[time-nuts] Misuse of word "decimate" (was Re: Short term 10MHz source)

[Bob kb8tq]

Hi

Pretty much every DVM out there spits out more digits than make sense accuracy wise. It
certainly makes sense to note in the doc’s what the accuracy / resolution of the device is.
Keeping the extra digit does not cost anything in this case. It *might* come in useful if somebody
spent the time to work out how to phase modulate the reference to “fill in the gaps”. As 
Magnus has noted in the past, HP did this on real world counters once upon a time….

Bob

> On Jan 10, 2019, at 7:54 AM, John Ackermann. N8UR <jra at febo.com> wrote:
> 
> And just to clarify the subject matter -- the TICC data output contains 12 decimal places, i.e., 1 ps precision.  The actual resolution is about 55 ps, so the last digit is pure noise, and the penultimate digit should really be either 5 or 0.  
> 
> To eliminate the distraction of the noise, It's under consideration to zero the last decimal place, and *maybe* to round to 50 ps.  I think the last digit is a no-brainer, but am more hesitant about the rounding.
> 
> Coming soon to a git near you...
> 
> On Jan 10, 2019, 7:13 AM, at 7:13 AM, Adrian Godwin <artgodwin at gmail.com> wrote:
>> Truncate, to me at least, means to shorten : ie to remove some
>> precision by
>> rounding off lower bits.
>> 
>> I agree that the source of the word 'decimate' is unclear, but I think,
>> within the field of DSP, it has a reasonably precise definition whether
>> or
>> not that corresponds with wider usage or derivation.
>> 
>> 
>> 
>> On Thu, Jan 10, 2019 at 12:02 PM Peter Vince <petervince1952 at gmail.com>
>> wrote:
>> 
>>> In his comment below, Mark has used the word "decimate".  There is
>> much
>>> debate about what this word means (presently, and/or in the past),
>> but
>>> common explanations refer back to Roman times when they apparently
>> killed
>>> one person in ten as a punishment, and similarly "tithes" - or taxes,
>> where
>>> one in ten was taken.  Now OK, you can argue this until the cows come
>> home,
>>> but the result is that the meaning isn't crystal clear, and
>> particularly on
>>> a technical forum where precision is paramount, and the entire reason
>> we
>>> are here, I believe accuracy and clarity of expression is also
>> important.
>>> In this instance, I believe "truncate" would be a better word.
>>> 
>>> </rant>  :-)
>>> 
>>>     Regards,
>>> 
>>>          Peter Vince
>>> 
>>> On Wed, 9 Jan 2019 at 23:56, Mark Sims <holrum at hotmail.com> wrote:
>>>> ...
>>>> And as far as decimating the TICC output values in firmware...
>> please
>>> don't.   Let the user decimate the values if they want to.
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