Questions tagged [density]

A density map depicts a number of objects per unit area.

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48 views

Road density calculation

I have a vector layer of about 62km^2. I have a vector layer of roads within that area. How do I calculate the road density (km/km2)? I did a union between the road layer and the area layer, then I ...
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1answer
21 views

Compute area coverage density estimate from very large polygon dataset

I am trying to come up with a pipeline for turning very large OSM PBF files (eg buildings layer for a whole country: ~100M polygons) into a more manageable density estimate (with arbitrary precision). ...
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Population data to Population Density Raster Data

I'm currently using QGIS 3.16 for desktop. I have the population data of a district in excel ( number of inhabitants of a district) as well as openstreetmap raster. I am wondering if there is a way to ...
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51 views

How do you convert SpatialPoints object to PPP object?

I have a shapefile layer of polygons (houses in a city) that I want to run a kernel density on using the density() function in spatstat in R. To get my polygons as points I turned them into ...
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22 views

Seperate building-layer into buildings within villages and remote buildings using QGIS

im trying to seperate a building-layer into two layers. One layer should show the buildings within villages and the other one the remote buildings. My first approach was to buffer the buildings (and ...
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1answer
68 views

Area Density Heat Map QGIS

I would like to make a heat map of "building density" based on the area of the building footprints (I have them in a geojson as polygons) in relation to their "non-building" ...
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32 views

Point density with ModelBuilder

Now I have a lot of files that contain XY coordinates, like the picture, but this picture just contains one day. However, I want to integrate all the files I have. Secondly, I want to integrate all ...
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17 views

How do I show metrics (e.g., population density, counts, literacy rate) based on a custom polygon/shapes?

I currently have the GeoJSON files containing the census/administrative polygons and metrics associated with them. However, I want to add the ability to view that same data with custom polygons. For ...
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1answer
155 views

QGIS town label density

I'm composing a map of Big Island, Hawaii in QGIS 3.14.0 and would like to display major roads and cities + towns. Therefore I downloaded necessary information via QuickOSM. However, as many towns lie ...
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1answer
116 views

Stat_density_2d density plot seem to show too high density values for a small dataset

I'm working with a two-column data.frame with the columns containing x and y coordinates (Longitude, Latitude). A simple way to visualize a density map is by using the 'stat_density_2d' function. When ...
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2answers
155 views

Line density for mulitple commuters in QGIS

I have a layer with multiple lines, one city area commuting to another. This means that on some roads there are multiple lines lying on top of eachother, which at some point will split. I also have ...
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1answer
68 views

Sources for population density map of Europe

I want to make population density map for EU where I can show populations of people aged about 65yrs, where can I get a EU shapefile and population Excel file? Is there any EU shape file available ...
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How to output a raster of special case's distribution with regard to overall distribution?

For example, the crime scenes are unevenly distributed in a city. Each case's scene can be represented as a point. Thus, we can generate a raster map, which shows the crime scenes' density in this ...
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3answers
380 views

Population density: 1000 people/ km2

What does it mean when in certain publications they write population density (1000 people/km2)? Does it mean that they calculate the population density by dividing the number of people by the area of ...
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1answer
52 views

Calculating density within a shapefile (in R)

I'm trying to calculate density within a shapefile, but I'm fairly confident I'm doing it wrong. The idea is to figure out which geographical regions there have been the most sales by density. Here ...
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1answer
780 views

How to create density scatter plot from dataset for pairgrid in Python

I'm trying to compare the values of each pixel in relation to each band to create a scatter plot of density. First I extracted the values from the image to form an array, then I created a dataset. ...
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2answers
543 views

Choosing kernel density radius [closed]

I have 3 datasets with GPS points. Two of those are GPS points that represent boating activities (two different types) and the third represents turtle observations. I would like to perform Kernel ...
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35 views

Making density map based on number of hospitals in statistical area using ArcGIS Pro

I have the longitude and latitude of hospitals in Australia and I want to make a density plot (Symbology - graduated colours) to visualise the distribution of hospitals by a statistical area (defined ...
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84 views

Making informative legend for Kernel Density Estimate in QGIS?

I have used heatmap (kernel density estimation) in QGIS 3.0.1 to make a heatmap of boat counts. In my point data-each point is one boat. Then, in my kernel, I have used a 500m radius, with 500m pixel ...
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1answer
92 views

Producing density map in QGIS

I have placed a grid onto an open source Ordnance Survey map that corresponds to Ordnance Survey Eastings and Northings. I have a value for each grid square between zero and 30. How do I use these ...
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2answers
514 views

QGIS 3 building density calculations

I have layer of buildings (polygons), and in attribute table contains number of buildings, floor area of buildings etc. I would like to know how many buildings (#) is per Ha or km2, and building area ...
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1answer
47 views

Kernel Density Estimation Weighting Factor

I don't understand where is this weighting factor coming from, does it need to be in the quakeLyr in the attribute table named with "mag" or? # Now, we can run the kernel density estimation algorithm ...
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1answer
59 views

Converting Raster Density File into Point using ArcGIS Desktop?

I used the Point Density tool to create raster files. I plan on scaling these density values by dividing them by the greatest density value and then multiplying the result with a certain value that is ...
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1answer
318 views

Find EPS for DBSCAN

I have location posts from Instagram Data and want to cluster them by density - using DBSCAN. I played around quite a lot with different minPts and eps but never receive clusters (always one big ...
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29 views

Creating density map of roads for each district using ArcGIS Desktop?

I have to illustrate a map with the road density of each district. I have the city layer which comes with the bordered districts and another layer with all the roads. How can I create a density map ...
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34 views

Modification of Line Density using ArcGIS Desktop?

