Questions tagged [spatial-cluster]

Use this tag when referring to spatial clustering in GIS.

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Spatio-temporally cluster points per individual group using R

I require an efficient approach in R to identify clusters of points using the following rule sets: 2 or more points within 2 hours of each other should be clustered. Clusters that are within 150m ...
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17 views

Comparing Heatmaps over time

We have a huge dataset of mobile users (tourists) and want to see how the density in a city has changed (from one spot to another) before during Covid. Of course we can create a heatmap for different ...
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Local Moran’s I vs Getis-Ord Gi* for Cluster/Hotspot Analysis

I was wondering if someone could perhaps help explain the difference between these two methods and when it might be more appropriate to use one vs the other for cluster/hotspot analysis? I understand ...
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15 views

What methods can identify the randomness or clustering of data at scattered locations?

For a group of scattered points at given latitudes and longitudes, each point has a property x. If nearby points have similar properties, they are deemed clustered. What technique should I use to know ...
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97 views

How to cluster 1000+ points into 50 clusters based on geospatial proximity in R?

Sample data: set.seed(123) lon <- runif(1200, 72.6, 73.2) lat <- runif(1200, 18.8, 19.6) df <- data.frame(lon, lat) Progress so far: geo.dist = function(df) { require(geosphere) d <- ...
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125 views

R: Clustering observations together based on distance and time

In R, I have a dataframe with roughly 3 million observations, with the columns being longitude, latitude and time respectively. My goal is to form clusters (using a custom distance function), and then ...
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1answer
57 views

Differences in first-order Polygon Contiguity in ArcGIS - Contiguity Edges Corners (CEC) vs. Contiguity Edges Only (CEO) [closed]

I am working on spatial autocorrelation, and using the spatial modeling relationship methods available in ArcMap. In ArcMap, there are the following methods for polygon contiguity: Contiguity Edges ...
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1answer
66 views

If a Moran's I value is close to 1, then why is it necessary to report the p-value?

For instance, if we get a Moran's I value of around 0.6, then we already know based on that Moran's I value that spatial autocorrelation is present. Why is it important to additionally report the p-...
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23 views

Group PostGIS table-rows where geometries are close

In OSM there are often e.g. lines (paths) with the same name but different OSM-IDs. Right next to each other, so basically the same thing, but just different objects with no real relation to each ...
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137 views

Clustering adjacent polygons with values over a given threshold with Python

I have a GeoPandas dataframe that looks like the following geometry raster_val 0 POLYGON ((1.85626 49.12003, 1.85626 49.11171, ... 28.530001 1 ...
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1answer
68 views

Creating homogeneous groups of areas from raster using QGIS

I'm trying to create homogeneous groups of areas from a raster which contain elevations data (in the red area). currently I am doing it manually creating new polygons for each groups. Is there a way ...
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58 views

Creating polygons based on attributes in point layer using ArcMap

I have a point layer of residential coordinates which includes an attribute field indicating the most visited hospital for the people living at the coordinate. From these data, I want to create a ...
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45 views

PostGIS: Creating Polygon from lots of other geometries and then returning list of ID's in the same query

I am fairly new to all of this but in simplistic terms I have the following problem: I need to create lines from points, and from said points group all of those within n distance of one another. From ...
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1answer
95 views

How to choose limited number of points to represent a point grid

I need to choose a few points to represent the grid below, e.g: 8 points in the grid below. This point need to be geographic distributed This points needs to be geographic distributed. Lets see a bad ...
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123 views

DBSCAN with huge number of points

We have a dataset of approximately 30 million new points per month (latitude, longitude, and a measurement associated with that point). So far, we have applied DBSCAN to generate a monthly map such ...
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1answer
34 views

Keeping only highest point in cluster of points using ArcMap

i have a cluster of points in particular areas around NZ. I am only wanting the point with the highest value in this cluster to remain. Also many of the points have the same value, i am just wanting 1 ...
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If there is no spatial autocorrelation, should the spatial cluster detection be performed?

I have a regional count data of disease incidence. First, I calculated empirical Bayes estimate of standardized morbidity rate. Then I performed global Moran's I to check for spatial autocorrelation ...
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1answer
74 views

ArcGIS JS 4.15 Cluster Popup navigation for Cluster

I would like to migrate from ArcGIS JS API 3.x to 4.16. One other feature I am using from 3.x version is clustering. In 3.x is it allow user to click on Cluster marker and navigate between all ...
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115 views

Distance computation for geospatial clustering of lat/lon points

I am working with a pretty large dataset (~500K data points) in Python (GeoPandas) and I would like to perform geospatial clustering on some subsets (~60K points) of the data. My question has to do ...
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79 views

Evaluating statistic significance in Neighbour Nearest Test using QGIS

I'm reviewing a scientific article to be publish. I tried to evidence that pathogens collected from different geographic areas clustered. I used Nearest Neighbour test to prove it. However, I've ...
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1answer
228 views

Statistic for measuring (local) autocorrelation of ordinal data

I have a spatial data set with a bunch of variables in nine-level ordinal scale. I want to calculate (local) spatial autocorrelation for each of these ordinal scale variables. I've been using ...
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67 views

How to cluster interconnected lines in Python without PostGIS?

