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

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2
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2answers
83 views

How do I create zones using location features? [closed]

I have a list of rock art sites with a recording of every image within each site. For example, Site 1 has 4 kudu, 1 lion, 3 males and a locust; Site 2 has 2 leopards, 1 elephant and 3 giraffes; Site 3 ...
0
votes
2answers
672 views

Identifying clusters of points within a given distance

So I have a database of lats/longs representing incidents occurring on or near roadways. My goal is to identify the street block areas with the highest number of incidents in the database. I don't ...
1
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0answers
386 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 ...
1
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0answers
166 views

Statistically compare two density maps?

I (will) have a modelled distribution and an observed distribution of animals. If I were to interpolate these position datasets to reflect some density distribution (perhaps using a kriging ...
-1
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2answers
125 views

City density in GIS [closed]

There's a cite calles 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 ...
7
votes
1answer
641 views

Creating contours with meaningful values from point data

I recently obtained a CSV containing the locations of all recorded bicycle accidents in Boston over the past few years. As an avid cyclist, I'd like to create a simple contour map that draws attention ...
1
vote
1answer
2k views

Python problems with select by attributes and user input

I am attempting to create a tool where the user can input a census tract number within the city of Plano (there are 77 tracts) and it ultimately creates a map layout showing the population density. I ...
0
votes
2answers
168 views

Count the area of rasterdata in specific shapefile polygons (residential density in different districts)

I'd like to count the exact area of three different residential classes (low, medium, high) by district of a shapefile which contains 225 districts. like: district 1 has: XXX sqm low, XXX sqm medium, ...
0
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0answers
633 views

How to fill in the parameters for kernel density estimation?

I am desperately trying to calculate animals home range with kernel. Unfortunately, the result is obviously incorrect and I cannot identify my mistake (I would like to post a screenshot but its not ...
0
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0answers
309 views

catchment delineation

I am trying to use qgis to delineate between three sub-sub-catchments. I have contour shape file of 20 meter height. Sub-catchment is about 12 square kilometers area but consist of three sub-sub-...
5
votes
1answer
350 views

Adding kernel density output to map with ArcPy

I am trying to emulate the behavior of the Kernel Density tool from the ArcMap 10 GUI in a script; in other words, I want to calculate the density of a dataset, and add the visual result to a map. If ...
3
votes
1answer
111 views

V.kernel not working correctly in grass-6.4.2

I am using grass-6.4.2 for generation of heat maps of crime data. For testing purpose, I created a vector layer from my places shapefile which is a point data.The places shapefile contains more than ...
8
votes
1answer
649 views

How to create a Human Trafficking Heatmap in QGIS?

I'm trying to create a heatmap with about 325 points distributed around the city of Houston. (FYI Houston is a major human trafficking in the US: a title shared with LA and Atlanta depending upon ...
1
vote
0answers
52 views

how can i plot news stories to show how many stories include each country on a map of the world

We have a table that shows the number of news stories that include particular countries over a set period of time there are three news channels that we have this data for and we would like to show/ ...
1
vote
0answers
322 views

How to calculate the density of settlement per 100 square kilometers?

I have a point shapefile representing settlements. I want to calculate the density of settlement per 100 square kilometers. Should I use point or kernel density? I am working with ArcGIS. Is there any ...
9
votes
1answer
5k views

Dot Density Maps in QGIS?

Is there a 'friendly' way to create dot-density maps, where a polygon attribute data defines the number of dots (e.g. 1 dot = 100 ) using QGIS 1.7+? I say friendly because after a couple of hours ...
12
votes
1answer
2k views

How do you use GRASS's v.kernel?

I am flummoxed on how to use GRASS's v.kernel. I have a vector layer of around 2.5 million points. I want to make a heat map using v.kernel to show concentrations, since I have variable instances ...
5
votes
1answer
417 views

Finding nodes with QGIS

As part of work in statistical mapping for school, I need to use QGIS to find the spatial extent of commercial nodes. A node is defined for this exercise as a zone of 75m in diameter where the ...
3
votes
2answers
758 views

Determine density or cover from a raster layer that has been clipped by a polygon

I am a very new GIS user using ArcMap 10. I have a raster layer of tree canopy that I have clipped so that the layer is in a polygon that is a circle with a 2km radius. I have done this for four ...
5
votes
1answer
2k views

How to produce density map in square kilometers?

I have a shp file with the location (lat, lon) of lightning spatial distribution. I want to produce a density map of lightning occurrence per square KM. I used density point function and I don't know ...
6
votes
2answers
623 views

How to redistribute population data using Python in ArcGIS?

I am trying to redistribute population data from census centroids among to housing density.Would you please help me to do that? I do have census area centroids (points) and the boundaries belong to ...
11
votes
6answers
2k views

How do I make a heat or Choropleth map that uses polygons in QGis?

I've been playing around with the heatmap plugin for QGIS and I am wondering if it is possible to make heatmap with using a similar plugin/tool that uses polygons as well as points? I would like to ...
6
votes
2answers
355 views

How do I compute v.kernel maps in less than 16 hours?

I am using the GRASS GIS 6.4.2 bundled with QGIS 1.8.0, using a PostGIS dataset exported via v.in.org.qgis from QGIS, to create kernel density maps. The layer has 738,288 points. My problem is the ...
5
votes
1answer
4k views

How to do Kernel density analysis in QGIS 1.7?

Do someone have some suggestion? We would like to tray Kernel Density analysis as we did with ArcGis using QGIS?
15
votes
6answers
7k views

What's the best way to produce a density map from weighted points in QGIS?

I'd really like to repeat the functionality of the ArcGIS Kernel Density tool - how could I do that? I would like to limit answers to easy-to-install free-and-open-source software – i.e. QGIS ...
8
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3answers
3k views

Is population density considered continuous data and why?

Population counts are typically referred to as discrete or quantitative data. Why is population density a continuous data type when it is typically measured for aggregate areas such as census tracts ...
2
votes
0answers
372 views

kernel density with Grass-Qgis

Hello I am studying the use of GRASS GIS within Qgis and I need a little help with the understanding of the v.kernel module. I didn't find any human help within the manual (very cryptic) This are my ...
8
votes
1answer
1k 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 ...
4
votes
1answer
3k views

calculate building density in ArcMap

I have two questions related to calculate building density. I need to calculate the building density in a map which Data is in shape format. The buildings and the area are in two different layers. ...
7
votes
1answer
1k views

How to calculate Line Density in QGIS?

I have a map of fracture distributions over an area and I would like to calculate the density distribution of fractures that intersect a moving window with a specified radius. Is there a way to ...
4
votes
1answer
505 views

Finding intersection density for weighted lines connecting points across the continental USA

I'm working on an one-time problem that I'm hoping to solve with a computer program using free GIS libraries (preferably for VB.Net, C#, or Python... Java or C/C++ could work too). Alternatively, I ...
6
votes
2answers
8k views

Interpretation of ArcGIS Kernel Density legend parameters

In ArcMap 9.3 I've used Kernel Density to map various incidents, but the resulting shapefile doesn't display any units of measurement. Is there a good, not-to-technical source that would explain in ...
6
votes
1answer
545 views

Normalizing and adding kernel density rasters

I have 4 years of road kill data for one road, though each year has a different sample time frame (i.e. May-June vs. April-October) and therefore each year has a different number of surveys and totals ...
8
votes
2answers
3k views

Spatial statistics tools : clustering analysis on raster data

I've an apparently simple problem, but i can't find a clear methodology to use. I'm tasked to delimit "urban areas" by vector convex polygons, using the Gridded Population of the World dataset from ...