[Rd] confusing all.equal output

peter dalgaard
2023-03-02T18:47:59Z

I believe the wording goes back to Martin Maechler many moons ago (AFAICT
towards the end of the last millennium.)

We might leave it to him to change it?

- Peter D.

> On 2 Mar 2023, at 19:30 , avi.e.gross at gmail.com wrote:
>
> I think if you step back, you can ask what the purpose of an error message
> is and who designs it.
>
> Is the message for the developer or others on their team or something an
> end-user knowing nothing about R will see.
>
> This reminds me a bit of legal mumbo jumbo that turns many reading it off
as
> it keeps talking about the party of the first part or the plaintiff as
> compared to somewhat straighter talk.
>
> The scenario is that you are comparing two things. Their names are not
> things like "target" or "current" so even other
programmers not involved in
> your code will pause and wonder.
>
> One view is to use phrases like first and second arguments/lists/whatever.
> You might talk about the one on the left (but using LHS is a bit opaque)
> versus the one on the right.
>
> But sometimes it can be too verbose. Sometimes the error message is being
> generated not where everything is clear.
>
> So ideally you could say:
>
> WARNING Danger Will Robinson.
> Comparing two things for equality.
> Result finds mismatches.
> There were NA found on the (left or right) that were not matched on the
> other side.
> Number of such found: 2
>
> If you had a Systems Engineer write detailed requirements that included
> something a bit better than the example and the programmer was able to
> supply the data using the words and guidelines, it might fit some needs but
> maybe not satisfy other programmers. But there are human factors people
> whose job it is to help choose among alternatives and although they may not
> choose well, letting a programmer come up with whatever they feel like is
> generally worse.
>
> Yes, in their microcosm centered on a dozen lines of code,
"current" and
> "target" may have meaning. But are they the intended user of the
product?
>
> -----Original Message-----
> From: R-devel <r-devel-bounces at r-project.org> On Behalf Of Antoine
Fabri
> Sent: Thursday, March 2, 2023 12:23 PM
> To: peter dalgaard <pdalgd at gmail.com>
> Cc: R-devel <r-devel at r-project.org>
> Subject: Re: [Rd] confusing all.equal output
>
> Good points. I don't mind the terminology since target and current are
the
> names of the arguments. As the function is already designed to stop at the
> first failing check we might not need to enumerate or count the mismatches,
> instead we could have "`NA` found in `target` but not in `current` at
> position <FIRST_MISMATCH>"
>
> 	[[alternative HTML version deleted]]
>
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--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com