Questions tagged [density]

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

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2answers
429 views

Trying to measure point density along a line

I have a dataset that consists of animal sightings along a road and I want to calculate the density of points (sightings) along that road. My primary goal is to measure sighting hot spots, but I also ...
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1answer
44 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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2answers
223 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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16 views

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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1answer
62 views

Producing density map using 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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3answers
108 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
57 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
38 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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2answers
439 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
669 views

Percent coverage of a polygon in a raster grid

I have a wooded area polygon and a study area grid of cells with 300m resolution. I would like to calculate a raster which shows the amount of each grid cell covered by the polygon. The density per ...
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1answer
110 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
160 views

Calculating city density in GIS [closed]

There's a city called http://map.vmr.gov.ua/ in which each house has a type (for living, offices etc) and number of floors. I want to find out city density - i.e. to assign certain amount of people ...
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2answers
150 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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1answer
189 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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0answers
29 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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2answers
493 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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0answers
49 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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6answers
5k views

Identifying true curves/arcs in ArcMap?

The only good way of creating circles in ArcMap is using true arc, (compound curves) but I need to convert those to vertex (densifying) because of a compatibility problem. I need info for geodatabase ...
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24 views

Kernel Density Estimation Weighting Factor

I dont 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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2answers
14k views

Creating density map from point data in ArcGIS Desktop?

I have point data, where one point represents one 1 storm water outfall, looks like this: (point data is across all of Long Island, New York). I am having a bit of difficulty finding the best tool ...
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0answers
27 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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2answers
1k views

Density analysis producing extreme values?

I have point data of gas flares and I am trying to create a simple density raster of those flares. Results are either 0 or in the 100,000-1,000,000 range (when there's 5 to 40 or so points in each box)...
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0answers
97 views

Summing Raster cells to equal circles with specific sum using ArcMap? [closed]

I have application user density data that I've collected. Each gps point has a user density associated with it (for example: 150 users within a 1 km radius, which calculates to users/[pi*R-sq] OR 47....
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0answers
31 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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1answer
4k views

How to make a density map from polygons/rasters (ArcGIS)

I would like to make a density map of grasslands. I have a vector layer of habitat classifications, I would like to a density map of grasslands within a specified radius. My thoughts are to: ...
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0answers
37 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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2answers
503 views

Calculating density map of cycleways using fishnet in ArcGIS Desktop?

How can I calculate density map of cycleways (line feature) which refers to net grid in ArcGIS? Result by using function Line Density in ArcGIS for me is not satisyfing. I created reference grid net ...
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2answers
2k views

What type of kernel density function does ArcMap use?

I know that there are several types of kernel density functions, such as uniform, cosine, Gaussian, etc. I was just wondering which one the "Kernel Density" functionality in ArcMap 10's Spatial ...
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0answers
877 views

Trying to Create a Global Choropleth Population Density Map then add Biodiversity Level

I am trying, quite unsuccessfully, to create a global choropleth population density map for a specific 120 countries, using ggplot2. Once I have created this choropleth map, I want to add number of ...
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2answers
178 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
154 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
164 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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1answer
104 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
309 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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1answer
124 views

Density Slicing of MODIS Raster

I have some MODIS data processed with MRT tools. They are now in tiff format. Now, I have to complete Density slicing to identify water pixels from the image. The DN higher than 1985 is usually non-...
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1answer
726 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
744 views

Getting quantity of intersecting lines of polygons in QGIS?

im looking for a way to get the quantity of lines from a line-layer that intersect the different polygons of a polygon-layer; I have: One line-layer with a clutter of lines, defined by ID, which ...
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2answers
754 views

Creating a 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
1k views

Kernel vs Point density [closed]

Can someone give me an example each where these two tools would be appropriate to use. I kind of understood what each of them does but can't seem to figure out examples where one would be more ...
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1answer
273 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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1answer
101 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
322 views

Arguments error when running LineDensity scripts in arcpy [closed]

I'm trying to use LineDensity tool on polyline features. The shapefile is small and includes some invalid geometries. The code I use is an adaptation of an ArcGIS Help script. Here is my code: ...
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0answers
177 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
789 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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2answers
2k views

Line density map in QGIS [duplicate]

I would like create something like that in QGIS: http://2.bp.blogspot.com/--EFSaghZ92s/VqQXXIoE4AI/AAAAAAAABKw/KGkoB8zZ6K8/s640/scs2%2Bmap.jpg I have a huge amount of points and I can import in QGIS (...
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3answers
3k 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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0answers
98 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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0answers
33 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
47 views

QGIS Grid Union Issues

I am trying to create a choropleth map of ice concentration over Lake Erie. I have data for all the lakes (I can clip it all at the end), which are in a point shapefile. I have laid a grid over the ...
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1answer
76 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 ...