[mapserver-users] Off-center World Maps

[Jan Hartmann]

Hello MS-users,

Is it possible to display a projected world map centered on an arbitrary
meridian? The Proj4 manual shows some maps centered on the Americas, using
the Proj parameter "lon_0=90w". When I try this with MapServer
(php_mapscript for Windows, CVS-version, Proj-4.4.5), I generally get a
recognizable world map with America in the middle, but with lots of faulty
lines crossing the dateline. Some projections leave out a hemisphere or put
it in the wrong place. This also happens when I don't use a regular map, but
compute a graticule within Mapscript.

Same problem with maps centered on a different latitude. For example, is it
possible to plot a map centered on the North Pole? I have not found a way to
plot even a faulty map this way.

Thanks,



Jan Hartmann
Department of Geography
University of Amsterdam
jhart at frw.uva.nl