Hi Lucas,

ST_Transform in Sedona follows lat/lon order while GeoPandas might be using
lon/lat order.

 Can you try to swap the lat/lon order in your Sedona geometry and see if
it works? To swap the order, please use Sedona ST_FlipCoordinates

Thanks,
Jia

On Wed, May 31, 2023 at 1:29 PM Lucas Gomes de Oliveira Corbanez - LCB <
[email protected]> wrote:

> Hello!
>
> I am currently working on a test that involves calculating the area of a
> circumference with a radius of 0.001 degrees -created via buffer-, centered
> at latitude -4 and longitude -63. The test geometry is on geographical
> coordinates (EPSG:4326). To obtain precise measurements in “ha”, I convert
> the data into two coordinate systems: UTM 20S (EPSG:31980) and WGS 84
> (EPSG:3857).
>
>
>
> To perform these calculations, I utilized GeoPandas and Apache Sedona, but
> I encountered a significant discrepancy in the results obtained from the
> two libraries. The area calculations conducted with GeoPandas yielded the
> following results:
>
>
>
> area_3857_gpd: 3.9019353 ha
>
>
>
> area_utm_gpd: 3.85412083 ha
>
>
>
> However, when I employed Apache Sedona to perform the same calculations,
> the results differed significantly:
>
>
>
> area_utm_sedona: 2.07367218 ha
>
>
>
> area_3857_sedona: 8.573814622 ha
>
>
>
> Additionally, I have cross-validated the results obtained with GeoPandas
> by performing the same area calculations using QGIS. The results obtained
> with GeoPandas match those obtained from QGIS. Hence, the issue seems to
> lie specifically with the Apache Sedona library.
>
>
>
> I would appreciate any insights or suggestions that could help me
> understand the cause of this discrepancy between GeoPandas and Apache
> Sedona. Are there any known differences or considerations when using these
> libraries for area calculations?
>
>
>
> Best regards,
>
>
>
> *Lucas Corbanez*
> [email protected]
> Consulting Services - Analytics
> Tel: +55 (11) 2306-8165
> www.iteris.com.br
>
>
>
>
>
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