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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16 views

Group nearby pixels in Google Earth Engine [closed]

I have a population raster layer in GEE and I would like to create pixel clusters based on proximity. I have tried some unsupervised clustering algorithms but these seem to cluster based on the pixel ...
5
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1answer
69 views

Variogram for clustered data point

I would like to study the spatial dependency in my dataset of a variable (crop yield) spread across a country with 250 sites. A first guess was to use a variogram on the data. However, I am not sure ...
98
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7answers
44k 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 ...
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0answers
39 views

Obtaining “nClusters” value in Google Earth Engine

After training the kmeans model, how can i obtain the number of classes of the model? i've tried with get(), getInfo() and doesnt work. https://code.earthengine.google.com/...
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0answers
15 views

Get “nClusters” value from GEE [duplicate]

After training the kmeans model, how can i obtain the number of classes of the model? i've tried with get(), getInfo() and doesnt work. https://code.earthengine.google.com/...
10
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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 ...
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2answers
20 views

Clustering Raster Monthly Precipitation Pattern

I am looking for a way to automatically cluster the monthly rainfall data that I have like the Koppen Classification Map. I have 12 raster files of precipitation (months of Jan-Dec) of a country and I ...
1
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0answers
161 views

Determining spatial cluster of park types in ArcGIS Desktop [closed]

Question 1: I am trying to determine which (if any) of my different park types are spatially clustered across my study area (city boundary). There are 162 total parks, 9 nominal categories (which ...
2
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0answers
18 views

How to cluster points based on network traveling time to a common location?

I have a set of points that I need to divide into N different clusters. I know how to do this with the arithmetic distance, but in this example I need to cluster them based on the network traveling ...
4
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1answer
883 views

How to Construct Spatio Temporal Clusters of Time Series Data in R

I have count data of one disease for various districts of a state of India on monthly basis. Is it possible to draw spatio temporal clusters in R? I have checked some R- packages for example ...
3
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2answers
776 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( `...
1
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1answer
59 views

Speed up GeoJSON clustering and rendering?

I am rendering 10,000 points with Leaflet's markercluster library. I fetch these 10k points from our server. This takes about 700ms. It takes Leaflet about 3 seconds to cluster these points and ...
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3answers
10k views

Leaflet markerClusterGroup 'undefined is not a function'

I have to create a map with more than 5000 points from a geojson. So I would like to use markercluster plugin with Leaflet. I wrote the following code with help from the documentation and from other ...
2
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0answers
33 views

PostGIS - create polygons from clusters of a fix number of points

I have a set of about 120,000 points, not regularly spread. I would like to cluster them in order to create groups of about 3,000 points, regardless the distance. The final goal is to create ...
1
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1answer
30 views

Processing dbscan by group

I am new to Postgis and I need to do DBSCAN by commune. I have the base dir_v2: id_dir geom commune I need to process clustering at least 1000 points in a radius of 1000 meters per commune but it ...
3
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1answer
44 views

Clustering of points based on 1 or 2 attributes

In QGIS: I have data of sightings of a particular animal that has been mapped as points. Some of these may be repeated sightings. I've classed the sightings according to 'SightCode' which represents ...
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1answer
56 views

Style OpenLayers.Feature.Vector in OpenLayers.Strategy.Cluster()

I'm using the clastering feature in my project. I collect list of points like so: cluster_features.push(new OpenLayers.Feature.Vector( new OpenLayers.Geometry.Point(lon,lat), {heading:deg} )...
1
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1answer
180 views

K-means clustering in QGIS with statistically significant difference

Anyone knows that how to do K-means clustering with significant difference? What I means is as the image shows, the area is divided into two zones using k-means clustering, and the significant ...
3
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1answer
691 views

Using SAGA Cluster Analysis for grids projection

I am having an issue with the SAGA cluster analysis for grids tool within QGIS 2.4. I am actually taking this as an online class through Del Mar and we are going over supervised and unsupervised ...
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0answers
28 views

Defining Parameters using Spatially Constrained Multivariate Clustering of ArcGIS Pro

I have a point shapefile with 51673 features. I am trying to cluster them using the Spatially Constrained Multivariate Clustering tool in ArcGIS Pro. After reading through the documentation, I'm ...
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0answers
27 views

Providing a qualitative description of the results from DBSCAN clustering

I have run a DBSCAN clustering algorithm in QGIS 3 on bus stops in my specific study area where my minimum cluster size is 50 and maximum distance is circa 9km. After this I created a concave hull of ...
1
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1answer
203 views

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 ...
2
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1answer
155 views

Find EPS for DBSCAN

I have location posts from Instagram Data and want to cluster them by density - using DBSCAN. I played around quite a lot with different minPts and eps but never receive clusters (always one big ...
4
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2answers
121 views

Display millions of locations very, very fast

We're building a mapping application for voter data using PostGIS and Leaflet. It has a web interface. Our voter file will have several million entries. In our app you can select a subset of the voter ...
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2answers
145 views

Identify lat long points falling out of cluster

Problem Statement I have a set of lat-long locations, say 30 in number. Ideally they should be just a few meters from each other on ground. But sometimes there's that odd junk data point that's 20kms ...
6
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2answers
1k views

Using GROUP BY linear spatial clusters with PostGIS

I have a series of points in a horizontal line, arranged into discrete spatial clusters by the underlying data pattern. Here's an example of what they look like: How can I use PostGIS to group them ...
5
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2answers
790 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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0answers
53 views

Browse features in cluster won't work in ArcGIS Web App

After creating and configuring a web app i realized that the "browse features function" included in the cluster pop-up does not work properly when clicking a point layer's cluster icon. After showing ...
3
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3answers
2k views

Is it possible to distinguish between points with the same coordinates?

