[mkgmap-dev] nearby-POI: What to do with several POI arranged on a circle?

Thu May 7 09:21:51 BST 2020

Hi

The problem is in the point grouping algo, rather than anything to do
with the merge-at-mid-point option.

Although an interesting problem to solve, it seems to be getting
excessive. The simple logic in the last versions seemed to solve most
users's problems and make them happy.

Ticker

On Thu, 2020-05-07 at 07:42 +0000, Gerd Petermann wrote:
> Hi all,
> 
> while doing further tests I've found this edge case (see attached
> file)
> Draw a circle with a diameter of ~56m and tag all nodes amenity=bank.
> The default style has 
> amenity=bank [0x2f06 resolution 24]
> 
> With --nearby-poi-rules=0x2f06:30:merge-at-mid-point one might expect
> a single POI in the middle of the circle, but the result is
> different:
> Since there is no POI near the center of the circle the current algo
> finds 4 groups, all close to the edge of the circle.
> 
> I think for merge-at-mid-point I need a different algo. I'm looking
> at https://en.wikipedia.org/wiki/Cluster_analysis now.
> 
> Gerd
> 
> 
> 
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