[Gdal-dev] Tool to convert shapefile from [-180, 180] to [0,
archer at eskimo.com
Thu Jun 15 11:02:43 EDT 2006
On Thu, 15 Jun 2006, Charles Wivell wrote:
> The shift you should use if you want the values between -180 and
> 180 for values less than -180 would be:
I'm not interested in the conversions in this case as they're
Are apps normally designed to handle 0-360 or are files expected to
conform to -180 to +180? I have two types of files now that don't
correspond to -180 to +180. I understand that for other planets it
is common to do the 0-360 thing.
Also these questions:
> *) What should an application do with a shapefile that contains
> polygons with longitudes in the -189.9 to -180.0 range? Is there an
> easy way to split up the shapes so they don't fall off the edge of
> the earth?
Note: Our app uses unprojected lat/long in WGS84 only for display.
-180 is the left edge, +180 is the right edge (if zoomed out far
enough to see them both). Drawing polygons or lines that cross the
180 boundary is a big hassle, we'd have to split them before
Curt, WE7U. APRS Client Comparisons: http://www.eskimo.com/~archer
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