[R-pkg-devel] r-quantities seeking feedback

[David Hugh-Jones]

Hi Iñaki,

OK, it sounds like we have no practical disagreement: you're planning to
keep separate packages and then have a third one for integration. That will
be fine for people like me who don't necessarily want to specify units for
our regressions. I look forward to seeing this!

Cheers,
David

On 7 October 2017 at 13:00, Iñaki Úcar <i.ucar86 at gmail.com> wrote:

> 2017-10-06 22:28 GMT+02:00 David Hugh-Jones <davidhughjones at gmail.com>:
> > Many measurements have no unit, but some uncertainty - e.g. the b and se
> > from an arbitrary regression. Can you give specific examples of the
> > advantages from binding these packages tightly together?
>
> As Duncan already pointed out, the units of b and se from an arbitrary
> regression depend on the units of your variables. The advantages from
> integrating both packages are the combination of advantages from each
> one with the same workflow as if you were working with bare numbers.
>
> It seems that you are already aware of the advantages of automatic
> error propagation. Regarding the units package, it is very useful for
> painless conversion of units. A conversion from kg to g is elementary,
> but some others require more care, for example J to eV, or N.m-1 to
> dyn.cm-1. In electromagnetism, it is very common to work with the CGS
> units system, and an automatic conversion from/to the SI comes in
> handy.
>
> If you are not persuaded already, we can also talk about the Mars
> Climate Orbiter, a robotic space probe launched by NASA on 1998 which
> disintegrated in Mars' upper atmosphere due to a computation with
> wrong units.
>
> Iñaki
>

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