[Octave-bug-tracker] [bug #65291] [octave forge] (mapping) degrees2dms produces incorrect results

[Philip Nienhuis]

Update of bug #65291 (group octave):

                  Status:               Confirmed => Patch Submitted        

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Follow-up Comment #15:

Thank you very much Anonymous for the contribution.
Hopefully I'll be able to review it in the coming weeks, I hope you're not
offended by that time schedule.
I'll also check out degrees2dm.m (bug #65508).

Some initial comments:

As to sign handling - isn't it just so that the input sign simply carries over
to only the degrees part? I'm unsure here, but TTBOMK, DMS coordinates in real
world navigation are represented as <dd[NSWE] mm ss> where negative signs are
are morphed to S or E and the minutes and seconds values point in the
pertinent N / S / E or W direction.

Then, I haven't tested the degrees2* functions but I know that many Matlab
mapping functions happily accept latitude values that are larger (or smaller)
than 90 (or -90) degrees; same for longitudes > 360 or < -360.  I don't know
any use for such values (but who am I, I'm just a hydrogeologist and a hobby
sea sailor using maps quite regularly :-) ). So in various mapping functions
(mainly coordinate transforms IIRC, it's a while ago) I've added wrapping
functions - I haven't looked yet but degrees2dms.m and degrees2dm.m may also
need it and/or benefit from it.
Now, looking at comment #13 for the first time I see some questionable Matlab
outputs. For values of +-Inf I'd rather see a warning or maybe even an error.
Returning Infs (that contrary to NaNs allow *some* further computations) may
have been chosen by TMW to allow processing to continue, implicitly accepting
the risk of hard-to-uncover errors or even silently returned wrong results in
later stages. Coming from the practical rather than theoretical side I tend to
find this a bit of an irresponsible choice.
What would be your opinion?

As to anonimity: sure, you're not the first, but it'll have to pushed under
someone's name and that'll probably be mine. But I'll credit "Anonymous" in
the commit message.
OK?


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