[Qgis-user] Can the point displacement center symbol be scaled based on number of corresponding points?

[kimaidou]

Hi all

Since PostGIS 2.2, you can now do the clustering server-side. See [1]
It is not as simple as using a QGIS code feature, and it is only available
for PostGIS layers, but it could do the job. You will probably need to play
with other methods such as ST_Centroid for getting a point and other
aggregates function to count the features involved.

[1] http://postgis.net/docs/manual-2.2/ST_ClusterWithin.html

Cheers,
Michaël

2015-11-12 10:30 GMT+01:00 Neumann, Andreas <a.neumann at carto.net>:

> Hi,
>
> On 2015-11-12 10:22, Anita Graser wrote:
>
>
> On Nov 12, 2015 9:11 AM, "Neumann, Andreas" <a.neumann at carto.net> wrote:
> >
> > I also think that - what Anita wants - is a special case of a cluster
> renderer (one that actually does not cluster, but only count how many
> features are at the same geometry). To have this as a special option of the
> displacement renderer would be a quite misleading ...
> >
> > But the cluster renderer also allows for a search radius (similar to the
> heatmap) - while the displacement renderer only looks at features at the
> exact same location (I know there is now a tolerance, but this was only
> added later).
>
> Exactly this tolerance makes the renderer much more interesting to me.
> Never had a use case for the original displacement renderer.
>
> but still we shouldn't misuse terms. Displacement is the opposite of
> clustering. What you want is clustering, not displacement.
>
> Andreas
>
>
>
>
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