Questions tagged [clustering]
Partitioning data points into subsets of objects according to their mutual "similarity," without using preexisting knowledge such as class labels.
594
questions
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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 ...
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3
votes
0
answers
52
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 ...
0
votes
1
answer
38
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 ...
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1
vote
0
answers
48
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 ...
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1
vote
1
answer
38
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?...
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1
vote
1
answer
15
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 ...
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6
votes
1
answer
78
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 ...
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1
vote
1
answer
39
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&...
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0
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1
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38
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Cluster nearby points into a single polygon - SQL Server
I have a table with column shape of type geography where each row represents a point.
It's required to cluster nearby points (within a specified distance from each other) into clusters of type polygon ...
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0
votes
0
answers
19
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."...
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0
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0
answers
19
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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.&...
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0
votes
2
answers
40
views
ST_ClusterWithin logic and usage
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),...
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0
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0
answers
13
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 ...
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0
votes
1
answer
145
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",
...
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0
votes
0
answers
13
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 ...
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0
votes
1
answer
53
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(...
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0
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0
answers
16
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 ...
- 81
0
votes
0
answers
14
views
Add number of symbols defined in attribute table or how to set up cluster points with defined number of records in attribute table
I use QGIS 3.22.2 and I have points datasets of records from ecology surveys with few different species and with separate column with number of records in given location (point) - most of points have ...
0
votes
1
answer
49
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 ...
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0
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0
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43
views
Euclidean distance point Cloud clustering in R lidR
I'm looking for a way to implement the python function filter.clusters from the pdal package in R using the lidR package.
The function clusters pointclouds using the Euclidean distance, a tolerance ...
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0
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0
answers
48
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 "...
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0
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0
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52
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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,...
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0
votes
1
answer
464
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, ...
- 79
3
votes
0
answers
100
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 ...
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0
votes
0
answers
45
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 ...
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0
votes
0
answers
38
views
GeoServer clustering JMS extension problems
I am new to GeoServer Active Clustering. If having two GeoServer instances (2.22.0) running locally in Jetty, i.e.:
localhost:8080/geoserver
localhost:8090/geoserver
When installing the JMS extension ...
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2
votes
0
answers
50
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 ...
2
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0
answers
54
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 ...
2
votes
1
answer
151
views
Extracting area of the clusters of specific coordinates
I am working in GEE and I am trying to extract areas of clusters for some specific coordinates.
I have a clustered map of the area of all the clusters (using object-based clustering) and a list of ...
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2
votes
1
answer
44
views
Calculating time difference between rows of the same field separated by cluster ID in QGIS
I have just formed point clusters using ST-DBSCAN, which gave me a single output with all points categorised by the new column "CLUSTER_ID".
My next step is to acquire the centroids of each ...
0
votes
0
answers
57
views
Google Earth Engine: K-mean clustering of population data
I would like to cluster population data using k-means or weighted k-means and then display the clusters as various colours to help differentiate them. I can easily do this on python with a table as ...
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1
vote
0
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120
views
QGIS cluster points based on similar sum // maximum treshold of an attribute of each cluster
I need to cluster point layer features based on an attribute so each cluster has a similar total sum of this attribute values:
E.g. I have generated 1000 random points with values between 1-100. Task:...
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0
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60
views
Mean values of all the clusters - GEE
I have clustered an image collection using the following pipeline in GEE:
Applied clustering algorithm to sentinel imagery.
Mapped LST.
Calculated mean LST value for each cluster using the ...
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0
votes
1
answer
62
views
Getting cluster centers of entire "result" image (final gridded clustered image) [closed]
I have got the cluster centers by clustering the training data. Click How to get cluster centers and their values in Google Earth Engine? to review the relevant question. I still wonder whether the ...
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3
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0
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views
Coordinates: optimizing a table that contains lng/lat coordinates for clustering (in PostGIS)
I have table in PostGIS where I store coordinates in the 4326 lng/lat SRID, to make it easy to store GPS coordinates collected from mobile devices.
