[Python-Dev] (time) PEP 418 glossary V2

Stephen J. Turnbull stephen at xemacs.org
Tue Apr 24 09:26:35 CEST 2012


Very nice!  Two possible clarifications:

On Tue, Apr 24, 2012 at 10:58 AM, Jim Jewett <jimjjewett at gmail.com> wrote:
> Glossary
> ========
> Bias
> ----
>
> Lack of accuracy that is systematically in one direction, as opposed to
> random errors.  When a clock is `Adjusted`_, durations overlapping the
> adjustment will show a Bias.

"Conversely, if the clock has experienced `Drift`_, its reports of
`Absolute Time`_ will show Bias until the adjustment takes place."


> Counter
> -------
>
> A clock which increments each time a certain event occurs.  A counter
> is strictly monotonic in the mathematical sense, but does not meet
> the typical definitions of Monotonic_ when used of a computer clock.
> It can be used to generate a unique (and ordered) timestamp, but these
> timestamps cannot be mapped to `Civil Time`_; Tick_ creation may well

"mapped" -> "algorithmically mapped"

> be bursty, with several advances in the same millisecond followed
> by several days without any advance.
> Duration_ measurements become less comparable, in return for providing
> a more accurate `Absolute Time`_.


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