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So, first of all, here is a test file: https://we.tl/t-xqo5KyRlqD

The column length was added using QGIS (v 3.10 A Coruña), field calculator and adding parameter $length.

If the file is opened with geopandas (v 0.6.1), the property length outputs this:

a.length Out[8]: 0 1581.729679 1 899.177689 2 38.054220 3 47.333848 4 189.591771 5 275.946388 dtype: float64

the values obtained by qgis are:

a['length'] Out[9]: 0 1580.830737 1 898.686067 2 38.033291 3 47.307854 4 189.489982 5 275.796306 Name: length, dtype: float64

As you can see there is a difference of a few centimeters.

Has anyone else experienced this?

Kadir Şahbaz
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ImanolUr
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1 Answers1

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Yes both are correct. The difference is because one it taking into account the curvature of the earth while the other is not.

See following images:enter image description here

and enter image description here

nickves
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  • I know the difference between one an another, I did not think that QGIS was providing elipsoidal and GeoPandas cartesian. Thank you! – ImanolUr Feb 19 '20 at 09:38