Skip to main content

Questions tagged [clustering]

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

Filter by
Sorted by
Tagged with
1 vote
0 answers
44 views

Grouping data points based on proximity and minimal count of attribute in QGIS

I am using QGIS to map animal counts on farms in the Midwest US and using a circle polygon to show where there are more than 30,000 animals between all the farms in that specific area. Each data point ...
Ryan Whalen's user avatar
4 votes
1 answer
97 views

PostGIS ST_ClusterDBSCAN returns NULL

I have problems with the ST_ClusterDBSCAN function in PostGIS. I try to group points derived from lines with a maximum distance of 15 meters from each other and a minimum cluster size of 4. This ...
mapmap's user avatar
  • 53
0 votes
0 answers
27 views

Testing for joint spatial clustering across multiple variables

I have an analysis that I'm uncertain how to conduct. I have a GeoPandas dataframe that consists of a few hundred sample points (rows) and for each point I have counts of different variables. These ...
clifgray's user avatar
  • 409
0 votes
1 answer
66 views

Leaflet markercluster: getting the zoom level at which a specific marker is no longer clustered?

I'm using Leaflet markercluster in an app. I have an endpoint where a specific marker is selected (eg. ../marker/12); so the maps centers on that marker and displays its popup when the page loads. But ...
gordie's user avatar
  • 274
0 votes
0 answers
28 views

Getting mean coordinates for unique values in large dataset for hierarchical cluster analysis using QGIS

I'm trying to analyse two different groups (species) of animals in the same space that were fitted with GPS collars, to see how the groups interact within their own groups and with the other group. I ...
user242441's user avatar
0 votes
1 answer
107 views

QGIS k-means fails - Loading resulting layers The following layers were not correctly generated

I'm using QGIS 3.22.14. I'm trying to k-means clusters on raster I have. The tool runs but the errors are not loading with the following log and error: Loading grid: C:/Users/tomi/AppData/Local/Temp/5/...
ReutKeller's user avatar
  • 2,169
0 votes
0 answers
20 views

QGIS - Expression for a chart symbology with a clustered layer

I have a layer with buildings that I have clustered and wrapped with a covex hull. Each building has specific information attached. e.g. information about the year of construction. Currently I have ...
Josephine's user avatar
3 votes
0 answers
126 views

Effective points clustering using PostGIS

I want to implement clustering points like here in the last example(with big and small points): https://www.crunchydata.com/blog/postgis-clustering-with-dbscan I have a table in PostgreSQL with ...
hifichevymane's user avatar
0 votes
1 answer
48 views

Are there alternatives to this construction of a minimum spanning tree of a raster for the SKATER algorithm?

This could be seen as a continuation of this question where the top accepted answer uses the spedp library in R in order to generate contiguous clusters of a raster image with multivariate data. In ...
Phil's user avatar
  • 13
1 vote
1 answer
51 views

Creating clusters directly from a GeoJSON APIRest response in OpenLayers?

I am using OpenLayers latest version. Using a APIRest, I fetch a PostGIS endpoint and get a response in GeoJSON format. Then this is used to create a source and a layer : .... const response = await ...
Leehan's user avatar
  • 1,234
0 votes
0 answers
34 views

What data does clustering use from multiple raster files?

I currently have a series of rasters of the same area across different times. The data is categorical: the product of a supervised classification used on LANDSAT data run on ERDAS Imagine. Each ...
Phil's user avatar
  • 13
1 vote
1 answer
77 views

Finding if presences are clustered in presence absence data

I think this is a geographic questions but if not please redirect my question to where it's more suitable. I'm working in R. I have a large dataset (500,00 to 13 million records depending on which ...
Jennifer Taylor's user avatar
6 votes
1 answer
184 views

Differentiating with unique id overlapping/intersecting or isolated convex_hulls in QGIS

From a layer of 2000 points, I have a field with the name 'NUCLEUS' with four categories (1, 2, 3, 4) that identifies each point with a category of density clusters. In red color you can see the ...
Ingrid Ingravida's user avatar
3 votes
0 answers
128 views

How to update a field in a layer with the DBSCAN algorithm using the Graphic Modeler QGIS

As you can see in the screenshots, I have a vector layer 'POINT_LAYER' with an "IDCLUSTER" field ready to be updated. I am also using Graphic Modeler to prepare a processing workflow to ...
Acperience's user avatar
  • 1,142
1 vote
1 answer
50 views

How to add a virtual layer using ST_ClusterDBSCAN function

I have a 'POINTS' layer with 74 points geometry with the fields "NAME" and "ID". I want to add a virtual layer with the following query to calculate the clusters using the DBSCAN ...
Acperience's user avatar
  • 1,142
7 votes
1 answer
134 views

Use algorithm output as expression in QGIS modeler

I want to use the algorithm output within the input expression of another algorithm in the Graphical Modeler of QGIS 3.30.3. Specifically, I want to create clusters of areas previously identified as ...
lesles93's user avatar
0 votes
0 answers
42 views

How to determine the upstream and downstream part of a catchment?

