Tagged Questions

Partitioning data points into subsets of objects according to their mutual "similarity," without using preexisting knowledge such as class labels.

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4
votes
0answers
19 views

Clusters of Same Size?

I am attempting to use the Grouping Analysis tool in the Spatial Statistics (in ArcGIS 10.2) to group state high schools (points) together based on enrollment and location. Is there a way to make ...
1
vote
0answers
17 views

Grouping map points into fixed cluster sizes? [duplicate]

"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 ...
1
vote
1answer
22 views

Leaflet/MarkerCluster plugin - how do update the HTML content of a DivIcon?

In Leaflet, I am using the markercluster plugin, in which you can use the DivIcon class to display custom icons for the clusters. You can set your own HTML for these clusters. However, I can't find ...
3
votes
1answer
109 views

How to create a cluster of crashes?

I have a shapefile with 52K points of road accidents, between 2007 and 2012. Each accident has a severity index. I want show clusters of 5 accidents (at least), for each year, that have a severity ...
1
vote
0answers
15 views

Creating single feature to represent group of individual features, based on location and #, using ArcGIS Desktop?

I am looking for an algorithmic way of handling this situation, as I can do it manually with the ruler and some time, but it would be nice to find a programmatic to have Arc do the work for me, so any ...
3
votes
1answer
60 views

How to find mean coordinates of a cluster of points from a point layer in QGIS?

I have a set of coordinate points. The points are distributed in such a way that some points are clustered around a specific area. There is an option to find out mean coordinates(s) of the whole point ...
11
votes
1answer
113 views

Identify points in a shapefile that have no other point within x km with QGIS

This is probably a naive question but I am struggling as a new user to QGIS. I have a very large shapefile (275,000 points, but can break this into about 10 subregions if necessary for faster ...
1
vote
0answers
36 views

Clustering the WGS84 point features (projection transformation aspects)

My question is quite trivial and was discussed many times before (like here) but in our case it has the confounding extra requirements... The list of sparsely distributed 2d point features is stored ...
0
votes
0answers
20 views

Clustering on Geoserver layer appearing out of the map

We are using Geoserver and openlayers to display maps. Geosever layer provides list of sites, since there were many we did a clsutering using Styles. But the problem is when we zoom out completely ...
1
vote
0answers
33 views

Finding areas with high POINT density from PostGIS table using Python

I have a PostGIS table with thousands of POINT objects and I want to find areas that have a high density of points. I have the DBSCAN clustering algorithm implemented in Python which does exactly ...
-3
votes
1answer
59 views

CartoDB Point Clustering?

I need to create clusters in Cartodb. I reffered to this code https://gist.github.com/andrewxhill/8695353. I am still getting an error. <!DOCTYPE html> <html lang="en"> <head> ...
1
vote
1answer
104 views

Get a single cluster from cloud of points with specified maximum diameter in postgis

I have on the order of 2M Geometry Collections with N (median: 2, stddev: 6.6, 75th: 6, 95th: 21) Point objects (repeated points allowed and important) in a PostGIS table. I want to identify clusters ...
2
votes
1answer
41 views

Clusters of points: Determining the centroid (QGIS)

I've basically got the same issue as this post, but can't find a way to transplant the ArcGIS solution to QGIS. I have household-level geo data for 10 villages spread out across the country. I need ...
0
votes
1answer
51 views

Cluster numbering in openlayers

I am using openlayers 2 for making clustering on vector point data for which I am a beginner. I have installed geoserver locally via opengeo suite and using 'world_cities' dataset as an example. I ...
2
votes
1answer
104 views

leaflet marker-cluster JSONP geoserver

I hope I can get same help from here. I started to put together a leaflet map, please see here: http://gis.xyz/leaflet2.html I want to show my postgis point (uk based) features on this map with ...
1
vote
0answers
47 views

Monte Carlo test of Space-Time clustering in R

I have several point patterns representing the distribution of territories of a bird species. Each point pattern represents the distribution of one year. I already succeeded in computing Ripley's L ...
1
vote
1answer
233 views

How to use Leaflet Marker Cluster on markers from Leaflet-layerJSON (Overpass API)

I'm having troubles getting the Leaflet Marker Cluster working with Leaflet-layerJSON. I'm trying to make a Leaflet map with data from OpenStreetMap. The markers are showing on the map, but they are ...
6
votes
1answer
139 views

How to get the centroid of a set of points in POSTGIS?

