<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Aug 24, 2020, at 9:34 AM, Evert Etienne <<a href="mailto:evert.etienne@gmail.com" class="">evert.etienne@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Dear all,<br class=""><br class="">I have a question about some behaviour I don’t understand when using PDAL.<br class="">We are in the middle up updating PDAL from 1.8.0 to 2.1.0. We have some unit tests checking the spatial reference system reading in our code.<br class="">In 1.8.0, the spatial reference read (using info—metadata `spatialreference`) from a test pointcloud (<a href="https://pdal.io/tutorial/reading.html#a-basic-inquiry-example" class="">https://pdal.io/tutorial/reading.html#a-basic-inquiry-example</a> interesting.las) was the following<br class=""><br class="">'PROJCS["NAD_1983_Oregon_Statewide_Lambert_Feet_Intl",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137,298.257222101]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433]],PROJECTION["Lambert_Conformal_Conic_2SP"],PARAMETER["standard_parallel_1",43],PARAMETER["standard_parallel_2",45.5],PARAMETER["latitude_of_origin",41.75],PARAMETER["central_meridian",-120.5],PARAMETER["false_easting",400000],PARAMETER["false_northing",0],UNIT["foot",0.3048,AUTHORITY["EPSG","9002"]]]’<br class=""><br class="">But using 2.1.0, this becomes the following<br class=""><br class="">'PROJCS["NAD_1983_Oregon_Statewide_Lambert_Feet_Intl",GEOGCS["GCS_North_American_1983",DATUM["North_American_Datum_1983",SPHEROID["GRS_1980",6378137,298.257222101]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]]],PROJECTION["Lambert_Conformal_Conic_2SP"],PARAMETER["latitude_of_origin",41.75],PARAMETER["central_meridian",-120.5],PARAMETER["standard_parallel_1",43],PARAMETER["standard_parallel_2",45.5],PARAMETER["false_easting",400000],PARAMETER["false_northing",0],UNIT["foot",0.3048,AUTHORITY["EPSG","9002"]],AXIS["Easting",EAST],AXIS["Northing",NORTH]]’<br class=""><br class="">I am lost on 2 topics<br class="">- How can a read operation change the data returned, is there some lookup being done (proj version causing this?)<br class=""></div></div></blockquote><div><br class=""></div><div>Yes. First confirm that the same version of PROJ and GDAL are being used between these two different WKT.</div><br class=""><blockquote type="cite" class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">- Are these 2 equivalent or what causes this to change and be different?<br class=""></div></div></blockquote><div><br class=""></div><div>It looks to me by a quick glance at the parameters that these are equivalent, but it is totally possible that PROJ produces "equivalent" WKT that do not string-compare as equal.</div><br class=""><blockquote type="cite" class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Very possibly i am missing some crucial background information on these spatial references, so feel free to point me to relevant documentation or changelogs.<br class=""></div></div></blockquote></div><br class=""><div class="">Dealing with WKT is akin to enduring the cruciatus curse...</div><div class=""><br class=""></div><div class="">Howard</div></body></html>