Re: [PSAMP] PSAMP-INFO IE realtiveError

[Andrew Johnson <[e-mail]>]

[SNIP]
> > >> The intention was to say that the clock is 5 minutes slow, +/- 10
> > >> seconds - so there's both an absolute error and a relative error.
> > >>
> > >
> > > NOW I finally understand what you meant by fixedError initially !!
> > > This I would not consider as error. Any fixed deviation I would
> > rather
> > > name "offset"...
> > > If it is known couldn't you add it to the value and report the
> > correct
> > > time?
> > 
> > In that case there would be no need to ever report "absoluteError" -
> > because all the original measurements can be corrected before being
> > exported.
> 
> Maybe for clarification:
> The absoluteError that I propose is different from what you intended by
> fixedError. absoluteError is a maximum error that you would expect due
> to the inaccurate measurement (e.g. the timestamp may vary by +/- 5 ms).
> The real error that you make during measurements is unknown and can
> vary. Your fixedError is different. It is a fixed and known offset for
> the measured values, correct?

I think the absoluteError is the same as the originally fixedError.  In
Paul's example above the fixedError was +/- 10 seconds.  I'm not sure
how you would communicate the "5 minutes slow" part...

The original idea was fixedError would say this is accurate to within X
units.  Both the fixed and the absolute error can be used together, but
you just have to go with the least accurate one.  For example, if my
bathroom scales have a fixed error of 0.25kg and a relative error of
0.5%, then they can weigh a person very accurate, but are rubbish for
weighing mice:
  Person1:   81.50kg +/- 0.4kg
  Mouse1:     0.25kg +/ 0.25kg

Cheers

Andrew

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