<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div apple-content-edited="true"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>Hi,</div><div><br></div><div><br></div><div>Below an example, throught PostGIS </div><div>with GEOS 3.3.5-CAPI-1.7.5:</div><div><br></div><div><br></div><div>SELECT ST_IsValidReason(</div><div> 'MULTIPOLYGON(((0 0,1 0,1 1,0 1,0 0)),((1 0,2 0,2 1,1 1,1 0)))'::geometry</div><div> );</div><div><br></div><div><br></div><div>Output: Self-intersection[1 0]</div><div><br></div><div><br></div><div>After looking in SFS and ISO 19107, </div><div>we didn't find at first sight </div><div>why such a geometry should be invalid.</div><div><br></div><div><br></div><div>Could you give us some light on it ?</div><div><br></div><div><br></div><div>Thanks in advance,</div><div><br></div><div><br></div><div>--</div></div><div>Olivier</div></div></span></span>
</div>
<br></body></html>