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We're making a light web front to a database, and I saw this in a test screenshot:

XY values in lat long boxes

Despite those coordinates being nowhere near North America, the "latitude/longitude" label for those coordinates really ruffled my jimmies. This got me wondering if there is a generic yet unambiguous term for each axis.

The first idea that came up was to just change the labels to X and Y Easting and Northing, but my understanding is those are terms used specifically for Cartesian coordinates. If the CRS was 4269, then the labels we have now would be correct.

We can probably derive the proper axes labels from the CRS, but I thought I'd ask if there's an accepted generic term (other than "value that increments along the north axis") to just sidestep the issue.

  • "X" and "Y" are valid if you present them in the correct order (Latitude is Y). – Vince Dec 26 '14 at 18:19
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    @Vince Only if you're using a CRS that specifies that. There are systems that label the Northing as X and Easting as Y. Mintx, why not check the CRS type and change the labels to match? – mkennedy Dec 26 '14 at 19:53
  • UTM is a Cartesian coordinate system. – whuber Dec 27 '14 at 22:50
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If you're seeking generic terms, which are independent of the shape of the coordinate reference surface (planar or spheroidal) for coordinate axes, you're out of luck.

For planar reference surfaces, the terms are northings and eastings (or in very rare cases, southings and westings).

For spheroidal reference surfaces, the terms are latitude and longitude (for N-S and E-W angular values, respectively).

What is not consistent, because it depends on the application context or the discipline being served, is the order; it can be N,E or E,N, and lat,lon or lon,lat.

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My suggestion is to go with your "if we have to" concept at the end, and not hard-code those into the UI. Instead, make the Coordinate system a combo-box at the top of that part of the UI, and then generate whatever the axes are from the user's selection in that combo-box.

If that is really an input box and the CRS terms are going to change fairly often (e.g. lon / lat and northing / easting), its likely that the user will get confused at some point. Applying sanity checks on the values (where possible) seems like a good investment in time.

Note that there are CRS that have more than two axes, although it isn't clear if that will affect your implementation.

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