<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 10.10.2013, at 14:06, Iván Sánchez Ortega <<a href="mailto:ivan@sanchezortega.es">ivan@sanchezortega.es</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">El Jueves, 10 de octubre de 2013 13:16:42 Jaak Laineste escribió:<br><blockquote type="cite">Isn't there really better solution than dual-transformation? [...] Good <br>solution would be to implement buffer function from latitude/longitude <br>directly, say buffer(lat,lon,buffer_meters). Any takers?<br></blockquote><br>Actually, what you want is a buffer(lat, lon, degrees) algorithm that works on <br>polar coordinates on a topological sphere/geoid (as opposed to cartesian <br>coords on a plane).<br><br><br>But if PostGIS geography hasn't implemented that, my bet is that no one has. <br>Yet.<br></blockquote></div><br><div><br></div><div>You can calculate buffer around point quite easily with algorithm like <a href="http://williams.best.vwh.net/avform.htm#LL">http://williams.best.vwh.net/avform.htm#LL</a> , but generic buffer implementation, for lines/polygons would be bigger tasks for sure. Spherical JTS would be nice :)</div><div><br></div><div>Jaak</div></body></html>