I am using ArcGIS Desktop 10.1. I need to calculate Line Density for polyline vector but the "Search radius" option must be replaced by something like the Neighborhood option in Focal Statistics. I ...
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42 views

Calculating route length per grid cell using fishnet

I have a problem determining the length of the routes (boat) I've surveyed in order to calculate the survey effort. I added the GPS points of the boat and then used the points to line tool and added a ...
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1answer
59 views

Site density related to river vicinity

I use ArcGIS 10.1. I have a shapefile with sites and another with the rivers of the area. I would like to calculate the density of the sites related to the river vicinity. Is it possible? Which type ...
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1answer
232 views

Identify most densely populated areas along streets with QGIS

On Google Satellite Imagery, I've created a layer with objects marking houses in a 1 km proximity to large streets in a rural setting using QGIS with the Openlayers Plugin. I would like to identify ...
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1answer
114 views

Finding output values of point density calculation?

I ran the point density tool and got an output, but because the 'Area Units' option in the Point Density was locked to Square_Map_Units - I don't know how to tell what units the density was calculated ...
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1answer
439 views

OpenLayers - Dot Density map

I'm trying to create a dot-density map with OpenLayers (OL) and GeoServer. I've a counties shapefile and I'm creating a vector layer in OL with county shapefile set as source for the vector layer. I ...
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2answers
732 views

Density map of pedestrian paths and footways in QGIS

I need to identify public places within pedestrian areas in London, so I need to calculate the density of both pedestrian links and footways. I have classified my data according to the categorization ...
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1answer
1k views

Creating species richness map (as next stage after species distribution)?

I'm using ArcMap. I've read the messages related to this topic but they don't take me far enough. Most of the advice is related to species distribution, but I need to create a species richness map. ...
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2answers
214 views

Uncertainty of a line between two coordinates with uncertainties in QGIS

I am trying to plot the uncertainty of a line between two coordinates with uncertainties. I have created polygons around 2 coordinates to represent the uncertainty region around each point. I then ...
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1answer
215 views

Calculate density of point feature class using field calculator? (not pop)

I'm just wondering what would be the best method to calculate density in the field calculator for a point shapefile (ArcMap). This wouldn't be based on a population value. I would need to derive a ...
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3answers
1k views

Creating population dot density map at the block group level in QGIS

I'm new to QGIS, always used ArcMap, and I'm struggling to find out how to best display population density at the block group level for a county (the most granular level of detail for census geography)...
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1answer
123 views

Creating linear density from points

I have a point layer from an aerial photographic survey of a savanna, where each point contains information on the number of trees found within each photo. Some points can have 0 trees, while other ...
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1answer
321 views

How can I set QGIS “Random Points” density to less than 0,0001 (circa 100 meters apart)?

I have an input boundary vector layer (700 hectares); on it, I want to generate a set of random points (Vector/Research tools/Random points) with a reciprocal distance average of 233 meters, but the ...
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192 views

Calculating built-up density for each cell in vector grid in QGIS?

I have two layers: a raster of India showing built-up areas (black pixels represent built areas) and a vector grid overlaying it. My goal is to calculate the percentage of built-up surface in each ...
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1answer
896 views

What does “layer units” mean?

I created a Shapefile from Google Earth (kmz) consisting of a set of points which I had used as a layer for Heatmap analysis. I opened the kmz file in QGIS and utilized the heatmap plug-in and it has ...
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0answers
107 views

Applying mask to Kriging shape in ArcGIS Desktop?

I'm trying to apply an mask to a Kriging image for after apply a Density Sampling Network, but unfortunately I'm not getting good results. I tried to apply on mask on Density Sampling Network and is ...
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37 views

How to interpret v.kernel network results

v.kernel "Optionally generates a vector density map on a vector network." I have done this for a network, but I don't understand how to interpret the output of this. Can anyone explain this? I am ...
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1answer
89 views

How can I transfer the values of a grid of smaller polygons to another grid with larger polygons in ArcGIS?

I have a population density grid containing 100x100m polygons. I would like to transfer the density values into an existing overlaying grid of larger polygons (250x250m). This might of course include ...
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5answers
4k views

Doing heatmap from line data in QGIS?

I want to perform a line density analysis for my line data, based on an attribute. The heatmap option (kernel density analysis) seems to be only possible for point data. I have tried to convert my ...
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2answers
632 views

Find average density value within a polygon in ArcMap

I've created a point density heat map for a city intended to show areas where there is more or less access to a certain type of public school. It would be useful to be able to identify which local ...
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1answer
206 views

Kernel Density Map points rejected as outside window

I am trying to make a kernel density plot of a points shapefile like so: library(rgdal) library(spatstat) library(maptools) points <- readOGR(dsn = "C:\\Documents", layer = "...
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1answer
940 views

Build Density Map for large dataset

I've got a postgre/postgis database with about 120 million positions (geography type). I would like to create a density map (e.g. a heatmap) and serve this via geoserver. I did create a one-band ...
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0answers
338 views

Reducing the density of points based on zoom level

I have a Polyline like the one shown in the example, representing the path of a vehicle. GeoJSON markers show the vehicle's position over time. How can I reduce the density of the markers when the ...
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1answer
1k views

Finding outlier point in set of points, by distance, using QGIS?

I need to identify and eliminate the outlier points in a set of points, as depicted below. It seems a simple task, but I cannot find the answer anywhere. I suspect that the proper way to go is ...
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0answers
407 views

Identifying activity places in GPS trajectories using R?

Is there a way in R (a script or package) that would allow identifying activity spots in GPS tracking data? I have a number of GPS tracks in GPX/CSV formats that follow the movements of people in a ...