[Python-Dev] PEP 418: Add monotonic time, performance counter and process time functions

Cameron Simpson cs at zip.com.au
Wed Apr 18 01:36:30 CEST 2012

On 17Apr2012 08:35, R. David Murray <rdmurray at bitdance.com> wrote:
| On Tue, 17 Apr 2012 14:48:22 +1000, Cameron Simpson <cs at zip.com.au> wrote:
| > On 16Apr2012 01:25, Victor Stinner <victor.stinner at gmail.com> wrote:
| > | I suppose that most people don't care that "resolution" and
| > | "precision" are different things.
| > 
| > If we're using the same definitions we discussed offline, where
| > 
| >   - resolution is the units the clock call (underneath) works in (for
| >     example, nanoseconds)
| > 
| >   - precision is the effective precision of the results, for example
| >     milliseconds
| > 
| > I'd say people would care if they knew, and mostly care about
| > "precision".
| I think what the user cares about is "what is the smallest tick that
| this clock result will faithfully represent?".

That is what "precision" is supposed to mean above. I suspect we're all in
agreement here about its purpose.

| To use other words, what the users cares about are the error bars on
| the returned result.

Yes. And your discussion about the hw clock exceeding the API resulution
means we mean "the error bars as they escape from the OS API".

I still think we're all in agreement about the meaning here.
Cameron Simpson <cs at zip.com.au> DoD#743

Often the good of the many is worth more than the good of the few. Saying
"if they have saved one life then they are worthwhile" places the good of the
few above the good of the many and past a certain threshold that's a
reprehensible attitude, for which I have utter contempt.

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