6
votes
1answer
98 views

How to get the centroid of a set of points in POSTGIS?

I use PostgreSQL with POSTGIS extension. I have a set of points in the_geom column from a table myshema.myobjects I would want create a select statement to get the centroid of this cluster, so from a ...
0
votes
1answer
51 views

Self organizing maps with Postgis

I am trying to plot hot regions. It's reorganizing mapping We have a table "product" with three attributes : lat log n_items: number of items that we sell I'd like to group point in one polygon ...
1
vote
1answer
101 views

How to cluster similar lines in PostGIS?

In PostGIS I have a large database of linestrings which I have obtained using ST_makeline function. I would like to cluster similar lines based on where the lines start and end. Here is an example ...
3
votes
2answers
222 views

How can I GROUP BY linear spatial clusters with PostGIS?

I have a series of points in a horizontal line, arranged into discrete spatial clusters by the underlying data pattern. Here's an example of what they look like: How can I use PostGIS to group them ...
4
votes
2answers
262 views

clustering points in postgresql to create contour map

UPDATE: To try to make this a little more simple, is it possible to create a query which selects a group of points such that each point in the group is at most X units away from at least one other ...
2
votes
0answers
105 views

Installing knn on PostgreSQL for windows

I am trying to install the extension KNN for clustering as an extension on my PostgreSQL database. I have downloaded the file http://www.pgxn.org/tag/analysis I found instructions on how to ...
1
vote
1answer
3k views

Google Maps MarkerClusterer - Remove all clusters

So, I have a PostGreSQL DB with 317 datapoints - all spatially enabled through PostGIS. I have queried this using PHP as GeoJSON and overlaid it on Google Maps (using a converting routine). I have ...
40
votes
3answers
11k views

Spatial clustering with PostGIS

I'm looking for spatial clustering algorithm for using it within PostGIS-enabled database for point features. I'm going to write plpgsql function that takes distance between points within the same ...