Questions tagged [clustering]

Partitioning data points into subsets of objects according to their mutual "similarity," without using preexisting knowledge such as class labels.

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97
votes
7answers
43k 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 ...
34
votes
7answers
35k views

Clustering spatial data in R? [closed]

I have bunch of data points with latitude and longitude. I want to use R to cluster them based on their distance. I have already taken a look at this page and tried clustTool package. But I am not ...
34
votes
5answers
15k views

Identifying clusters in vector point data using QGIS?

I have a vector dataset of rural broadband data-points (how fast, etc.) and I'd like to explore if there are clusters of points with similar characteristics, and to plot polygons encompassing them. ...
30
votes
9answers
16k views

Creating polyline-based “heatmap” from GPS tracks?

This winter I am planning to track my downhill skiing/snowboarding using a GPS. Most of my riding will occur at the same resort. I would like to be able to create a sort of "heatmap" that shows the ...
24
votes
1answer
3k views

Seeking tools for regionalization/redistricting?

I am looking for tools for regionalization / districting in GIS. So far I have been able to identify Districting ArcGIS extension (now also online) REDCAP (currently limited to 50k input polygons) ...
23
votes
1answer
2k views

Clustering of multiple raster layers to create sub-regions using QGIS?

I'm attempting to create n sub-regions from a polygon based on a cluster analysis of a bunch of overlapping raster layers (physical layers, eg: depth, currents, waves). Currently, I can create a ...
20
votes
4answers
4k views

How can I generate irregular grid containing minimum n points?

Given a large (~ 1 million) sample of unevenly distributed points - is it possible to generate irregular grid (in size, but could also be irregular in shape if that is possible?) that will contain ...
19
votes
6answers
19k views

How to Create Animated Cluster Markers in OpenLayers/Leaflet?

I want to use Leaflet due to the smooth transitions which Openlayers seems like they can't match. I specifically require the ability to cluster markers with custom styled marker groups. The best ...
19
votes
1answer
853 views

QGIS 3.0 point cluster renderer, is it possible to control rendering order (z-order)?

I've been having a play with the new point cluster renderer in QGIS 3.0.2 and it's great - a lot easier (and faster) than having to do the clustering yourself. To show what I mean, here's an example ...
16
votes
3answers
917 views

Clustering undirected lines

I'm looking for an efficient way to cluster lines independent of their direction. That means that a line between New York and Los Angeles should be in the same cluster as a line in the other direction ...
15
votes
3answers
3k views

Visualising clustered features in web maps?

I'm looking for the best symbol to display clustered features in the ArcGIS Server JS API. I don't like the "fly-out" animated cluster symbol, as used in the Silverlight API clustering or the JS ...
14
votes
3answers
1k views

Determining if trees within forest gaps are clustered using R?

The attached dataset shows approximately 6000 saplings in approximately 50 variable sized forest gaps. I am interested in learning how these saplings are growing within their respective gaps (i.e. ...
14
votes
5answers
17k views

Clustering trajectories (GPS data of (x,y) points) and mining the data

I've got 2 questions on analyzing a GPS dataset. 1) Extracting trajectories I have a huge database of recorded GPS coordinates of the form (latitude, longitude, date-time). According to date-time ...
13
votes
1answer
5k views

Clustering geographical data based on point location and associated point values

Given data points with longitude, latitude, and a third property value of this point. How can I cluster points into groups (geographical sub-regions) based on the property value? I searched by google ...
12
votes
4answers
9k views

Finding Clusters of N Points Within X Distance using ArcGIS Desktop?

We have tried two methods of cluster analysis: Cluster and Outlier Hot Spot ... but neither meets our specification which has these 3 parameters: a Set of Point features N points within a Cluster X ...
11
votes
2answers
337 views

Identify points in a shapefile that have no other point within x km with QGIS

This is probably a naive question but I am struggling as a new user to QGIS. I have a very large shapefile (275,000 points, but can break this into about 10 subregions if necessary for faster ...
11
votes
1answer
504 views

Spatial analysis and clustering near features

Im working on marking behaviour in group living animals and im interested in how marking behaviour is affected by certain characteristics of the neighbouring groups. I have plotted the territories of ...
11
votes
1answer
999 views

Creating groups of points from lat/long pairs using R?