I have around 20 000 topographic depressions in a catchment. I want to perform cluster analysis on them in several round. In a first round, I want to cluster them in two clusters: depressions upstream ...
Lies's user avatar
  • 155
0 votes
0 answers
53 views

Reference article for k-mean clustering on multiple TIFF files

I have multiple TIFF files which represent different variables. some of them are interpolated soil data some of them are satellite imagery, some of them are DEM, Slope, TWI. I used all of them ...
tawhid hossain's user avatar
0 votes
0 answers
228 views

kartoza/geoserver helm chart - Session issue with multiple pods

I'm using kartoza/geoserver image tag: 2.23.0 helm chart v0.3.3 to deploy to EKS cluster. This is my values.yaml file: image: registry: docker.io repository: kartoza/geoserver tag: "2.18.0&...
Aditya Bhuvanraj's user avatar
2 votes
1 answer
112 views

Clustering points by number and accumulation

I'm recently working on a project, where I have a dataset of 450 Points. I need to cluster them into groups of maximum 80 and minimum 60 Points, which should also be located next to each other. By ...
Toby's user avatar
  • 135
1 vote
0 answers
171 views

How to enable the use of the Cluster Analysis plugin

I have installed QGIS version 3.28.11. I have also installed the Cluster Analysis plugin (https://github.com/folini96/Cluster-Analysis-plugin). From the plugin installation window, when I try to ...
emblematica's user avatar
0 votes
0 answers
56 views

Spatial clustering vs sampling

I have a dataset with 100 millions Point (lat/lon). I have started by using GeoHash clustering (applied dynamically by Elasticsearch regarding the user zoom level). I end up with something like that: ...
Klun's user avatar
  • 11
0 votes
0 answers
24 views

Define distance between BORDER points when creating clusters

I need to create clusters based on the certain distance not between core point, but between border points. In other words I need clusters where distance between border point of one cluster to the ...
Roman Sizo's user avatar
2 votes
0 answers
72 views

Availability of clustering function in QGIS development core for Field Calculator tool [closed]

I would like to use Field Calc to calculate the points CLUSTER_ID and update an existing field table. Apart from the Processing Toolbox 'DBSCAN clustering' and 'K-means clustering' applications that ...
emblematica's user avatar
0 votes
1 answer
38 views

Scale by values other than count for a clustered dataset in ArcGIS Online

I have a dataset that is a lot of sales data points for a customer. I created a clustered visualization via AGOL of this. Part of the visualization is that they label by the sum of the sales amounts ...
Tom's user avatar
  • 355
0 votes
0 answers
58 views

Does ST_ClusterKMeans benefit from a spatial index?

Does ST_ClusterKMeans benefit from a spatial index? here is how I am using it (24313 is projection in meters): ST_ClusterKMeans( ST_Transform(d.bf_polygon, 24313), ...
analyst92's user avatar
  • 857
7 votes
0 answers
172 views

How to change the Point Cluster circle symbol to a convex hull

I am using the expression presented by the user JGH to solve the question 'Point Clustering in QGIS, but values show a percentage and not count of points' This shows my example: As you can see I use ...
Ingrid Ingravida's user avatar
3 votes
0 answers
65 views

Population clustering from Raster using ArcMap

I have a raster image with different pixel values, each one representing the number of people living in the pixel. I want to cluster the pixels based on the sum of the pixel values equaling 1000 in ...
Sahan Sankalpa's user avatar
0 votes
1 answer
204 views

MarkerCluster element popup does not appear when clicking a spiderfy element, instead unspiderfy is triggered in Leaflet

I have created a custom popup that appears whenever an element on my map is clicked. However, when spiderfy happens (when a marker cluster is clicked and the map cannot zoom to a level that would ...
ysi_d's user avatar
  • 23
1 vote
0 answers
378 views

MarkerCluster does not zoom when cluster clicked if it cannot reach a zoom level that will separate elements. How can I check for this? [closed]

I have a map with a maximum zoom level of 18. It is possible to have data points that are so close together that they are still clustered at zoom 18, and it is also possible to have multiple data ...
ysi_d's user avatar
  • 23
1 vote
1 answer
87 views

QGIS 3. Point Cluster rendering but with categorization?

Is there a way to obtain the same spatial rendering as what QGIS 3 allows with Point Cluster symbology (spatially close points clustered in a unique symbol) but using an attribute based categorization?...
Henème's user avatar
  • 33
1 vote
1 answer
19 views

Kmeans - putting k as the number of rows in the partition window / 10

I want that instead of using the same value of k for all my partitions as shown below, I should select k as the number of rows in the partition window / 10, is this even possible? My current code is ...
analyst92's user avatar
  • 857
7 votes
1 answer
161 views

Point Clustering in QGIS, but values show a percentage and not count of points

I am utilising mobility location data of common evening points from a Geofenced area to determine the trade area of a specific shopping centre. To visualise this for the clients, I need to group ...
Johanza24's user avatar
1 vote
1 answer
78 views

