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

2012-04-25 Thread Steven D'Aprano
Stephen J. Turnbull wrote: On Wed, Apr 25, 2012 at 1:19 AM, Jim Jewett wrote: I'm still a little fuzzy on *why* it shouldn't count as a monotonic clock. So are the people who say it shouldn't count (unless you're speaking of the specific implementation on Unix systems, which can go backward

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

2012-04-24 Thread Stephen J. Turnbull
On Wed, Apr 25, 2012 at 1:19 AM, Jim Jewett wrote: > I'm still a little fuzzy on *why* it shouldn't count as a monotonic > clock. So are the people who say it shouldn't count (unless you're speaking of the specific implementation on Unix systems, which can go backward if the admin or NTP decides

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

2012-04-24 Thread Victor Stinner
>> I don't know any monotonic with a defined epoch or >> mappable to the civil time. > > The very basic "seconds (not even milliseconds) since the beginning of > 1970" fits that definition, but doesn't seem to fit what most people > mean by "Monotonic Clock". > > I'm still a little fuzzy on *why* i

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

2012-04-24 Thread Jim Jewett
On Tue, Apr 24, 2012 at 6:38 AM, Victor Stinner wrote: >> Monotonic >> - >> This is a particularly tricky term, as there are several subtly >> incompatible definitions in use. > Is it a definition for the glossary? One use case for a PEP is that someone who does *not* have a background

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

2012-04-24 Thread Victor Stinner
> Precision > - > > This is another tricky term, This is a good reason why it is no more used in the PEP :-) > Note that "precision" as reported by the clock itself may use yet > another definition, and may differ between clocks. Some C function provides the frequency of the clock (and s

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

2012-04-24 Thread Victor Stinner
> Monotonic > - > > This is a particularly tricky term, as there are several subtly > incompatible definitions in use. Is it a definition for the glossary? >  C++ followed the mathematical > definition, so that a monotonic clock only promises not to go > backwards. The "C++ Timeout Speci

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

2012-04-24 Thread Stephen J. Turnbull
Very nice! Two possible clarifications: On Tue, Apr 24, 2012 at 10:58 AM, Jim Jewett 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 s

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

2012-04-23 Thread Nick Coghlan
I like the updated glossary - very good summary of the relevant terminology and common points of confusion. One minor gripe below (and it *is* minor, despite the amount of text explaining my point of view...) On Tue, Apr 24, 2012 at 11:58 AM, Jim Jewett wrote: > Real Time > - > > Time in