I have a database which contains Lat/Long pairs to identify the location of points of interest. I would like to group the points of interest into groups of 10. The group should be geographically ...
10
votes
4answers
1k views

Finding clusters of one set of points around another set of points from different layer?

I want to see if there is clustering of a certain type of buildings (x) around another type of buildings (y). The two point files are in different layers. I cannot figure out which tool I would ...
10
votes
3answers
2k views

How to cluster points based on a kernel density?

I have a large dataset with 36k points representing commercial land uses, each with a field containing the square footage. I have run a kernel density analysis on this dataset, producing a raster ...
10
votes
1answer
730 views

Generating urban footprint polygons from building clusters in QGIS?

I'm not sure what the correct term is, but it's a common cartographic design pattern. I want to show the outline of built-up areas as a filled polygon beneath road and buildings layers. In ...
10
votes
1answer
2k views

Birch algorithm does not cluster as expected

I'm using Birch algorithm from scipy-learn Python package for clustering a set of points in one small city in sets of 10. I use following code: no = len(list_of_points)/10 brc = Birch(...
10
votes
2answers
5k views

How do I group near points with GPS positions?

I'm an IT person so I don't know too much about projections and so on, I hope you can help me. I have made an application for Android that collects a GPS position, so I have the latitude and the ...
10
votes
1answer
296 views

Stratified OpenLayers Clustering

I have an OpenLayers map with point clustering, but I want to apply a much finer granularity to the data represented in the map. Specifically, I want to stratify the clusters according to an ...
9
votes
1answer
4k views

Grouping map points into fixed cluster sizes?

I have a dataset of 655 lat/long pairs which I'd like to split into about 100 groups. A group should have 5-10 pairs which are geographically close to each other. Dense groups should have more ...
9
votes
2answers
4k views

Spatial statistics tools : clustering analysis on raster data

I've an apparently simple problem, but i can't find a clear methodology to use. I'm tasked to delimit "urban areas" by vector convex polygons, using the Gridded Population of the World dataset from ...
9
votes
1answer
126 views

Natural neighborhoods terminology

Sometimes the hardest part of an analysis is knowing what something is called. What are some R packages, but more importantly, terminology I should be searching for to define contiguous city ...
9
votes
1answer
2k views

Compare spatial cluster/agglomeration patterns for polygon data

I have agricultural data in form of polygons which I would like to test for spatial clusterings/spatial agglomerations. All in all I have about 40 variables which I can aggregate and standardize in ...
8
votes
5answers
4k views

Algorithm to find polygons enclosing points

I'm trying to find an algorithm that can determine the smallest possible polygons to cover a number of points. I know how to get the convex hull around all the points, but say that the points are ...
8
votes
3answers
3k views

Remove clumps of pixels in R

I would like to remove isolated pixels (or clumps of pixels <9) from my raster image. library(raster) # create some raster data r <- raster(ncols=12, nrows=12) set.seed(0) r[] <- round(runif(...
8
votes
1answer
6k views

Using Drop Markers and MarkerClusterer together?

I want to create a rather visually appealing representation of time-series data (Costco Store Locations w/ opening dates). My idea was to plot them on a map, in time-series, but it seems that the ...
8
votes
2answers
8k views

How to cluster Google Maps kml overlay

I have several thousand markers stored in a kmz file that I load into a Google Maps (v3 API). I've looked around to find a way to cluster the overlay data, but to no avail. MarkerClusterer looks nice,...
8
votes
1answer
2k views

Appropriate distance metric for spatial clustering of geographic coordinates

I have a set of locations in geographic coordinates, and I would like to group the points using hierarchical clustering followed by tree-cutting at various "heights" in order to calculate group-wise ...
8
votes
2answers
3k views

Incremental spatial clustering algorithm

I'm in search of a incremental spatial clustering algorithm. Here is my use case: users create entries with an initial position users may change the positions of existing entries I now want to ...
8
votes
2answers
965 views

What are my options for Server side clustering using open source GIS tools?

