[QGIS-Developer] Use of NE(SW) in the showing of (ordered) coordinates within QGIS

[Greg Troxel]

Richard Duivenvoorde via QGIS-Developer <qgis-developer at lists.osgeo.org>
writes:

> In 3.24 you will see something like "WGS84 5.2 52,3"
> While in master it shows: "WGS84 52.3N 5.2E"  (note the N and E)
>
> For WGS84 I think this is normal (to show WSEN), but for other crs's I
> think it is overkill?
>
> In 3.24: "EPSG:28992 (150000,450000)"
> In master now I see: "EPSG:28992 (150702E,466216N)"

I think the real question is if these are expected to be useful for
humans to look at, or if they are expected to be machine-processable
somehow.

And if they are for humans, what are the humans doing with them?

And if they are hints for what will be copied, but the copied string has
just numbers and a comma so that copied string is machine procesable.
Or if it's a mini geojson point object (just kidding; that seems a bit
much).

As for x and y, those are projection concepts, and for WGS84:

  using x for latitude and y for longitude is basically declaring a
  projection, and for 4326, that isn't so even that's what people often
  choose to do when displaying 4326 for nerds

  WGS84 ECEF has axes, and they aren't the same as how you are using
  them.  WGS84 geographic does not have x and y axes.

For UTM/LCC sorts of CRSes, the axes are (usually) easting and northing
and I don't see then written x and y.


There is some messiness in that if one sets a project CRS to 4326, then
the display is x=lon, y=lat, which is a projection.  Basically if you
have have a project CRS that isn't a projection, then there is further
step to relate the CRS axes to display x and y, and that's implicit.
For many things, given the dominance of north up, there is an obvious
answer, but it's still an assumption.


Part of the underlying trouble is that in qgis/proj we blur:

  datum
  projection

into

  CRS

except that some CRS are datum only, and some are datum+projection.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 194 bytes
Desc: not available
URL: <http://lists.osgeo.org/pipermail/qgis-developer/attachments/20220411/908d0cb0/attachment.sig>