[Qgis-user] How set real origin on a false origin dataset

[Lens Paul]

Hi Andrea,

False origins happens often with local topographical surveys, with also
a false altitude origin. Architectural plans are sometimes even more
tricky: rotated, or with a centimetric or millimetric scale instead of a
metric scale. A way is to transform the data with a CAD software when
available. Even then, problems can arise e.g. when rescaling some objects.

I suppose a workaround in your case  would be to use the "move" command
and to snap to a point drawn at the correct coordinates. This could be
cumbersome when there are many layers to edit, which is often the case,
unless you import the dxf as a unique layer....

If your data consist merely of point data (no polylines), it should be
possible, after conversion of the dxf in a shapefile, to create the  X,
Y attributes using the field calculator, and to recalculate these
attributes with the same tool.

In the case of polylines, there is the possibility to extract vertices.
But I do not know if there is a possibility to recreate the polylines
after the recalculation of the X, Y attributes.

Dxf conversion is a complicated subject. The evolution of the
capabilities of QGIS in that field is amazing. Many thanks to the
developers for that.

Hope this helps,

Paul

Le 13/11/2019 à 14:04, Andrea Peri a écrit :
> Hi,
> We have a dxf containings geograph data in false.origin .
> I'm searching a solution to put a kind of origin (x,y) to sum to every
> point of the data. Is possible to set an origin.to <http://origin.to>
> a dataset in qgis ?
>
> Thx.
> Andrea.
>
>
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