[Qgis-developer] Processing params always n meters?

[Paolo Cavallini]

Hi Raymond,

Il 05/03/2017 09:15, Raymond Nijssen ha scritto:

> I've been thinking of this as well and I would love it! I hate ending up
> with a huge circle on my screen after performing a quick "look how easy
> qgis processing is!" 500 degrees buffer on my data. :)

Yeah, exactly my case :)

> The problem is that you cannot convert degrees to meters so easily since
> they depend on the location on earth. I'm sure you know.

Wouldn't it make sense to treat the distance as a segment, and reproject
that? As for the XY difference you mention, we could take the best
approximation by assuming that the distance segment is diagonal, and
warn the user about lack of precision.

> 1. Automatically reproject the data to the appropriate CRS (?), perform
> the analysis, and reproject back. UTM could be used for it, hoping all
> data is in a single zone.

This can be quite costly.

Thanks for the feedback.

-- 
Paolo Cavallini - www.faunalia.eu
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