I use PostgreSQL with POSTGIS extension. I have a set of points in the_geom column from a table myshema.myobjects I would want create a select statement to get the centroid of this cluster, so from a ...
3
votes
0answers
28 views

Algorithm for estimating position of many objects and differentiating those?

Let's assume a crowd-sourced tree location use case where a research team asks hikers to GPS the location of a specific tree type in case they encounter it. This will lead to a large number of ...
0
votes
0answers
70 views

Creating a polygon around features

I want to create a polygon around a number of points so that all the points occur within the polygon. The purpose is to do this to a number of different features and see where they overlap.
0
votes
1answer
70 views

40k+ points from Shapefile, clustering them and populating on Google Maps/Webapp

I just started a new Python/Django webapp job related to GIS (and i'm totally new to GIS). Here is my task and what i have found so far, and i am stuck as to finding out what's the best way or the ...
2
votes
1answer
84 views

Do daytime Road Traffic Accidents (RTAs) have same spatial pattern as those of night?

With the following set of recorded data: Location of Road Traffic Accident (RTA) along 160km Expressway Date of accident Time of occurrence Causes of the accident etc What spatial analysis tool in ...
0
votes
0answers
88 views

Point Cluster Layer not defined

I am trying to do a point cluster layer based on the JSON objects I obtained from database. Here is my JavaScript to plot a point cluster layer: function addClusters() { $.ajax({ url: ...
2
votes
1answer
71 views

Maximize clusters of points from coordinate data

So I am definitely new to the GIS world, so bear with me if I don't know the best way to articulate my problem. That said, I am ready to learn, I would definitely welcome any direction that you all ...
4
votes
1answer
158 views

XYZ Clustering in Python and numpy arrays

I am looking for a method of clustering XYZ data in Python that works on numpy arrays. I know of a few sources, such as clusterpy and Pysal but have had little success with them as they seem to still ...
1
vote
1answer
139 views

Color region polygons according to cluster label

I want to present data on a map of our country. I have used R for showing the clusters on a country! Here the steps I took: setwd('D:/r/cluster2') channel <- odbcConnectExcel('cluster.xls') data ...
4
votes
2answers
101 views

Identify cluster centroids

I have a data set of points which are grouped into clusters like so: I'd like to use ArcGIS or Python to create a point layer of the centroids of each cluster but I can't seem to find the right ...
2
votes
2answers
73 views

Methods for hot spot or cluster analysis for multiple measurements at the same geographic unit?

I would like to find geographic clusters of zip codes where each zip code has a measurement of a person's age (integer), sex (categorical/binary), and if they recovered from a certain medical ...
0
votes
0answers
134 views

How do i integrate Clustering into my Google Map?

How do i integrate clustering for my google map? I have found a few codes but i'm not sure how to combine both so that it won't mess up the whole site. This is my current code: <script ...
0
votes
1answer
36 views

problem labelling cluster features in openlayers

I'm trying to label a vector layer with clustered points in OpenLayers. When the feature is clustered I want to show the value of an attribute of all the features included in the cluster. I've tried ...
0
votes
0answers
46 views

How to cluster points based on both proximity to each other and proximity to another layer (roads)?

Using QGIS I have managed to created cluster for points based on their proximity of each other (using buffer and spatial joins etc), but I would also like to add another variable to it: proximity to a ...
0
votes
0answers
12 views

Where are the settings that control when clustering starts and stops?

