#1373 closed bug (duplicate)
Derived area values from identify tool differ from calculated PostGIS area
| Reported by: | hdus | Owned by: | nobody |
|---|---|---|---|
| Priority: | major: does not work as expected | Milestone: | |
| Component: | Vectors | Version: | Trunk |
| Keywords: | Cc: | ||
| Must Fix for Release: | Yes | Platform: | RedHat |
| Platform Version: | Awaiting user input: | no |
Description
When I identify a polygon with the identify tool, the derived area differs from the calculated area with postgis area(the_geom) function. The difference is small but existing:
QGIS: 15.516 km2
PostGIS: 15.525 km2
Change History (4)
comment:1 by , 16 years ago
| Component: | Build/Install → Vectors |
|---|
comment:2 by , 16 years ago
comment:3 by , 16 years ago
| Resolution: | → duplicate |
|---|---|
| Status: | new → closed |
Already reported with #1219
Note:
See TracTickets
for help on using tickets.
Replying to hdus:
If you are using On-the-fly transformation, the difference is because QGIS uses calculation on an ellipsoid rather than plane calculations as PostGIS uses for area().
Without OTF, QGIS uses plane calculations also, but there may still be a very small difference.
This is essentially the same problem as I put in #1219.