I'm working with a subset of data from OpenStreetMap, where I have these island-like groups of line features. The groups are not connected to one another, but the lines are all interconnected within ...
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1answer
101 views

Clustering large number of locations

I am trying to cluster points inside the USA for which I have the latitude and the longitude. My condition is that, every point within a cluster should be less than 25 miles away from every other ...
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1answer
3k views

Clustering points in PostGIS

I am trying to cluster points in PostGIS. I have the points and the corresponding Latitudes and Longitudes which I have converted into point geometries. I want to cluster points in such a way that all ...
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1answer
276 views

PostGIS Recursively Finding Intersections of Polygons to Determine Clusters

My dataset currently contains about 15.000 buildings which partially touch each other. The objective is that those which do touch should belong to a cluster. This "basically" works but the main issue ...
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166 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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1answer
79 views

Cluster analysis based on both location and attribute (seconds)? [closed]

I'm looking to create clusters both on spatial density, as well as an attribute (time, in seconds). Essentially, I am trying to figure out what areas are choke points in terms of time spent at certain ...
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1answer
79 views

Create point clusters based on grid

I am trying to make a systematic cluster sampling pattern for data collection. The sampling consist of the points placed over the landscape in 6 km span (red). From this major point, I need to create ...
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1answer
164 views

Clustering geometry points, return a point's label if the point does not belong to a cluster?

I am clustering geometry points using the k-mean algorithm. The result is a list of clusters. Some clusters contain multiple points. Others only contain a single point. On the client side, we would ...
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1answer
109 views

Create fake clustered raster data in ArcGIS [closed]

I'd like to create several polygon grids with fake species occurrence (see example image) where each grid cell has a random value between 0 and 5 but high and low values cluster in certain areas as ...
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470 views

Is there an equivalent to "Build Balanced Zones" from ArcGIS Pro in QGIS?

"Build Balances Zones" was introduced in ArcGIS Pro 2.4 and allows a kind of spatial clustering with the help of genetic growth algorithm: The Build Balanced Zones tool uses a genetic algorithm to ...
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2answers
552 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 ...
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1answer
561 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 ...
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1answer
104 views

Applying QGIS point cluster exception

I have applied a point clustering effect on a layer in QGIS. What I'd like to be able to do is cluster on all features except the ones that I have a NULL value in an attribute. I can Categorize on ...
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2answers
661 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 ...
2
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1answer
250 views

Fixing colors of LISA Cluster maps from Pysal?

I am using the LISA Cluster package from Pysal to create a LISA (Local Indicator of Spatial Autocorrelation) map. As the example of the documentation shows, the color lightblue is used to identify ...
3
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1answer
113 views

Get the probable right location from multiple points

I have a location collection tool which send me location data of our survey. Surveyors send multiple data of a single item. Such as they send numarous data for a school like the following image. From ...
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1answer
211 views

Spatially constrained multivariate clustering in ArcPy gives AttributeError?

i want to use the Spatially constrained multivariate clustering tool for a point shapefile. I'm using PyScripter. The shapefile is named "LITO2016_area_modelli_20190312_v2" and the attribute fields i ...
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1answer
193 views

Creating clusters based on attribute and proximity [duplicate]

In my map as you see below, I have my population by district. I want to create 50 clusters with similiar sums of the population and by proximity. How I can achieve this? For each cluster, I want the ...
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1answer
106 views

Calculating Moran's I for buffers of forest cover?

I'm trying to figure out if buffers I have created in ArcMap (measuring percent forest cover in a 1 km distance from a land use map within the buffer) around points at which I will be collecting ...
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53 views

Point patterns clustering around reference points?

I have two point shapefiles. I want to analyse whether the points in the dataset A are clustering around their respective reference point in the dataset B. Each reference point in the dataset B has a ...
3
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1answer
128 views

How to UPDATE a column with cluster IDs in PostGIS?

I have a table with points in it, and I want to cluster them. I had created a separate table to hold the clusters, but I ended up copying all the data from the original table into the new cluster ...
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84 views

Clustering based on eqaul populations

I have a map of a city that is divided into 65 sectors (building lots in purple, sector boundaries in red): In my shapefile of building lots, I have an attribute that is the total population within ...
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1answer
343 views

Cluster geometries that touch each other

I'm trying to cluster the geometries in a sf object that touch each other. For the moment I'm using the same approach that it's explained in the answer here, but the problem is that the same idea ...
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1answer
385 views

Combining points close to one another

I need an approach to combine points close one to another into a common point. I can take an average of points' {lat, long} to create one point. How I can do this with ArcMap or Python? I have an ...
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0answers
1k views

PostGIS - Dynamic Server-Side Clustering based on Zoom level

I'm working on a Ruby on Rails application that is showing road signs on the map(leaflet). So, user can browse map and road signs, great. But, if there are a lot of signs and user wants to zoom out, ...
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1answer
1k 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
1k views

Clustering spatially connected polygons so all clusters have approximately the same size

I want to group together polygons from a shapefile a way that all the clusters formed contained approximately the same number of polygons. The problem is that the source polygons have vastly ...
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247 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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689 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 ...