Bug report #11861
$area calculation
| Status: | Closed | ||
|---|---|---|---|
| Priority: | High | ||
| Assignee: | - | ||
| Category: | Vectors | ||
| Affected QGIS version: | 2.6.0 | Regression?: | No |
| Operating System: | Easy fix?: | No | |
| Pull Request or Patch supplied: | No | Resolution: | invalid |
| Crashes QGIS or corrupts data: | No | Copied to github as #: | 20076 |
Description
Goodmorning,
in qgis 2.6 the $area calculation from field calculator returns errors for every record: it returns always -92.2337203685478 sq_mt. The layer was created with qgis 2.4 and i work in EPSG 32632.
In qgis 2.4 it was ok.
Arcgis calculates the right value.
If i use "vector/geometry tools/export_add geometry columns" it stops at 87% of elaboration.
Thank you
Lorenzo
History
#1
Updated by Giovanni Manghi almost 10 years ago
- Assignee deleted (
Giovanni Manghi) - Category changed from Attribute table to Vectors
- Status changed from Open to Feedback
please attach the vector.
#2
Updated by lorenzo pote almost 10 years ago
- File BOSCHI__area_error.zip added
here the shp file. I've the same error with all layer.
lorenzo potè
#3
Updated by lorenzo pote almost 10 years ago
- File BOSCHI__area_error.zip added
here the shp file. I've the same error with all layer.
lorenzo potè
#4
Updated by Giovanni Manghi almost 10 years ago
- Resolution set to invalid
- Status changed from Feedback to Closed
The "AREA" field in the shape you attached is of type double with length 19 with 16 of those spaces for the decimal part. This means that in this column you can only accommodate numbers with 2 integer numbers. If you calculate the area in hectares ($area/10000) you will see that the values are ok because the numbers are small enough to be stored there. If compute the area in sq m then you see strange values: this behavior can be improved but it has an explanation.
If you compute the area in new columns (with the proper length) there are no problems.