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From: Ted Dennison <dennison@telepath.com>
Newsgroups: comp.lang.ada
Subject: Re: Duration vs. Ada.Real_Time
Date: Fri, 26 Jan 2001 21:32:01 GMT
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Date: 2001-01-26T21:32:01+00:00
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In article <3A71E4F6.6D7015AD@acm.org>,
  Marin David Condic <mcondic.auntie.spam@acm.org> wrote:

> I would think that a reasonable implementation of Ada for realtime
> systems would want to insure that the precision had some relationship
> to the accuracy of the clock available. Obviously, for
Do you mean "accuracy" or "frequency"?
...
> be changed for the language. But stating, for example, that the
> precision of a time representation can go down to atto-seconds can
> easily mislead one to believe that the measurement of time is going to
> be something close to that precision.

This gets back around to the issue we were discussing a couple of weeks
ago. If the language requires units of seconds, but the system's clock
used some incompatable system like Hz (eg: 60 Hz, which can't be
represented exactly in terms of fixed-point seconds), then you (or at
least *I*) would actually prefer a much higher precision, so that your
error in representation isn't so great when you start to do math with it.

--
T.E.D.

http://www.telepath.com/~dennison/Ted/TED.html


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