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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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Clustering based on asymmetrical adjoint matrix [on hold]

I am trying to find a way of finding clusters in directed transport network. Most of the methods that I have looked at get a result by either looking at the X/Y coordinate of a vertex in the network ...
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1answer
28 views

ST_ClusterDBSCAN in PostGIS gives me 0 for the cluster ID

I am trying to cluster latitudes and longitudes from a dataset containing locations in Germany (n=52612, about 9000 without duplicates). I am running the DBSCAN algorithm, but for none of the ...
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1answer
59 views

qgis2web map: performance issues with (clustered) point features

How do I get a point features layer containing roughly 2800 labeled features to perform smoothly when exported (and converted to GeoJSON) with qgis2web? Specifics: I use qgis2web 3.4.0 and QGIS 3.2.3 ...
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1answer
53 views

Clustering point data in QGIS?

Working in QGIS 3.4.1 Madeira I have a layer with many data points, for visual purposes I wish to remove some of the overlaying points. Is there a simple way to perform some sort of clustering/...
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1answer
34 views

Point Cluster in QGIS and Legend

I am using the point cluster symbology in QGIS and have defined the size of each point based on the cluster size using @cluster_size in the size assistant. It looks great on my map, but I cannot ...
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42 views

Cluster LineStrings using HDBSCAN?

I am trying to cluster a set of LineStrings (made out of lat/lon Points) with the help of HDBSCAN (using the "haversine" metric). The objective is to define the most "usual" path. I have only managed ...
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32 views

Algorithm to cluster coordinates within a maximum radius [closed]

I am looking for an algorithm that will allow me to find the centers of clusters of an arbitrary radius, such that all coordinates are covered. Currently, I am doing a very basic routine where I ...
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18 views

Clustering geo points and export borders in KML

How can I get geolocation points (lat, long), use any classifier (example: kmeans) and generate decision boundaries and export a KML of the formed clusters? I have a table where each row is an order ...
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1answer
128 views

Server side clustering with geohash

I need help with clustering algorithm. I have a mysql database with lat, lng, geohash(12 chars). I am usign this query to select all records for zoom level 2 (2 chars) SELECT COUNT( id ) , LEFT( `...
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1answer
81 views

Creating Groups of points based on proximity in QGIS?

I have a dataset with around 900 points and I want to cluster them into groups of 44 based on proximity. Is this possible in QGIS? I have tried to use the convex hull tool with no success.
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1answer
38 views

Adding values from a table to an image band - Google Earth Engine

I'm trying to add values from a table to a cluster image. The cluster image has 50 cluster classes, and my table has 50 values for each cluster class. How do I add the values from that table to the ...
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67 views

How to reclassify cluster image based on values from zonal statistics - Google Earth Engine

I have classified an image with 50 clusters (k-means). The next step is to reclassify the image into several meaningful classes (e.g. vegetation, urban, water etc...). I want to take an automated ...
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Using output of unsupervised cluster analysis to train supervised classification for vegetation mapping?

I'm using Google Earth Engine to classify mangrove forests from Landsat imagery to calculate extent. Let's say I perform an unsupervised K-means cluster analysis on a Landsat scene to identify general ...
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1answer
76 views

data-defined attributes in QGIS' point cluster symbols

I'm wondering how data-defined attributes work for the cluster symbol when using the point cluster layer styling in QGIS 3.*. How can you use the values of the points within the cluster for data-...
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38 views

Data-driven cluster colour with mapboxgl

I am trying to draw circle which colour depends on a "group" attribute in my geojson. I followed a simple example with these colours: map.addSource("data", { type: "geojson", data: url, ...
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22 views

What is the best way to Clusterise Salinas dataset with highest accuracy?

