Questions tagged [spatial-cluster]
Use this tag when referring to spatial clustering in GIS.
76
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Build Balanced zones based on non-linear distances
I am trying to solve a problem of polygon division based on XY of a GPS. Being so, I am using the "Build balanced zones" tool of ArcGIS Pro 2.8.1.
However, I am facing a problem which is:
I ...
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1
answer
37
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Calculating inter-point distances worldwide - a dilemma
I am new to GIS, and am to cluster geospatial datapoints using DBScan() in the fpc package on R. However, my dataset is in ESPG 4326 (WGS 84). Since WGS 84 stores lat-long as degrees, and not metres.
...
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14
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Identifying clusters of development affecting forested area
I am looking to identify clusters of development polygons (areas that will undergo construction works that may be detrimental to biodiversity) that will affect forested areas. The development polygons ...
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31
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Nearest Neighbour Index (NNI): how to compare values & in depth explanation of how to calculate expected mean distance
I have two questions regarding the ‘Nearest Neighbour Index (NNI)’, sometimes also referred to as ‘Nearest Neighbour Analysis (NNA)’:
I have calculated the ‘Nearest Neighbour Index’ for 4 different ...
- 542
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62
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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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27
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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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92
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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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210
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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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1
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229
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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 ...
2
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1
answer
79
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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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4
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205
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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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32
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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 ...
- 919
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2
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229
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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 ...
- 157
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121
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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 ...
- 35
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117
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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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71
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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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126
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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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140
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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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38
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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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25
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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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89
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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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176
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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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108
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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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1
answer
281
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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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2
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answers
103
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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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1
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141
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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 ...
10
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1
answer
4k
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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 ...
2
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1
answer
378
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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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210
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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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120
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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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1
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102
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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 ...
- 3,276
3
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190
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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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121
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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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2
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593
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Looking for QGIS equivalent of ArcGIS Pro "Build Balanced Zones" tool
The "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 ...
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3
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2
answers
675
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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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1
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647
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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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2
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1
answer
118
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 ...
- 705
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2
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810
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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 ...
- 919
2
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1
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286
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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 ...
- 141
3
votes
1
answer
117
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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 ...
- 3,031
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248
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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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281
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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 ...
- 380
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114
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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 ...
- 61
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54
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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 ...
user138966
3
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1
answer
155
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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 ...
- 197
3
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107
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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 ...
- 365
2
votes
1
answer
525
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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 ...
- 400
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538
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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 ...
- 129
4
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1k
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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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1k
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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 ...
- 153