A density map depicts a number of objects per unit area.
5
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3answers
783 views
How to interpret GRASS v.kernel results?
GRASS manual reads:
v.kernel - Generates a raster density map from vector points data using a moving 2D isotropic Gaussian kernel ...
Ok, but how do I interpret the results? I understand that ...
11
votes
1answer
908 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 ...
6
votes
2answers
1k 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 ...
2
votes
0answers
117 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 ...
3
votes
2answers
105 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 ...
3
votes
2answers
2k 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 ...
2
votes
1answer
172 views
How to Calculate Utilization Distribution Overlap Index (UDOI) in ArcGIS 10?
I was wondering if any of you happen to have any information on how to calculate the Utilization Distribution Overlap Index (UDOI) in ArcGIS 10? If I understand it correctly the UDOI takes two kernel ...
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votes
0answers
150 views
Is there a tool that tells how many features there are within a set distance in ArcView?
I'm looking to create a raster, in ArcView, that represents how many features (either points or polygons) are within a certain distance from any given location within a study area. I know there must ...
6
votes
2answers
196 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
959 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?
