averaged center of cluster

[marimil]

Please implement the calculation of coordinates of the marker cluster as the average of the coordinates of the markers that belong to the cluster.

In this example http://z-lowicza.pl/mapy/c is drawn incorrectly.

[ideak]

Hi, thanks for pointing this out. Yes, this is a known limitation due to the simple way how cluster centers are calculated at the moment. The center will be the position of the first marker added to the cluster. Since this first marker will depend on the current zoom level (which determines the view boundaries and the visible markers), it's somewhat random how clusters are formed in different zoom levels. Also there can be different definitions of "center". One close to intuition would be one calculated with some weighted algorithm which would put the center in the densest spot. But at the moment this again is not so, the center will be just the very first marker the script encounters that can't be put in a pre-existing cluster and so will create a new cluster.

The solution I was thinking of is to pre-calculate the clusters per zoom level, but I haven't yet gotten down to the details of how to implement it.

[marimil]

In this code
google-maps-utility-library-v3.googlecode.com/svn/trunk/markerclusterer/src/markerclusterer.js
averageCenter variable is implemented. Maybe this will help.
Link to the example:
google-maps-utility-library-v3.googlecode.com/svn/trunk/markerclusterer/examples/advanced_example.html
Sometimes, however, markers disappear.

[ideak]

marimil: thanks, I will look at that implementation, try to track down the bug you mentioned and port it. If you can help patches are welcome! :)