[Qgis-user] calculate areas of polygons imported from a dxf file

[Zoltán Siki]

Dear Jose,

I think you imported a line layer from the DXF file which has no area.
Convert the line layer to polygon one using Vector/Geometry tools/Lines to
Polygons from the menu.

Regards,
Zoltan


Jose Sanchez via QGIS-User <qgis-user at lists.osgeo.org> ezt írta (időpont:
2024. márc. 23., Szo, 19:30):

> Hi,
>
>
>
> I added a vector layer to QGIS 3.36.0 by importing a dxf file (it contains
> two polygons). I want to calculate the differentce in área of the polygons
> (considering the topography of a DEM file visualized in hillshade). So, I
> opened the attribute table, created a calculated field (ANRio)  with the
> $area expression, but I get a NULL value. I see that my attribute table has
> NULL values for Paper Space and Line Type (I do not know if that might be
> the problem). I am probably not importing the polygons properly. I also
> tried importing as shape file using “anotherDXFimport” plugin but still I
> get NULL values in the area calculated field.
>
>
>
> I would appreciate your help.
>
>
>
> Thanks,
>
>
>
> Jose
>
>
>
> Imported polygons
>
> [image: Mapa Descripción generada automáticamente]
>
>
>
> Attribute tables
>
> [image: Interfaz de usuario gráfica, Aplicación Descripción generada
> automáticamente]
>
>
>
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>
>
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