I'm using the coordinates to query the table based ...
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0
votes
1
answer
121
views
Getting cluster centers and their values in Google Earth Engine
I want to do clustering of an area in Google Earth Engine using temperature and precipitation (maybe more variables in the future). I have got the clustering result, but still want to know the ...
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0
votes
0
answers
46
views
Assigning Cluster IDs - connectedComponents. (Google Earth Engine)
I am trying to assign cluster IDs to clusters in Google Earth Engine. But I am facing an error.
Code:
var objectId = clusters.connectedComponents({connectedness: ee.Kernel.octagon({radius: 2}), ...
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0
votes
0
answers
18
views
How can I solve this error while trying to create cluster via pygeoda library
I'm trying to create clusters of a dataset with 'pygeoda' library based on a distance based wight and the max-p greddy algorithm, using the area of each polygon to indicate the maximum area that each ...
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0
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0
answers
14
views
Set VRP cluster using overrides parameter
I have a question about VRP.
How does parameter overrides work in the ArcGIS REST API?.
There are 2 ways to set overrides that I know of, namely "RSPPenaltyFactor" and "optimize for ...
1
vote
0
answers
101
views
Split a region into segments based on majority points
Having many points that belong to different classes (in the example below 9), I would like to split the region into multiple segments. In QGIS, the majority/minority tool does the job. In Python, ...
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3
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563
views
Clustering Algorithms for Geospatial Data
I am new to the world of Geospatial Analysis!
I am interested in learning about Clustering Algorithms that can be used for Geospatial Data.
For instance, suppose I have:
A shapefile for all ZIP Codes ...
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0
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0
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25
views
Create hierarchical school clusters
I have a CSV containing UK County data for schools.
For each school I have it's location, name, size (number of pupils), and phase (primary/secondary/tertiary).
I am trying to cluster the schools - ...
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1
vote
1
answer
269
views
Distinguish features inside a cluster with OpenLayers
Based on the OpenLayers Dynamic clusters example to tried to implement tooltips on feature mouseover. This works fine for unclusterd icons, but not for the ones which are too close to each other and ...
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0
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28
views
How could I replace fixed conditions to get clustering EPS for some calculation?
I use a function of DBSCAN for clustering, that takes the EPS value as a parameter (radius that defines which points will be grouped together).
To set the EPS I use the following switch case:
let ...
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2
votes
1
answer
49
views
Cluster_size function is not available
I'm using the version 3.28.2.
I combined the points in a cluster, and now I'd like to define the size of the cluster depending on the number of the points in cluster. However, the function ...
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7
votes
2
answers
317
views
Cluster polygons into equal parts in QGIS
I have a large area divided into three parts. Each of these parts is divided into smaller parts. Each part contains an amount of biomass that can be cut and sold. The total amount of biomass in the ...
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2
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139
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Fuzzy Clustering in Google Earth Engine (GEE) or the GEE Python API (geemap)
I'm using the GEE Clusterer algorithm (Weka K Means) to assign 30-m pixels over a large area (several thousand acres) to a predetermined number of groups.
The Weka K Means method is a "hard" ...
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3
votes
1
answer
134
views
clustering similar linestring with direction in PostgreSQL(PostGIS)
Linestrings with directions are stored in the form of geometry in PostgreSQL, as shown in the figure below.
I would like to cluster similar(location, length, and direction) shapes through functions ...
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1
vote
1
answer
120
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SNIC (Simple Non-Iterative Clustering) : Does each group of pixels indicate a different clusters or can two clusters (of different colors) be the same
Referring and quoting the SNIC (Simple Non-Iterative Clustering) paper:
In each k-means iteration, SLIC evolves a centroid by
computing the average of all pixels that are closest to it in
terms of d ...
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2
votes
1
answer
170
views
Grouping/Clustering Pixels in Google Earth Engine
I am trying to cluster the pixels in one class based on the pixel value. But when I execute this code then class1 is correctly clustered but class2 merges the pixels of class1 as well. Similarly, ...
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