[GRASS-dev] How to calculate mean coordinates from big point datasets?

Markus Metz markus.metz.giswork at gmail.com
Wed Sep 25 01:37:08 PDT 2013


Glynn Clements wrote:
>
> Markus Metz wrote:
>
>> Please try the new addon v.centerpoint [0]. It calculates various
>> center points for point clouds, lines, and areas. Standard options are
>> the geometric mean (center of gravity)
>
> That's the arithmetic mean.
>
> The geometric mean of a set of N values is the Nth root of the product
> of the values (i.e. the logarithm of the geometric mean is the
> arithmetic mean of the logarithms of the values). It wouldn't be
> meaningful to compute the geometric mean of coordinate data.

Right, I fixed the documentation. Internally, the arithmetic mean has
been used already to calculate centers of gravity.

Markus M


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