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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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137 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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217 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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1answer
679 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
410 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
180 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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177 views

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
234 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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2answers
438 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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0answers
246 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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1answer
268 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
78 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
35 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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165 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
103 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 ...
19
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1answer
928 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 ...
2
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1answer
604 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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53 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
793 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
154 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
50 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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0answers
88 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
78 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
782 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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196 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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1answer
646 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
192 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
529 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
960 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
493 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 ...
3
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1answer
906 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 ...
1
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1answer
120 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
277 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 ...
2
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1answer
550 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
189 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
328 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"; ...
3
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0answers
172 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 ...
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2answers
708 views

Getting number of clusters and its markers with Leaflet?

I would like to know the number of clusters and its markers as soon as I open the map without zoom-in. I'm using: Leaflet 1.2.0 Leaflet.MarkerCluster 1.2.0 Firefox 57.0.1 OS/Platform On the image ...
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2answers
1k views

Unsupervised classification using ISODATA clustering in R

Is there a way (e.g. package) to perform an unsupervised classification using the ISODATA clustering algorithm in R?
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0answers
208 views

Enforcing maximum distance with ST_ClusterWithin?

I have a set of location points and I want to find clusters within the set. This is fine. However, I don't want to get two points in the same cluster that are farther apart than the maximum distance, ...
2
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1answer
738 views

Cluster GeoJSON (linestrings and markers) into circles using Leaflet

I have different hiking routes (in geoJSON format) displayed on a map. They contain linestrings, multilinestrings and markers. Currently, it looks like this: http://www.hikethisway.today/Sweden.html. ...
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2answers
596 views

Performing spatial clustering of polygons based on attribute

I want to perform spatial clustering on the polygon which contains a number of total points inside it. I would like to ask if there is any ways that the polygons can be clustered based on the total ...
1
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1answer
2k views

Leaflet mouseover popup makes whole map move

I was following a couple of examples to get my leaflet map to show the popup for the marker when I hover over it. This example to show popup on hover. I also used example to do leaflet marker ...
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0answers
469 views

Clustering points into *n* number of groups of equal counts with ArcGIS

I have to divide points into groups. These groups will be used by agents to talk to property owners. The goal is to make the agent's job easy by grouping parcels that are near each other together, as ...
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2answers
101 views

How to cluster/group points based on their frequency and event time without overlapping them?

I am trying to group around 100 points based on their frequency and occurred month (similar to https://i.stack.imgur.com/i7Mzi.png) but I haven't found a solution yet. Tried many tools in QGIS but ...
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2answers
138 views

Reading attribute popup information from cluster presented points in the map generated via qgis2web?

I have a problem with a web map generated via qgis2web plugin using clusters. I have a batch point data and many of these are on the same location. Because of that I have used cluster for representing ...
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1answer
354 views

Why is there a need to train the clusterer in Google Earth Engine

I'm wondering why before clustering the global Landsat-7 image in this tutorial, the authors first trained the clusterer on a subset region around Egypt? Since the Kmean algorithm is supposed to be ...
5
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1answer
324 views

Filtering out spatial-outliers from cluster of points using PyQGIS?

I have a cluster of points as seen below from a shapefile layer. I need an automated procedure (in PyQGIS or any) of filtering out those points that are outside or further-away from the center of the ...
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1answer
242 views

How to draw boundaries to separate clusters?

I have used the R Project for Statistical Computing to make a map of clusters based on latitude and longitude by using the k-mean clustering. Is there any software I can use to import the clusters ...
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0answers
3k views

Clustering latitude longitude data based on distance

I have a large dataset of latitude and longitude. I want to cluster the data into groups based on distance such that the distance between two points in a cluster is not greater than a minimum ...
3
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1answer
3k views

Finding nearest neighbors of each coordinate

I've got a list of coordinates (WGS1984 Decimal Degree) and have started work on a program that performs a DBSCAN on them to find clusters amongst them. To perform the DBSCAN's range query to ...