Questions tagged [spatial-cluster]
Use this tag when referring to spatial clustering in GIS.
89
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Cluster points based on a maximum distance to each cluster's center
I have a layer of buildings (points). I would like cluster as many of them as I can around a common point in space in such a way that all the members of each cluster have a maximum distance of 100 m ...
0
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1
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139
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Modify the “kmeans” function to include the condition that all cluster centers have a value from a given raster
I would like, if possible, to add a condition to the “kmeans” function. The condition is that all centers of final clusters must have values from a given raster, and thus, should not contain any NAs.
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88
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Clustering points with maximum number of points using QGIS
I have a dataset of 488 GPS points which I would like to break up into small clusters. The maximum number of points per cluster should be 3.
I have tried the K-means clustering tool in Vector Analysis,...
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2
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73
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Measuring and comparing 'closeness' of two different clusters in QGIS
i'm doing a paper for university and i'm having problems with statistical analysis in QGIS (v.3.28). i have two sets of waypoints (nests) from two different years plotted on a beach in QGIS. visually ...
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126
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Point Stacker GetFeatureInfo
I've got a sld globally inspired by those posts (and a lot of others):
GeoServer – Creating Stacked Points
GeoServer Point Stacker: does identify work on non-clustered points?
Point Stacker in ...
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109
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How to mask a raster and apply an unsupervised classification? R
I am getting the error:
In matrix(values, nrow = ncell(x), ncol = nlayers(x)) :
data length [6691] is not a sub-multiple or multiple of the number of rows [25628]. In reaction to knr <- setValues(...
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2
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150
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Multiply two rasters in R, one raster has stack of 25 images, and another raster has one image
I want to multiply two rasters (one has 25 images, and the second raster has 1 image). I am using the loop function for multiplication. But I am not getting the results.
library(raster)
library(rgdal)
...
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74
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LISA clusters present very different values for the Low-Low quadrant. spdep x rgeoda
I am performing an Local Moran LISA clusters analysis using R package spdep. In some moment I compared the results with rgeoda package. OK if has some differ between them, different implementations, ...
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119
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Split a region into segments based on majority points
Having many points that belong to different classes (in the example below 9), I would like to split the region into multiple segments. In QGIS, the majority/minority tool does the job. In Python, ...
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17
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Unable to complete operation. Error executing tool DBSCAN_Cluster
Let me ask a question, I have a problem with the executable tool I built on arcgis. Before I published the tool it was running fine. However, when running through rest, an error appears.
import arcpy
...
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42
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How to change eps float value to geographic meter distance
I have a problem in making distance meter parameters for the DBSCAN tool. The problem is that I don't know the eps unit to use and how to change it to meters to be a parameter. Here's the Python ...
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366
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Cluster polygons into equal parts in QGIS
I have a large area divided into three parts. Each of these parts is divided into smaller parts. Each part contains an amount of biomass that can be cut and sold. The total amount of biomass in the ...
- 2,407
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310
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Create multiple callout lines from a single label
I would like to label groups of points (clusters) with only one label but several call-out lines. I built on top of the very appealing answer from @eurojam here: How do I give one label to two points?
...
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525
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Selecting points based on mutual distance and same attribute value using ArcGIS Pro
I have a layer of many points. From those, I need to select only those, that meet condition of having atleast two other points, in specified distance (lets say for example 100 meters) but where these ...
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261
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ClusterDBSCAN eps unit is meter or degrees if SRID is 4326
My SRID is 4326 for the points_geom column. Here is my code:
SELECT row_id, ST_ClusterDBSCAN(points_geom, eps := 100, minPoints := 5)
OVER(ORDER BY row_id) AS cluster_id FROM subset_cr
Am I ...
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224
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QGIS Clustering: Can I create heatmaps grouped by an attribute?
I've got some data that looks like this:
Where the relevant attributes is called pci (and sepearately a signal level). I'd like to create a separate heat map for each pci value (e.g. pci=18).
...
- 606
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46
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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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152
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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 ...
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130
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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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87
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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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674
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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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559
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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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147
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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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659
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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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80
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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 ...
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2
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498
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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 ...
- 269
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307
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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 ...
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218
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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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2
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152
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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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6
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230
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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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214
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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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51
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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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83
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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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118
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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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266
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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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184
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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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3
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428
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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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0
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165
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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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200
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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 ...
12
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1
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6k
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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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554
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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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285
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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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377
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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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131
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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 ...
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3
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1
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249
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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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168
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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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804
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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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2
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1k
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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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4
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1
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908
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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 ...
- 255
2
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183
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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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