On Wed, 5 Dec 2018 at 01:40, C Hamilton <[email protected]> wrote: > > I have been writing some code that maintains the Z dimension for vector > layers. When I create a layer from QGIS points whether it is a point or line > layer and I create the points with QgsPoint(x, y, altitude), I can do this > without using PointZ or LineStringZ layers and it maintains the Z axis. > > What is the purpose of PointZ, LineStringZ, and PolygonZ? Is there a reason I > should be using them when Point, LineString, and Polygon seem to work the > same? Is there a reason I should not use the Z versions?
This depends. I gather you mean that you can freely create geometries with z or m dimension, regardless of whether the layer itself has these dimensions? If so, it depends on the underlying layer type. Some are more fussy then others, but some, (eg memory layers) will happily accept any dimensionality without complaining. This *can* cause issues when later converting these layers to other formats though, so it's always best to correctly define the dimensionality of your layer upfront. Nyall > > Thanks, > > Calvin > _______________________________________________ > Qgis-user mailing list > [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user _______________________________________________ Qgis-user mailing list [email protected] List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
