<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial, helvetica, sans-serif;font-size:10pt"><div>Thankyou Nicolas,</div><div>So you are telling me that the SRID of WGS84 is 4326 and that the coordinates of WGS84 are latitude and longitude? </div><div>I'm going to use these resulting coordinates for the GoogleMaps api, and I am guessing that input to the latter can be WGS84.</div><div>Henri</div><div style="font-family:arial, helvetica, sans-serif;font-size:10pt"><br><div style="font-family:arial, helvetica, sans-serif;font-size:13px"><font size="2" face="Tahoma"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Nicolas Ribot <nicolas.ribot@gmail.com><br><b><span style="font-weight: bold;">To:</span></b> PostGIS Users Discussion <postgis-users@postgis.refractions.net><br><b><span style="font-weight: bold;">Sent:</span></b> Sun, January 23, 2011 12:31:44
PM<br><b><span style="font-weight: bold;">Subject:</span></b> Re: [postgis-users] How to do inverse projection?<br></font><br>
> Hi,<br>> I'm a bit naIve when it comes to this stuff about projections and<br>> coordinates.<br>> Suppose I have data that have been projected with a particular system (i<br>> suppose the SRID determines which projection it is)<br>> How do I get the inverse projection in terms of latitude and longitude of a<br>> point from the point's coordinates in the projection?<br>> Is there a general function for that in PostGis?<br>> Thanks<br>> Henri<br><br>Hi,<br>Use st_transform(geometry, srid)<br><span>(<a target="_blank" href="http://postgis.org/documentation/manual-1.5/ST_Transform.html">http://postgis.org/documentation/manual-1.5/ST_Transform.html</a>), for instance:</span><br><br>(A point in french projection, srid=2154, tranformed to WGS84, srid=4326 ) :<br>select st_transform(st_geomFromText('POINT ( 576376 6265916)', 2154),
4326);<br><br>Nicolas<br>_______________________________________________<br>postgis-users mailing list<br><a ymailto="mailto:postgis-users@postgis.refractions.net" href="mailto:postgis-users@postgis.refractions.net">postgis-users@postgis.refractions.net</a><br><span><a target="_blank" href="http://postgis.refractions.net/mailman/listinfo/postgis-users">http://postgis.refractions.net/mailman/listinfo/postgis-users</a></span><br></div></div><div style="position:fixed"></div>
</div></body></html>