Questions tagged [spatial-cluster]

Use this tag when referring to spatial clustering in GIS.

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11
votes
1answer
2k views

Raster clustering using QGIS

I'm looking for a way to convert a classified raster into polygons based on spatial clusters within each class. For the clusters to be considered as valid I need them to consist of a minimum ...
6
votes
1answer
2k 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 ...
6
votes
1answer
2k views

Seeking Fréchet distance implementation (Python) to cluster trajectories by similarity

I am working on a trajectory analysis project using Python and its data science related libraries. I am planning to implement Fréchet distance algorithm for trajectory analysis, each trajectory has ...
6
votes
1answer
989 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.
5
votes
2answers
1k views

Point cluster in ArcGIS Javascript API 4.3?

I am trying to create a map with the the ArcGIS API for JavaScript v4.3. Some of the points that I want to visualize are on the same location and I would like to use some type of point clustering to ...
4
votes
1answer
84 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 ...
4
votes
1answer
2k views

python cluster Points with DBSCAN keeping into account Polygon boundaries

I have a GeoPandas dataframe called geo containing: 431978 unique spatial Points representing all households in a city. 112737 Polygons representing all the premises (panden) in a city dataframe ...
4
votes
0answers
218 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 ...
4
votes
0answers
2k views

Clustering of events within a space-time window (R)

I am relatively new to clustering methods and am trying to determine the best method for clustering (or merely grouping) events that fall within a space-time window using preferably R. My goal is to ...
3
votes
1answer
2k views

Understanding ST_ClusterWithin

I am trying to create a map which shows points that are clustered (or not depending on the distance between the points). So, I have the following query: SELECT ST_NumGeometries(gc) as ...
3
votes
2answers
397 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 ...
3
votes
1answer
97 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 ...
3
votes
1answer
139 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 ...
3
votes
1answer
108 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 ...
3
votes
1answer
2k views

Run spatial clustering by inputting coordinates to cluster algorithm

I've been reading about algorithms for spatial clustering and it's easy to get lost since there are dozens of them. An idea that came to my mind is to use an a-spatial cluster algorithm on a dataset ...
3
votes
1answer
26 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-...
3
votes
1answer
105 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 ...
3
votes
1answer
612 views

Spatial clustering points on a spatial network in QGIS / PostGIS

I have some thousands of houses/addresses (points) and a road network and I would like to build clusters of defined minimum to maximum cluster size not using euclidean distance as a metric, but the ...
3
votes
0answers
73 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 ...
3
votes
0answers
843 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, ...
2
votes
1answer
249 views

Dissolving polygons on distance condition using PostGIS?

I'm tying to group some polygons in same layer, on geometry & attribute conditions: within 0.8m from each other and with same value in a column. With answers I've found here I've got something ...
2
votes
1answer
137 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 ...
2
votes
1answer
39 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 ...
2
votes
1answer
383 views

How to use ST_Contains() with ST_ClusterWithin()

I need to write a spatial query which will return centroids of clusters which are within a bounding box or polygon. The query I have now is: SELECT ST_NumGeometries(unnest(ST_ClusterWithin(...
2
votes
1answer
24 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 ...
2
votes
1answer
94 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 ...
2
votes
1answer
755 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 ...
2
votes
1answer
211 views

Cluster analysis for different plant species with elevation, aspect, slope rasters using ArcGIS Desktop?

I am using ArcGIS Desktop. I have a point shapefile for 5 different plant species and rasters (elevation, slope, aspect, canopy height). I am trying to find clusters for each species in terms of ...
2
votes
0answers
48 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 ...
2
votes
0answers
127 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 ...
2
votes
1answer
205 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 ...
2
votes
0answers
167 views

GIS Clustering with drawing predefined square area around points as cluster boundaries

I have a layer of points and I would like to create clusters where a predefined square area of 5km by 5km is the boundary for the cluster. Is there a way to iteratively draw square polygons around ...
2
votes
0answers
353 views

Use QuadTree in R to create Geospatial clusters [closed]

I am currently looking into different clustering techniques to form clusters from geospatial data. Is it possible to utilize quadtrees(from the SearchTrees package in R) to come up with something ...
2
votes
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 ...
1
vote
1answer
55 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 ...
1
vote
1answer
95 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 ...
1
vote
1answer
436 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 ...
1
vote
2answers
465 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 ...
1
vote
1answer
162 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 ...
1
vote
1answer
95 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 ...
1
vote
1answer
249 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 ...
1
vote
1answer
245 views

Generate spatial weight matrix from file in ArcGIS

I am trying to create a spatial weight matrix from an existing file in ArcGIS. I need to use another file, as opposed to generate the weights in Arc, because I define non-standard weights. The ...
1
vote
1answer
177 views

Maximising cluster density around geo points using qgis

I am looking for some advice for clustering points around other defined centres while maximising the density i.e. I need to identify clusters but constrain the cluster densities to be >= ...
1
vote
0answers
20 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 ...
1
vote
0answers
98 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 ...
1
vote
0answers
344 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 ...
1
vote
0answers
204 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 ...
1
vote
0answers
518 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 ...
1
vote
0answers
51 views

Find cluster of points within a 14K dataset which are laying within a circle of a certain radius

I have a dataset of geolocated points, which are dispersed over a large area I need to find clusters of a minimum number of X points within these sets which are laying within a circle of which the ...
0
votes
1answer
869 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 ...