We have a SDE set up on a SQL Server and we're using the Silverlight API. Our layer has buildings on it. The flare clustering and large clusters show when the map is opened and the actual buildings ...
1
vote
0answers
74 views

Performing Moran Test using R? [closed]

I’m very new to R so please Bear with me: I have a set of data containing AREA Infested for each region ! and I want to know if there are any spatial autocorrelation between the regions! Here a sample ...
0
votes
0answers
31 views

Applying Spatial Clustering test using R? [duplicate]

I’m very new to R so please bear with me: I have a set of area infested by a disease (AIS) annually data and I want to apply some cluster methodology to detect regions with similar (AIS) patterns. I ...
0
votes
1answer
70 views

MYSQL 5.6 Cluster / chain points by distance to any other point without millions of calculations?

I have a table of approx 10,000 - 20,000 dynamic points across the globe stored as lon/lat points. I want to cluster any point within (roughly) 3km of any other point into one point (and return the ...
0
votes
0answers
92 views

Spiderfy Unclustering Effect in OpenLayers

I am looking for a good way to display multiple features (with custom marker icons) all located at the same location. At all zoom levels I need to be able to see all markers at a location either all ...
3
votes
1answer
112 views

Spatial Classification

I am not sure what to call my problem. From this image, I have a set of classified polygons (colored). I would like a way to classify the white polygons in the image. I don’t have any attributes to ...
0
votes
1answer
38 views

Error when running cluster and outlier analysis

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 utilize this tool: ...
1
vote
0answers
44 views

Getis-Ord GI and Moran's I when interested in clustering of data values not points

I have a dataset with many clustered (often coincident) points, each of which contains data. I am not interested in the fact that the points are obviously clustered. I would like to know whether the ...
0
votes
1answer
55 views

Self organizing maps with Postgis

I am trying to plot hot regions. It's reorganizing mapping We have a table "product" with three attributes : lat log n_items: number of items that we sell I'd like to group point in one polygon ...
1
vote
0answers
104 views

Leaflet marker cluster by Administrative boundary

Is it possible to perform clustering based on administrative boundary using the leaflet.markercluster plugin? How would I do that? I already have the boundary layer.
1
vote
1answer
118 views

How to cluster similar lines in PostGIS?

In PostGIS I have a large database of linestrings which I have obtained using ST_makeline function. I would like to cluster similar lines based on where the lines start and end. Here is an example ...
3
votes
2answers
295 views

How can I 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 ...
1
vote
1answer
112 views

How to disperse clusters of proportional markers or polygons?

I am mapping a set of points in ArcMap that are symbolized using proportional marker symbols based on a numeric field value. The scale of the map has lead to alot of the point markers overlapping. ...
0
votes
0answers
31 views

Finding a common area by a set of ID variables?

I am trying to find a way to find a way to get matches of areas based on multiple sets of ID variables. I am using state-county and state-puma as an example below, but I am wishing to do this for more ...
2
votes
1answer
77 views

Matching two point clouds without loss (nearest neighbor, but more complicated)

I have two point clouds, one with demographic and one with electoral data. Points in both clouds represent the same empirical entity (say, a village, or an urban neighbourhood), but are not in the ...
5
votes
1answer
161 views

How to grow several concave hulls until they completely fill a larger area without overlap?

This is my problem: I have a very large point layer with polling station locations across one country; each point belongs to a specific constituency (900k points, 4k constituencies). I wish to use ...
3
votes
1answer
100 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 this points automatically (not manually)? I don't want to ...
3
votes
0answers
125 views

Performing cluster analysis in R with Point Datasets

I am a R-Beginner, but I want to use it for some spatial statistics. I want to check the relation between the occurrence of ill persons and the existence of water in a area of interest. To give you a ...
1
vote
0answers
146 views

Is it possible to cluster markers based on city name in Google Maps API

I have a requirement to display all the customers in map. Since the customer list is too large it looks messy when I place markers. I have tried the marker cluster functionality but it groups based ...