[RFC] Explicit N/S and E/W suffixes

[maandree]

To avoid the error where users on the west side of the
prime meridian specify lon=100 instead of lon=-100
(for example), and analogously with lat if that also
happens, I suggest that a warning should emitted unless
lat is suffixed with [nNsS] and lon is suffixed with [eEwW].
A warning should also be emitted if - is.

So for example, instead of -l 50:-100 on would write
-l 50N:100W or -l 50n:100w. -l 50n:-100w would also
be accepted but emits a warning because it is ambiguous.

[jonls]

I understand that some people are having trouble with the negative/positive latitude/longitude and I agree with you that we can try to make it very clear how to specify the values correctly. I'm not sure this is the right solution though, as most people are actually able to follow the established standards, and read the help output and man page when in doubt. It is explained quite clearly in both places I think. Generating a warning would encourage people who have a working setup to go change their configurations, which is not very nice. Perhaps we can show the latitude, longitude with the N/S, E/W suffix whenever we print it or show it in the GUI? On top of that we could allow N/S, E/W suffixes on the input as an optional feature.

[maandree]

Next release will print N/S and E/W (pull request #90) so perhaps we should wait an see how well that solves the issue. But optional suffixes is a good idea.

[jonls]

This seems to have solved most of the confusion about this.