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

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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