I need to make a webapp that will show over 40K Points on a map. These points are all across the globe. Using WFS Service and OpenLayers, it is possible to do clustering on small set of points, but ...
7
votes
1answer
9k views

Grouping points in QGIS?

I need to group 400 points in 10 groups with 40 points each. The goal is to get the 40 points geographicly together like this: Any idea how to do this with QGIS?
7
votes
6answers
8k views

How do I cluster XY point data? (ArcGIS 9.3)

I have a whole bunch of icons displaying on a map, I want these clustered together as was suggested to me for a different question here... ArcGIS 9.3. How do I increase Picture Marker Symbol ...
7
votes
2answers
3k views

How can I cluster all points in a postgis table together based on their distance from each other?

I have a PostGIS (in postgres 9.3) table which has Points. I want to figure out the "clusters" in the data. If 2 points are < X distance apart, they should be added to a cluster, and this should be ...
7
votes
1answer
6k views

Clustering points/polygons based on proximity (within specifed distance) using QGIS?

I have seen similar questions asked about grouping points and Concave Hull being given as an answer, but in my case there are no "features"/attributes that will classify the points. The only parameter ...
7
votes
2answers
1k views

Open layers supercluster integration - is it possible to fetch underlying features for each cluster?

I am using the open layers 3 with supercluster at the moment, extending the example provided here : https://jsfiddle.net/d5gwvz2y/2/ My question is: How does one fetch all the underlying features ...
7
votes
1answer
7k views

Finding clusters of points based distance rule using R? [duplicate]

I have some points that I need to divide into groups based on clusters of points: x <- c(-1.482156, -1.482318, -1.482129, -1.482880, -1.485735, -1.485770, -1.485913, -1.484275, -1.485866) y <- ...
7
votes
2answers
2k views

How to cluster points of interest by lat lon for my WP7 app?

I have alread asked this question on SO, so I apologize if duplicating this is bad form. I will link to each of the sites if I get the right answer. I have a collection of my own PointOfInterest ...
7
votes
1answer
284 views

Clustering points and summing up attributes per cluster in QGIS

We want to find out the ideal location for sheds and the required dimensions of each shed. As input, we have a point layer with locations (each representing one arable field) and the estimated yield ...
7
votes
1answer
245 views

Finding largest number of observations within a given radius

I have the following problem: Given the location of insured properties (say houses with fire insurance), i have to find the largest sum of insured values which fit into a 300m radius. Now, my first ...
7
votes
2answers
668 views

Hot Spot Analysis using ArcGIS for Desktop?

I have a point shape containing locations of cars and a line shape containing roads. Now I want to identify hotspots/clusters. I want to find hot spots where for example the speed of the cars is ...
7
votes
3answers
611 views

How to compare spatial patterns (crime cases vs population)?

I am looking for a way to statistically compare two spatial patterns in shape polygon data (not point pattern analysis). Let's say I have a city map divided in neighborhoods (barrios), in shape ...
7
votes
1answer
221 views

Categorising Point Clusters

I have a point dataset of solar farm locations. The points are grouped according to which substation they feed into (see below). I would like to test the hypothesis that electrical output ...
7
votes
1answer
516 views

Generate clusters of X points within N meters

I have a set of roughly 4,000 points in very close proximity and I need to generate clusters of 5 points, with each point no farther than 50 meters from the (mean?) center of the cluster. I've ...
7
votes
1answer
598 views

Finding density centroids within polygons in PostGIS

I want to find the highest density of OpenStreetMap nodes within a dataset of census geometries. I want to tie the census data to the location of the node which is most central in terms of population. ...
7
votes
2answers
2k views

creating clusters of points with same attributes

I have a file of some 4000 points, which belong to around 400 different categories (species of rare plants). I would like to remove duplicates within the categories (which could be repeated ...