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<div dir="ltr" data-setdir="false">Yep, <br></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Either use a Geography datatype as Neil describes here, or create the line with longitudes in the 0-360 space instead of +-180... so 170W = 190 instead of -170.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">You can use the ST_ShiftLongitude() function to switch between 0-360 & +-180 longitude spaces (EPSG supports both for 4326), but proj only supports +-180 for reprojection.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Brent Wood<br></div><div><br></div>
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On Wednesday, September 25, 2019, 7:36:46 AM GMT+12, Neil Freeman <neil@firststreet.org> wrote:
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<div><div id="ydpb5e28434yiv8546746782"><div>Paul-<div class="ydpb5e28434yiv8546746782"><br class="ydpb5e28434yiv8546746782"></div><div class="ydpb5e28434yiv8546746782">You can use a Geography type to automatically handle dateline crossing. This is a good resource on the differences between Geography and Geometry types: <a href="https://postgis.net/workshops/postgis-intro/geography.html" class="ydpb5e28434yiv8546746782" rel="nofollow" target="_blank">https://postgis.net/workshops/postgis-intro/geography.html</a></div><div class="ydpb5e28434yiv8546746782"><br class="ydpb5e28434yiv8546746782"></div><div class="ydpb5e28434yiv8546746782">Generating a line from your sample data would look something like this (decimals clipped for readability):</div><div class="ydpb5e28434yiv8546746782"><br class="ydpb5e28434yiv8546746782"></div><div class="ydpb5e28434yiv8546746782">SELECT ST_Geographyfromtext('LINESTRING(178.9 -37.5,-179.9 -38.4,-179.7 -38.4)');</div><div class="ydpb5e28434yiv8546746782"><div class="ydpb5e28434yiv8546746782"><br class="ydpb5e28434yiv8546746782"></div><div class="ydpb5e28434yiv8546746782">Converting the data from minutes and seconds to decimals could be done in SQL or elsewhere.</div><div class="ydpb5e28434yiv8546746782"><br class="ydpb5e28434yiv8546746782"></div><div class="ydpb5e28434yiv8546746782">While PostGIS will correctly handle calculations with the geography, desktop GIS programs might have display glitches depending on the map projection. In QGIS I was able to correctly view your sample line when using a southern polar projection, but not when using a standard mercator projection.</div><div class="ydpb5e28434yiv8546746782"><br class="ydpb5e28434yiv8546746782"></div><div class="ydpb5e28434yiv8546746782">-Neil</div><div class="ydpb5e28434yiv8546746782">
<div style="color:rgb(0, 0, 0);font-family:Helvetica;font-size:13px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;"><br class="ydpb5e28434yiv8546746782Apple-interchange-newline"></div></div><div><blockquote type="cite" class="ydpb5e28434yiv8546746782"><div class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" style="font-family:-webkit-system-font, Helvetica, sans-serif;color:rgb(127, 127, 127);"><b class="ydpb5e28434yiv8546746782">From: </b></span><span class="ydpb5e28434yiv8546746782" style="font-family:-webkit-system-font, Helvetica, sans-serif;"><<a href="mailto:paul.malm@lfv.se" style="color:purple;" class="ydpb5e28434yiv8546746782" rel="nofollow" target="_blank">paul.malm@lfv.se</a>></span></div><div class="ydpb5e28434yiv8546746782"><div style="font-family:Helvetica;font-size:13px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;margin:0px;" class="ydpb5e28434yiv8546746782"><span style="font-family:-webkit-system-font, Helvetica, sans-serif;color:rgb(127, 127, 127);" class="ydpb5e28434yiv8546746782"><b class="ydpb5e28434yiv8546746782">Subject:<span class="ydpb5e28434yiv8546746782Apple-converted-space"> </span></b></span><span style="font-family:-webkit-system-font, Helvetica, sans-serif;" class="ydpb5e28434yiv8546746782"><b class="ydpb5e28434yiv8546746782">[postgis-users] Lines crossing longitude 180 -180</b><br class="ydpb5e28434yiv8546746782"></span></div><div style="font-family:Helvetica;font-size:13px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;margin:0px;" class="ydpb5e28434yiv8546746782"><span style="font-family:-webkit-system-font, Helvetica, sans-serif;color:rgb(127, 127, 127);" class="ydpb5e28434yiv8546746782"><b class="ydpb5e28434yiv8546746782">Date:<span class="ydpb5e28434yiv8546746782Apple-converted-space"> </span></b></span><span style="font-family:-webkit-system-font, Helvetica, sans-serif;" class="ydpb5e28434yiv8546746782">September 24, 2019 at 3:18:22 AM EDT<br class="ydpb5e28434yiv8546746782"></span></div><div style="font-family:Helvetica;font-size:13px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;margin:0px;" class="ydpb5e28434yiv8546746782"><span style="font-family:-webkit-system-font, Helvetica, sans-serif;color:rgb(127, 127, 127);" class="ydpb5e28434yiv8546746782"><b class="ydpb5e28434yiv8546746782">To:<span class="ydpb5e28434yiv8546746782Apple-converted-space"> </span></b></span><span style="font-family:-webkit-system-font, Helvetica, sans-serif;" class="ydpb5e28434yiv8546746782"><<a href="mailto:postgis-users@lists.osgeo.org" style="color:purple;text-decoration:underline;" class="ydpb5e28434yiv8546746782" rel="nofollow" target="_blank">postgis-users@lists.osgeo.org</a>><br class="ydpb5e28434yiv8546746782"></span></div><br style="font-family:Helvetica;font-size:13px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;" class="ydpb5e28434yiv8546746782"><br style="font-family:Helvetica;font-size:13px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;" class="ydpb5e28434yiv8546746782"><div class="ydpb5e28434yiv8546746782WordSection1" style="font-family:Helvetica;font-size:13px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;"><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">Hi,</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">I’m creating a table with LineStrings in SRID 4326 from lines with coordinates like this:</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S37323578E178560795</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S38161687W179595994</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S38270000W179440000</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S38414463E179595994</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S39394800E178553000</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S40224800E178060600</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S41504422E176164722</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S42513000E175030000</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S43372622E174062536</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S45135100E172134000</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S48090000E168160000</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S45550000E165180000</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S42254200E169201800</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S41580000E169501800</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">S41253091E170232389</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">As you can see the crosses 180/-180 longitude several times which results in long line segments all over the map from east to west.</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">Is there anyone who have solved this problem in a fairly easy way?</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">I appreciate all help I can get.</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US"> </span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">Kind regards,</span></div><div style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:New serif;" class="ydpb5e28434yiv8546746782"><span class="ydpb5e28434yiv8546746782" lang="EN-US">Paul Malm<span class="ydpb5e28434yiv8546746782Apple-converted-space"> </span></span></div></div></div></blockquote></div><br class="ydpb5e28434yiv8546746782"></div></div></div>_______________________________________________<br>postgis-users mailing list<br><a 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