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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: REAL
Date: Wed, 14 Mar 2012 14:51:59 +0100
Date: 2012-03-14T14:51:59+01:00	[thread overview]
Message-ID: <1u0x151ebygpz$.1f4x12uo70ifu$.dlg@40tude.net> (raw)
In-Reply-To: 4f609d6a$0$6628$9b4e6d93@newsspool2.arcor-online.net

On Wed, 14 Mar 2012 14:30:17 +0100, Georg Bauhaus wrote:

> So it is better to keep the current
> types and effects and acquire the asset. Turns hazards into
> sources of achievement.

When you compute anything using conventional floating point arithmetic, the
result of this computation is within the bounds of the equivalent interval
computation, provided, CPU has no bugs in its ALU. This is a mathematical
fact.

Interval arithmetic does not compute anything differently. It just keeps
track of the error bounds.

The disadvantages comparing to normal arithmetic is that you need twice as
much memory (if the implementation is straightforward). This was an issue
when intervals were actively studied (60s-70s). No any problem now.

Comparing to analytical methods of error estimation. Intervals give a
pessimistic one. A manual analysis based on additional knowledge
(especially if variables are dependant) may sufficiently improve the
estimation. It is worth to remember that floating point arithmetic does no
any error estimation, whatsoever. In fact it is guaranteed to be
inaccurate, which is the asset, you wrote about.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de



  reply	other threads:[~2012-03-14 13:51 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-21 15:42 Verified compilers? Yannick Duchêne (Hibou57)
2012-02-24  1:41 ` Shark8
2012-02-24  8:52   ` Georg Bauhaus
2012-02-24 17:36   ` Peter C. Chapin
2012-03-06  1:27 ` Randy Brukardt
2012-03-06 17:24   ` Shark8
2012-03-06 17:43     ` Dmitry A. Kazakov
2012-03-06 19:03       ` Shark8
2012-03-07  5:33       ` Yannick Duchêne (Hibou57)
2012-03-07  9:12         ` Dmitry A. Kazakov
2012-03-07 17:49           ` Niklas Holsti
2012-03-07 20:17             ` Dmitry A. Kazakov
2012-03-07 23:28               ` Usefulness of Formal Notions in Programming (was: Verified compilers?) Georg Bauhaus
2012-03-08  9:24                 ` Usefulness of Formal Notions in Programming Dmitry A. Kazakov
2012-03-08 10:30                   ` Nasser M. Abbasi
2012-03-08 12:37                     ` Dmitry A. Kazakov
2012-03-08  0:42               ` Verified compilers? Randy Brukardt
2012-03-08  9:25                 ` Dmitry A. Kazakov
2012-03-08 18:10                   ` Niklas Holsti
2012-03-08 20:41                     ` Dmitry A. Kazakov
2012-03-08 18:02               ` Niklas Holsti
2012-03-08 20:40                 ` Dmitry A. Kazakov
2012-03-09  0:44                   ` Georg Bauhaus
2012-03-09 22:13                   ` Niklas Holsti
2012-03-10 10:36                     ` Dmitry A. Kazakov
2012-03-10 20:35                       ` Niklas Holsti
2012-03-11  9:47                         ` Dmitry A. Kazakov
2012-03-11 22:22                           ` Niklas Holsti
2012-03-12  5:12                             ` Niklas Holsti
2012-03-12  9:43                             ` Dmitry A. Kazakov
2012-03-14  8:36                               ` Niklas Holsti
2012-03-14  9:24                                 ` Georg Bauhaus
2012-03-14 11:14                                   ` REAL (was: Verified compilers?) stefan-lucks
2012-03-14 12:59                                     ` REAL Dmitry A. Kazakov
2012-03-14 13:30                                       ` REAL Georg Bauhaus
2012-03-14 13:51                                         ` Dmitry A. Kazakov [this message]
2012-03-14 20:37                                           ` REAL Brian Drummond
2012-03-14 21:52                                             ` REAL Dmitry A. Kazakov
2012-03-14 13:52                                         ` REAL georg bauhaus
2012-03-14 17:42                                         ` REAL Jeffrey Carter
2012-03-14 10:14                                 ` Verified compilers? Dmitry A. Kazakov
2012-03-14 20:13                                   ` Niklas Holsti
2012-03-11 10:55                         ` Georg Bauhaus
2012-03-10 13:46                     ` Brian Drummond
2012-03-07  1:00     ` Randy Brukardt
2012-03-07 12:42   ` Stuart
2012-03-08  1:06     ` Randy Brukardt
2012-03-08  9:04       ` Jacob Sparre Andersen
2012-03-08  9:37         ` Dmitry A. Kazakov
2012-03-08 11:23           ` Simon Wright
2012-03-08 12:27             ` Dmitry A. Kazakov
2012-03-08 10:23         ` Brian Drummond
2012-03-08 23:38           ` Bill Findlay
2012-03-09 13:56             ` Brian Drummond
2012-03-09 14:43               ` Shark8
2012-03-09 21:51                 ` Brian Drummond
2012-03-09 15:49               ` Bill Findlay
2012-03-09 20:34                 ` Brian Drummond
2012-03-09 19:40               ` Jeffrey Carter
2012-03-09 20:39                 ` Brian Drummond
2012-03-09 23:59               ` phil.clayton
2012-03-08 15:23         ` Peter C. Chapin
2012-03-09  2:04         ` Randy Brukardt
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