I am trying to clusterize every band of a Salinas dataset (as a fair duplicate of ground truth) using kmeans and cmeans, but they are both disappointing! The spectral signatures of every available ...
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2answers
99 views

Create buffers from points by attribute

Suppose I have a points shapefile with a 'group' attribute, each value of which identifies a number of points (e.g. group=1 identifies points 1,3,6 and group=2 identifies points 2,4,5). How can I ...
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66 views

Grouped “labels” for QGIS 3.0 Point Cluster styling?

I'm trying to make a cluster visualization of a vector point layer about trees with a few requirements: The clusters need to change depending on zoom level (solved) The clusters need to indicate how ...
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41 views

cluster polygons with scipy linkage using the bounding box

I'm trying to cluster some polygons and so far I'm using linkage following this tutorial with the polygon's centroids and cutting the cluster at a specific max_distance. The results are not as ...
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1answer
116 views

Finding geometry of cluster from points collection using PostGIS?

I have a regular grid, each point in the grid belongs to some cluster, and I need to find geometry of this clusters. My tables look like so (only necessary fields): grid_nodes( *id uuid, ...
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1answer
57 views

Point Similarity Clustering

I am new to geographical statistics so please pardon this question if it is a duplicate. I would like to test if points that are similar are more or less likely to be near each other. I am latitude ...
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0answers
28 views

K means clustering where centroid is a node

How would you approach a k mean clustering where the calculated centroids have to be on the same position as one of the nodes? as you can see we have 2 centroids which are arguably the center of each ...
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89 views

Is Spatial clustering with PostGIS possible to generate N number of groups that have 10 elements?

I need to create a query using some sort of spatial clustering algorithm within PostGIS database. Currently, I am using pgAdmin version 4. More specifically, I need to create N number of groups that ...
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1answer
58 views

Filter clusters in PostGIS by size

I am clustering points in a table based on their Mercator distance (~10km, it doesn't have to be that precise, so I'm fine with projection distortion). What I want to achieve is to only query the ...
18
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1answer
476 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 ...
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1answer
191 views

Label display based on cluster size

In QGIS 3.0, I am using the new clustering style. I want to display labels based on cluster size. What I tried in expression field: case when @cluster_size>5 then "label_name" end
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39 views

Split shapefile to approximate area

I have a shapefile with multiple polygons of different sizes and want to split this shapefile to new ones trying to achieve a determined area, but without splitting any polygon. For example: I want ...
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1answer
375 views

Dynamic point clusters in QGIS

I have a point layer with singular points set with high accuracy to the position of certain sites, each point representing one site. There are 8 different types of site. When representing these points ...
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0answers
23 views

Importing xy layer with projection / Ripley's K analysis in ArcMap

I am new to ArcMap. I have a data set with a couple of thousand points. I ID'd objects in photos; each photo had a lat/lon recorded; each object was given a lat/lon based on its pixel location in the ...
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0answers
37 views

Spatial Clustering for a cluster value sum [duplicate]

I am looking to spatially cluster a series of polygons of countries The resultant groups are spatial constrained (next to one another) and need to a have a group sum greater than a certain value. ...
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0answers
74 views

Cluster Points on spatial network in R/QGIS

I am searching for a method for clustering spatial points along spatial lines. The points are connected to the lines. I tried nearest neighbour clustering and gProject/gInterpolate from the rgeos ...
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1answer
40 views

How to re-assign attributes based on spatial relationship

I want to re-assign the attributes of a table of regular polygons based on their spatial relantionship so that the polygons are clustered like this: This essentially means to swap the attributes from ...
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43 views

Creating polygon boundaries to group points based on common attributes using ArcGIS Desktop? [duplicate]

Does anyone know of a tool, algorithm or code that I can use to create boundaries to group points? Some groups are in defined, obvious clusters and some are mixed with lots of different coloured ...
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1answer
48 views

Dissimilarity and distance based clustering around outliers using R? [closed]

I have point data for healthcare facilities for a country - I want to first identify outlier facilities (that serve most no of patients) and then cluster nearby facilities that serve lower than ...
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1answer
332 views

Filter Clustering Mapbox GL JS

According to @Mourner in this gihub issue regarding filtering cluster in Mapbox here. "you'll have to filter manually and run setData to reset the whole dataset..." I have also found an example ...
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0answers
111 views

QGIS - Distance between cluster analysis not working with K means and taking to long with hierarchical method. Any advice?