I have several points with the same coordinates in one layer and of course they are located on top of each other. Is there a way to separate these points automatically (not manually)? I don't want to ...
8
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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(...
2
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0answers
24 views

Importing hdbscan in QGIS plugin?

I am building a QGIS plugin and would like to add hdbscan in methods. But when I import with OSGEO4W shell it failed at this line: File "C:\OSGeo4W\apps\Python37\lib\site-packages\hdbscan-0.8.22-...
2
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0answers
41 views

Displaying sum of field in cluster symbology using QGIS?

Using QGIS, I have a point layer of wind turbines. One of the fields is MW (megawatts produced by the turbine). I want to display the turbines by clustering. But I to show the sum of MW in the ...
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1answer
128 views

Clustering spatial lines in R by direction

There are tens of ways to cluster spatial points in R but I couldn't find any for spatial lines. What I would like to get is the average trajectory directions that each of these cyclones (spatial ...
4
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1answer
68 views

Clustering only if name attribute is same using QGIS?

I have a point layer on a world map with several attributes. Each point marks the position of a berth at a terminal in a port in a certain country. When I zoom out, it's getting too crowed so I ...
0
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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
111 views

Change maxZoom level on Leaflet Marker Cluster Group?

Our leaflet web app allows users to switch between tile layers. The tile layers sometimes have different max zoom implemented by the tile provider or local config. We have another layer with ...
-1
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1answer
102 views

Running cluster and outlier analysis gives ERROR 999998?

I am attempting to run Cluster and Outlier Analysis on a Shapefile Feature Class. The geometry type is a line feature class. I am receiving the following error when attempting to use this tool: ...
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2answers
100 views

Problems with ST_ClusterDBSCAN cluster sizes

I want to cluster all villages (and towns, ...) around the world. So instead of having millions of them, I'd like to reduce them by combining villages that are close enough (like 10km or so) to each ...
4
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1answer
769 views

Adding python module to QGIS python interpreter on mac?

I'm on OS X El Capitan running QGIS version 2.18.2 which I installed via the Kyngchaos installers. I'm trying to install a plugin, which requires, among other things, that Pysal needs to be installed....
6
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1answer
435 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.
-2
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1answer
55 views

Cluster Analysis on spatial data on R? [closed]

I sampled a population of an insect in an area and got GPS points. Now I want to investigate if there are subpopulations within the pop using distance from points. I have a dataset with coordinates ...
3
votes
2answers
89 views

Applying ST_ClusterDBSCAN repeatedly until cluster sizes small enough

I am looking for a way to spatially clusters thousands of datapoints (potentially millions) based on distance, such that each cluster contains less than 5000 points. This is a similar question to ...
0
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0answers
19 views

Automating Cluster Assignment of Grid Squares?

I'm using MapInfo. I have a grid layer which has results assigned to each grid square. I'm wanting to automatically assign cluster references using a minesweeper style approach, i.e. where grid ...
1
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1answer
78 views

L.esri.Cluster.featureLayer does not call style function

Using the L.esri.Cluster.featureLayer plugin for Leaflet to cluster features from Esri does not call the style method despite the documentation stating that this is the way to style vector layers. ...
2
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0answers
25 views

Clustering raster based on area of specific number of pixels

I'm currently looking at overflows of rainwater in a region and I want to find all the puddles, which have a restricted size and a minimum number of pixels in them and create a vector layer where each ...
1
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0answers
64 views

QGIS > Concave Hull plugin > Shared Nearest Neighbor Clustering

I have been using the Concave Hull plugin in QGIS & the Shared Nearest Neighbor Clustering feature. I am having issues with this plugin, each time I choose the option of "Number of Neighbours" it ...
1
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0answers
533 views

Creating clusters of nearby points using QGIS? [closed]

I m trying to create clusters of nearby points (which would be the adresses of my customers around a store). Buffer is not an option cauz i need the zone to be limited by customers, so a polygone ...
1
vote
1answer
44 views

Sample method returns empty featureCollection (GEE)

I have some troubles with the sample method from Google Earth Engine. On some images, it returns an empty feature collection (0 element). Why this is happening and how do I deal with that ? It's ...
-1
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1answer
177 views

Clustering plots points into groups based on their elevation using QGIS?

I have a plots shapefile for a region (polygon)converted to centroid points. I have added the geometry column to it and also added elevation attribute to every point by sampling the plots vector file ...
6
votes
2answers
781 views

Increasing marker size based on number of points at same location in QGIS

I have a dataset that contains many points (representing specimens) with GPS locations taken at the same point. When I map these points as a vector layer, only the uppermost point shows - so, at one ...