[gdal-dev] Vector area calculation

[ky]

Hi Even,

Thank's so much for your help! Indeed with this option it yields the
expected result :

Area ha farm: 6.0
Area ha calculated (gdal): 6.0
Area ha calculated (geopandas): 6.0



On Fri, Jan 10, 2025 at 1:52 PM Even Rouault <even.rouault at spatialys.com>
wrote:

> Hi,
>
> I suspect you are running into
> https://gdal.org/en/stable/tutorials/osr_api_tut.html#crs-and-axis-order
>
> Concretely try adding:
>
> source_srs.SetAxisMappingStrategy(osr.OAMS_TRADITIONAL_GIS_ORDER)
>
> at line 34.
>
> Even
>
>
> Le 10/01/2025 à 17:49, ky via gdal-dev a écrit :
>
> Hello all, hope you are well
>
> Got some unexpected results computing area using GDAL==3.4.1 and official
> Brazilian projection, where results are about half of what is reported as
> correct. Does anyone knows what is causing it ?
>
> Just to compare shapely/geopandas yields correct results using same
> projections.
>
> code can be found on this gist:
> https://gist.github.com/rupestre-campos/a82a1403cb47a8153f07c775d7902f50
>
> the linked scrip outputs
> Area ha farm: 6.0
> Area ha calculated (gdal): 3.23
> Area ha calculated (geopandas): 6.0
>
>
>
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>
> -- http://www.spatialys.com
> My software is free, but my time generally not.
> Butcher of all kinds of standards, open or closed formats. At the end, this is just about bytes.
>
>
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