<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body dir="auto"><div dir="auto">Hi Maria.</div><div dir="auto">The symbology does not reclassify the underlying raster, it just changes the way it is displayed. Use the raster calculator to generate a new raster with the Classes you require. The native qgis calculator works well. You can find it in the upper word menu under raster. Once you have your raster reclassified, you can then convert it to a vector format </div><div dir="auto"><br></div><div dir="auto">Kirk Schmidt</div><div dir="auto"><br></div><div dir="auto"><br></div><div dir="auto"><br></div><div id="composer_signature" dir="auto"><div style="font-size:85%;color:#575757" dir="auto">Sent from my Galaxy</div></div><div dir="auto"><br></div><div><br></div><div align="left" dir="auto" style="font-size:100%;color:#000000"><div>-------- Original message --------</div><div>From: "Shinoto, PD Dr. Maria via Qgis-user" <qgis-user@lists.osgeo.org> </div><div>Date: 2022-03-29 6:32 p.m. (GMT-04:00) </div><div>To: qgis forum <qgis-user@lists.osgeo.org> </div><div>Subject: [Qgis-user] creating vector layer from slope map with few classes </div><div><br></div></div>Hi, <br><br>I have created a slope map from a DTM. <br><br>I have limited the symbology to three meaningful classes and wish to create a vector layer with polygons of three classes from that. The conditions are One-Channel-Pseudocolor, Channel1 (Gray), interpolation discrete, modus "fortlaufend" -- not identical interval or quantile, 3 classes with values <=20, 20 - 40, > 40. <br><br>The classes show up in the layer design panel symbology tab, but the layer browser still (thankfully!) shows the greyscale ramp. <br><br>I wish to create a vector layer with polygons from the 3 classes. <br><br>All solutions I have looked up work under slightly different condition. After all I do not know how to get the data of the DTM into three classes like "Flat-Gentle-Steep"; I think the vectorization should work easily then. <br><br>Can anybody hint me to a solution?<br><br><br>Thanks and best wishes, <br>Maria<br>_______________________________________________<br>Qgis-user mailing list<br>Qgis-user@lists.osgeo.org<br>List info: https://lists.osgeo.org/mailman/listinfo/qgis-user<br>Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user<br><br></body></html>