Cluster assignment in ST_ClusterKMeans

If I have 100 rows of polygons, and I choose number of clusters to be 10, is it always the case that each of the 100 polygons would be assigned to a cluster? So there will never be a "leftover&...
analyst92's user avatar
  • 857
0 votes
0 answers
40 views

Convex Hull on clusters generated by Kmeans

I am trying to use Convex Hull on the result of K-means. Here is my code: with data as( select at2."name" as area_type, a.name,bf.* from building_footprints bf left join area a on bf."...
analyst92's user avatar
  • 857
0 votes
0 answers
38 views

ST_ClusterKMeans max radius parameter not working as expected

I am trying to make clusters of maximum 20 buildings. Here is my code so far: with data as( select at2."name" as area_type, a.name,bf.* from building_footprints bf left join area a on bf.&...
analyst92's user avatar
  • 857
0 votes
2 answers
65 views

ST_ClusterWithin logic and usage [closed]

My data."geoJson" column has EPSG 4326 and SRID undefined for some reason. I am using dbscan as follows (with correct results): ST_ClusterDBSCAN(st_transform(data."geoJson",24313),...
analyst92's user avatar
  • 857
0 votes
0 answers
35 views

Setting a maximum limit for items in a cluster

I am combining dbscan and kmeans to get clusters with 1 to 10 items. Here is my code so far: with data as( select at2."name" as area_type, a.name,bf.* from building_footprints bf left join ...
analyst92's user avatar
  • 857
0 votes
1 answer
219 views

Variable number of clusters in K means

Here is my (relevant part of) the code: rejected_dbscan as ( select * from dbscan where cluster_id not in (select cluster_id from filter) ) , kmeans as( SELECT "ID", ...
analyst92's user avatar
  • 857
0 votes
0 answers
19 views

Max of cluster_id in DBSCAN equals number of unique clusters or not

select count(distinct cluster_id) from rejected_dbscan union select max(cluster_id) from rejected_dbscan results in 8708 41128 Shouldn't the two values be equal? Does the max of cluster_id in ...
analyst92's user avatar
  • 857
0 votes
1 answer
85 views

Leaflet.markercluster with GeoJSON via AJAX [closed]

I am pretty new to this. Have found a similar question here but I have been unable to implement it in my own case. The markers show up just fine but no clustering happens. function onEachFeature(...
SoranDK's user avatar
  • 11
0 votes
0 answers
22 views

Generating new polygons based on sum of values

I am working with QGIS, and I have created the styled density map with the hexagons to calculate pop figures within these. The pop field is displayed inside each polygon. I now want to create new ...
A_Y's user avatar
  • 91
0 votes
1 answer
107 views

Property e.propgatedFrom.feature not available in marker cluster click event in Leaflet

In a Leaflet map, when a point feature is clicked I want to capture its attributes and pass them onto some variables. The point feature is part of a cluster. The leaflet marker cluster is sourced as ...
user3072602's user avatar
0 votes
0 answers
103 views

Way for popups to be shown when using the clustering feature of QGIS2Web (Leaflet)

I have been making use of the QGIS2Web Plugin (current version 3.16.0) to create interactive maps (Leaflet) with great success thus far, however I have now discovered an issue when I use the "...
Caties96's user avatar
0 votes
1 answer
234 views

Clustering points with maximum number of points using QGIS

I have a dataset of 488 GPS points which I would like to break up into small clusters. The maximum number of points per cluster should be 3. I have tried the K-means clustering tool in Vector Analysis,...
bellbyrne's user avatar
0 votes
1 answer
2k views

Setting marker cluster icon color dynamically in Leaflet?

In a Leaflet map, when a school point is clicked it passes an id of that school and adds a student point layer specific to that school. The point layer is rendered on the map as marker cluster. So, ...
user3072602's user avatar
3 votes
0 answers
131 views

Accuracy assessment of unsupervised clustering - GEE

I have clustered my map on the basis of NDVI values using an unsupervised approach. I don't have the labels. However, I do have the cluster IDs that were automatically assigned. How do I assess the ...
th145's user avatar
  • 25
0 votes
0 answers
74 views

Mapping groups' data on the map using Map.addLayer - GEE

I wanted to extract the areas of specific clusters. I asked this question. I wanted to extract the areas of object-based clusters but the answer I got, resolved my issue. I need to visualize the ...
th145's user avatar
  • 25
2 votes
0 answers
143 views

Measuring and comparing 'closeness' of two different clusters in QGIS

i'm doing a paper for university and i'm having problems with statistical analysis in QGIS (v.3.28). i have two sets of waypoints (nests) from two different years plotted on a beach in QGIS. visually ...
aaaastayinalive's user avatar
2 votes
0 answers
179 views

Mininum cluster size in QGIS ST-DBSCAN sometimes not applied correctly

I have 7 point vector layers which I am clustering as a batch in QGIS using the standard ST-DBSCAN tool. On one instance, I formed two groups based on different minimum cluster sizes: 7 or 10. The ...
Barbara Perez de Araújo's user avatar

1
2 3 4 5
13