700
                Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-26 05:45 -0500
                Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-26 13:48 +0000
                Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-26 14:28 -0500
                Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-27 12:41 +0000
                Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-27 08:31 -0500
                ?DUP (was: Floating Point : To Stack or Not To Stack) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-28 15:19 +0000
                Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-28 13:54 -0500
                Re: ?DUP "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-10-28 16:30 -0400
                Re: ?DUP "Elizabeth D. Rather" <erather@forth.com> - 2013-10-28 11:11 -1000
                Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-29 11:51 +0000
                Re: ?DUP Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-29 16:48 +0100
                Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-29 16:10 +0000
                Re: ?DUP albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-29 16:24 +0000
                Re: ?DUP Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-29 20:00 +0100
                Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-30 07:44 +0000
                Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-29 16:29 -0500
                Re: ?DUP "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-10-29 18:58 -0400
                Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-30 03:15 -0500
                Re: ?DUP albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-30 01:14 +0000
                Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-30 08:22 +0000
                Re: ?DUP "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-10-30 08:03 -0400
                Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-30 12:24 +0000
                Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-30 12:44 -0500
                Re: ?DUP "Alex McDonald" <blog@rivadpm.com> - 2013-10-30 22:43 +0000
                Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-31 12:09 +0000
                Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-31 12:23 -0500
                Re: ?DUP (was: Floating Point : To Stack or Not To Stack) "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-10-28 16:30 -0400
                Re: ?DUP "Elizabeth D. Rather" <erather@forth.com> - 2013-10-28 11:16 -1000
                Re: ?DUP Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-29 01:58 +0100
                Re: ?DUP Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2013-10-28 18:41 -0700
                Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-29 04:37 -0500
                Re: ?DUP m.a.m.hendrix@tue.nl - 2013-10-29 04:27 -0700
                Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-29 12:51 +0000
              Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-26 09:45 +0000
                Re: Floating Point : To Stack or Not To Stack albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-26 11:30 +0000
                Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-26 08:05 -0500
                Re: Floating Point : To Stack or Not To Stack mhx@iae.nl - 2013-10-26 06:09 -0700
                Re: Floating Point : To Stack or Not To Stack "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-10-27 03:01 -0400
                Re: Floating Point : To Stack or Not To Stack "Elizabeth D. Rather" <erather@forth.com> - 2013-10-26 22:23 -1000
            Re: Floating Point : To Stack or Not To Stack albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-26 09:39 +0000
              Re: Floating Point : To Stack or Not To Stack albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-26 09:44 +0000
  Re: Floating Point : To Stack or Not To Stack "Ed" <invalid@invalid.com> - 2013-10-18 14:09 +1000
    Re: Floating Point : To Stack or Not To Stack "Elizabeth D. Rather" <erather@forth.com> - 2013-10-17 21:21 -1000
      Re: Floating Point : To Stack or Not To Stack "Ed" <invalid@invalid.com> - 2013-10-19 12:14 +1000
        Re: Floating Point : To Stack or Not To Stack "Elizabeth D. Rather" <erather@forth.com> - 2013-10-18 17:17 -1000
          Re: Floating Point : To Stack or Not To Stack Paul Rubin <no.email@nospam.invalid> - 2013-10-19 02:58 -0700
          Re: Floating Point : To Stack or Not To Stack "Ed" <invalid@invalid.com> - 2013-10-27 22:33 +1100
            Re: Floating Point : To Stack or Not To Stack mhx@iae.nl - 2013-10-27 06:21 -0700
              Re: Floating Point : To Stack or Not To Stack "Ed" <invalid@invalid.com> - 2013-10-29 22:40 +1100
            Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-27 08:23 -0500
  Re: Floating Point : To Stack or Not To Stack Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2013-10-28 18:38 -0700

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