From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: accuracy
Date: Fri, 9 Mar 2007 09:33:41 +0100
Date: 2007-03-09T09:33:41+01:00 [thread overview]
Message-ID: <p87mtsns4of0.hhld0y03415s.dlg@40tude.net> (raw)
In-Reply-To: n4%Hh.36034$E02.14558@newsb.telia.net
On Thu, 08 Mar 2007 21:18:11 GMT, Bj�rn Persson wrote:
> Dmitry A. Kazakov wrote:
>
>> If it were just inaccurate then the obtained values would be like
>> ThreadTime + Error where Error has zero mean.
>
> No, that's "imprecise".
No. The sets "accurate" and "precise" do not contain each other. Which
means that measurement can be precise and accurate, precise but inaccurate,
imprecise but accurate or imprecise and inaccurate.
As for GetThreadTimes, its absolute precision is 1ms. Its suggested
absolute accuracy should be one time quant (which duration depends on the
system settings). The later does not hold, because the error is in fact not
bounded.
> Shots distributed evenly over a shooting target is
> bad precision. A tight group of shots at one side of the target is good
> precision but bad accuracy.
That's right. This is why GetThreadTimes is not just inaccurate, it is
precisely wrong.
BTW, precisely wrong /= imprecise. (:-))
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2007-03-09 8:33 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-01-29 11:57 Does Ada tasking profit from multi-core cpus? Gerd
2007-01-29 12:04 ` Georg Bauhaus
2007-01-30 13:55 ` Gerd
2007-02-09 10:18 ` karl
2007-02-09 11:03 ` Stefan Lucks
2007-02-09 11:35 ` Ludovic Brenta
2007-03-04 17:54 ` jpluto
2007-03-05 10:08 ` Ludovic Brenta
2007-03-05 13:12 ` Dmitry A. Kazakov
2007-03-06 5:33 ` tmoran
2007-03-06 8:44 ` Dmitry A. Kazakov
2007-03-07 7:52 ` tmoran
2007-03-07 9:31 ` tmoran
2007-03-06 9:40 ` Colin Paul Gloster
2007-03-06 12:47 ` Jeffrey Creem
2007-03-06 14:44 ` Georg Bauhaus
2007-03-06 16:53 ` Dr. Adrian Wrigley
2007-03-06 18:58 ` tmoran
2007-03-07 10:11 ` Colin Paul Gloster
2007-03-07 18:47 ` tmoran
2007-03-06 18:51 ` Jeffrey R. Carter
2007-03-16 14:29 ` Arguments for single-mutex-exclusion on protected types (Was: Does Ada tasking profit from multi-core cpus?) Jacob Sparre Andersen
2007-03-17 5:26 ` Jeffrey R. Carter
2007-03-17 17:22 ` Robert A Duff
2007-03-17 17:52 ` Jeffrey R. Carter
2007-03-17 23:06 ` Randy Brukardt
2007-03-18 17:57 ` Robert A Duff
2007-03-19 21:49 ` Randy Brukardt
2007-03-20 0:55 ` Jeffrey R. Carter
2007-03-20 1:36 ` Randy Brukardt
2007-03-20 16:32 ` Jeffrey R. Carter
2007-03-20 17:51 ` Randy Brukardt
2007-03-21 0:10 ` Jeffrey R. Carter
2007-03-26 23:38 ` Robert A Duff
2007-03-26 23:24 ` Robert A Duff
2007-03-17 10:25 ` Dmitry A. Kazakov
2007-03-18 17:15 ` Arguments for single-mutex-exclusion on protected types Jacob Sparre Andersen
2007-03-18 18:50 ` Dmitry A. Kazakov
2007-03-20 12:38 ` Florian Weimer
2007-03-07 3:58 ` Does Ada tasking profit from multi-core cpus? Steve
2007-03-07 8:39 ` Dmitry A. Kazakov
2007-03-08 5:21 ` Randy Brukardt
2007-03-08 10:15 ` Dmitry A. Kazakov
2007-03-08 21:18 ` accuracy (was: Does Ada tasking profit from multi-core cpus?) Björn Persson
2007-03-09 8:33 ` Dmitry A. Kazakov [this message]
2007-03-10 1:39 ` accuracy Randy Brukardt
2007-03-10 9:11 ` accuracy Dmitry A. Kazakov
2007-03-11 3:03 ` accuracy Randy Brukardt
2007-03-11 5:21 ` accuracy tmoran
2007-03-11 8:52 ` accuracy Dmitry A. Kazakov
2007-03-11 13:57 ` accuracy Pascal Obry
2007-03-11 14:16 ` accuracy Dmitry A. Kazakov
2007-03-11 14:37 ` accuracy Pascal Obry
2007-03-11 15:50 ` accuracy Dmitry A. Kazakov
2007-03-11 17:38 ` accuracy Pascal Obry
2007-03-11 18:48 ` accuracy Dmitry A. Kazakov
2007-03-12 20:20 ` accuracy Randy Brukardt
2007-03-13 9:33 ` accuracy Dmitry A. Kazakov
2007-03-10 14:53 ` accuracy Stephen Leake
2007-03-10 18:36 ` accuracy Cesar Rabak
2007-03-05 18:46 ` Does Ada tasking profit from multi-core cpus? Jeffrey R. Carter
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