Bug report #3244
AddGeometry- faulty units and precision
|Affected QGIS version:||Regression?:||No|
|Operating System:||Debian||Easy fix?:||No|
|Pull Request or Patch supplied:||Resolution:||invalid|
|Crashes QGIS or corrupts data:||Copied to github as #:||13304|
Using Tools>GeometryTools>Export/AddGeometryColumns, has some problems with units and precision.
Output seems to be in units of 100km eg
An area 69.38Ha (measured using the measurement tool) is output as 6.9e-05
Perimeter ~ 3.3Km (measured using the measurement tool) is output as .032753
This has the potential to cause errors and produce misleading information on subsequent calculations
Project units are m.
Sample files before and after Add Geometry are attached
Workaround is at: http://forum.qgis.org/viewtopic.php?f=2&t=7531#p15730
#1 Updated by cfarmer - about 12 years ago
- Resolution set to invalid
- Status changed from Open to Closed
The attached shapefile is not in a projected coordinate system, so measuring area and perimeter does not really make sense. As mentioned in the forum thread linked to this ticket, you will need to reproject your data to a projected coordinate system that supports measuring areas. This tool does not use the project CRS, and for good reason: it outputs the area and perimeter as attributes of a layer, so while the project properties may vary from project to project, the layer itself does not.
I am going to close this as 'invalid'. If you feel that this should not be the case, please feel free to reopen the ticket.