[postgis-users] How do I span the international date line?

[Brent Wood]

--- Paul Tomblin <ptomblin at xcski.com> wrote:

> Is there a way to make a rectangle that goes from, say, 45N 179W to 45S 179E 
> without going through 0?  Is there a way to make one that goes from the same 
> coordinates that *does* go through 0?

Hi Paul,

Nothing straightforward.

You can use longitudes between 0-360 instead of +-180, (so 170W=190) this
migrates the problem 180 degrees, but doesn't cure it, and you really need to
migrate all your data to one or the other.

I even have maps (tables) with data from -180 to 360, with the western
hemisphere replicated each side of the eastern. Not an elegant approach, but it
did resolve one web mapping issue requiring a seamless lat/long world
coastline. 

You can also store your data in projected coordinates instead of (or as well
as) 
lat/long. In this case displaying your data in lat/long will typically draw
lines & polygons across the world, but they normally plot OK in the projection.


HTH,

  Brent Wood.


> 
> 
> -- 
> Paul Tomblin <ptomblin at xcski.com> http://blog.xcski.com/
> Considering the number of wheels Microsoft has found reason to invent,
> one never ceases to be baffled by the minuscule number whose shape even
> vaguely resembles a circle.  -- [unknown]
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