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<DIV><SPAN class=875132500-18072003><FONT face=Arial size=2>Hi
list,</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial size=2>I'm currently trying
to transform a polygon which is a rectangle. I get give extent coordinates
(minx,miny,maxx,maxy) in lat/long's and I then build a polygon out of it,
transforming it into a Mercator projection with a +150 longitude shift. I use a
query like:</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV><SPAN class=875132500-18072003> UPDATE extents SET
the_geom=transform(GeometryFromText('MULTIPOLYGON(((-180 -70 ,-180 85,180 85
,180 -70,-180 -70)))',4326),999001) WHERE id=13739;</SPAN></DIV></BLOCKQUOTE>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial size=2>The 999001
projection is a custom projection in the spatial_ref_sys table. Its definition
is identical to the Mercator projection (srid of 54004) except for an
addition of "+lon_0=150" in the proj4text.</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial size=2>When I run the query
above I get a rectangle draw (via mapserver) as a straight line running from 85
to -70 at the point where 180/-180 is. It should be a rectangle covering the
entire globe. I understand that PostGIS is taking the coordinates that I pass
and transforming the -180 and +180 to be the same point in
metres. You can see this in the geometry below:</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2>SRID=999001;MULTIPOLYGON(((3339584.7237982
-11028513.6309201,3339584.7237982 19929239.1133792,3339584.7237982
19929239.1133792,3339584.7237982 -11028513.6309201,3339584.7237982
-11028513.6309201)))</FONT></SPAN></DIV></BLOCKQUOTE>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial size=2>I've checked this
using cs2cs like follows:</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV><SPAN class=875132500-18072003><FONT face=Arial size=2>cs2cs
+proj=latlong +datum=WGS84 +to +proj=merc +lon_0=150</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2>0</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2>-16697923.62 0.00 0.00</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2>180</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2>3339584.72 0.00 0.00</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2>-180</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial size=2><SPAN
class=875132500-18072003><FONT face=Arial size=2>3339584.72
0.00 0.00</FONT></SPAN></FONT></SPAN></DIV></BLOCKQUOTE>
<DIV><SPAN class=875132500-18072003><FONT face=Arial size=2><SPAN
class=875132500-18072003></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial size=2><SPAN
class=875132500-18072003>Does any one have any suggestion on how I can ensure
that the polygon I create covers the entire globe?</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial size=2></FONT></SPAN><SPAN
class=875132500-18072003><FONT face=Arial size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2>Thanks,</FONT></SPAN></DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=875132500-18072003><FONT face=Arial
size=2>Benjamin</FONT></SPAN></DIV></BODY></HTML>