QGIS- Trying to carry out a cluster analysis regarding the density of villages in Kazakhstan. I am placing latitude and longitude as my fields and not sure if this is correct (see image). ...
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0answers
36 views

Analyzing point feature distribution

This is a followup to Evenly assigning attributes to layer of points using ArcGIS Desktop? that was answered about evenly assigning an attribute ("A" or "B") to a collection of fixed points. If I ...
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1answer
359 views

How to cluster external geojson (using leaflet.ajax.js)?

Understand the method of marker clustering but unable to find the right solution for external geojson. I have tried various cluster plugins but nothing seems to work. See example map here. var ...
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0answers
168 views

Smoothing borders of polygons taking a layer of points into account

I'm trying to smooth borders that separate clusters of points. GRASS instrument v.generalize.smooth works pretty well, except that in some cases the points end up on the wrong side of the smoothed ...
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0answers
352 views

Is it possible to color the cluster base on marker color?

So far, I've been able to generate the marker color base on query from my MySQL DB. What I would like to attempt now is to cluster those markers with the dominant marker color. For example, if I ...
2
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1answer
511 views

Can a featureGroup be added to another featureGroup in leaflet?

I have some points that I want to be clustered in a L.MarkerClusterGroup, which works well: var cluster = new L.MarkerClusterGroup(options); features.foreach(function(feature) { var layer = L....
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0answers
259 views

Clustering of polygons on map using Leaflet? [closed]

There is a plugin for Leaflet to cluster the markers.The result looks like so. Result: If I like something to do to show clusters of circles and polygons? For example, when you hover over a cluster ...
2
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1answer
388 views

Using ST_ClusterDBSCAN on results of ST_ClusterKMeans for nested clustering with PostGIS?

I would like to pipe the results of ST_ClusterKMeans() into a ST_ClusterDBSCAN() query. The ST_ClusterKMeans gives me a fairly good results as shown in this screenshot. I classified the union of the ...
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1answer
81 views

Cluster points of a layer into a grid [duplicate]

I have a layer with many points on a country, for example, Peru, and I have done a grid grouping all the country. Each hole of the grid has an ID so it's easy to differentiate them. My idea is to set ...
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1answer
167 views

Calculating Similarity between Two Clusters in QGIS?

I am new to GIS and I have a question to ask about how to calculate the similarity between two rasters in QGIS. I have generated two interpolations of plant water status in the exact same field for ...
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0answers
58 views

Choosing Shortest Path Algorithm for multi point routing? [duplicate]

I have a problem for which i am not sure which algorithm would be suitable. I have a bunch of customer outlets, every day my customer van need to deliver goods before certain time. Using GIS routing ...
2
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1answer
282 views

Point clustering based on a certain value

I'm trying to cluster points based on the sum of a attributes of its nearest neighbors. So here are the points in the data set as they are: The objective is that each point has an "evalfield" ...
3
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1answer
117 views

How to incrementally add points to a polygon and eventually increasing the size of the polygon in postgis?

I want to implement a clustering algorithm in postgis in which new points are incrementally added to an existent polygon and the polygon subsequently increases it's size to a the minimum possible ...
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0answers
202 views

Display feature reduction Clustering points count ArcGIS js feature layer?

I am able to cluster the points in the map using the following code: var serviceUrl = "https://services.arcgis.com/V6ZHFr6zdgNZuVG0/arcgis/rest/services/Places_of_Worship_India/FeatureServer/0"; ...
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0answers
118 views

Find number of weighted point clusters & centre of clusters

I have a points layer with a frequency field indicating a population at that point. There is also a field indicating the broader area by which I need to analysis broken down into. I am expecting the ...