On Sun, Aug 1, 2010 at 13:54, Volker Mische <[email protected]> wrote: > On 01.08.2010 22:48, J Chris Anderson wrote: >> >> On Aug 1, 2010, at 1:43 PM, Volker Mische wrote: >> >>> On 01.08.2010 17:24, Benoit Chesneau wrote: >>>> >>>> On Sun, Aug 1, 2010 at 2:17 PM, Volker Mische<[email protected]> >>>> wrote: >>>>> >>>>> On 01.08.2010 10:53, Benoit Chesneau wrote: >>>>>> >>>>>> I'm looking for a way to limit number of points retrieved for an area >>>>>> depending on its size. Ie When playing with the zoom on the map I want >>>>>> to be able to only display and retrieved only main points instead of >>>>>> all the points in this area. Is there a simple way to do that actually >>>>>> ? >>>>>> >>>>>> - benoit >>>>> >>>>> Hi Benoit, >>>>> >>>>> there a two ways. Either introducing a "limit" parameter, but that's >>>>> probably not what you want. It would limit to a arbitrary selection >>>>> (not the >>>>> "main points" as you'd like to have it). >>>>> You probably want clusters. My suggestion is to do it on the client >>>>> side >>>>> with OpenLayers' cluster strategy [1][2]. >>>>> >>>>> [1] http://openlayers.org/dev/examples/strategy-cluster.html >>>>> [2] http://openlayers.org/dev/examples/strategy-cluster-threshold.html >>>>> >>>>> Cheers, >>>>> Volker >>>>> >>>> This solution doesn't work when you have a lot of points though. Do >>>> you plan to add such things to geocouch ? >>>> >>> >>> Clustering isn't that easy. I think some layer on top of GeoCouch >>> should/will be built to handle such things. It can even be in any >>> programming language and communicate with GeoCouch via HTTP. >>> >> >> If there is a threshold that can be emitted with the points, maybe a _list >> function is the way to filter it server side. >> > > The problem is, that the points are potentially returned in random order. So > you never know if there will be a point that is close to anther one at a > later stage.
I think Chris was referring to a zoom threshold of sorts, which is independent of nearby points. R
