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Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.

NAME

r.out.kde - Exports raster with variable transparency into an image file

KEYWORDS

raster, kernel density, visualization, transparency, heatmap

SYNOPSIS

r.out.kde
r.out.kde --help
r.out.kde input=name background=name output=name [method=string] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--ui
Force launching GUI dialog

Parameters:

input=name [required]
Raster map to be rendered with semi-transparency
background=name [required]
Background raster map
output=name [required]
Rendered output file
method=string
Method to scale transparency
Options: linear, logistic

Table of contents

DESCRIPTION

r.out.kde creates an image file (e.g., PNG, JPG, or GIF) where the input raster is rendered on top of background raster with varying transparency based on the values of the input raster. This can be used for example for visualization of kernel density estimate (KDE).

With logistic method, values are scaled so that lower values are more transparent and higher values are more opaque than with linear scaling.

This module requires Python Imaging Library (already required for GRASS GIS).

EXAMPLE

In this example, we visualize KDE of schools on top of shaded relief map.
g.region raster=elevation
# create background map
r.relief input=elevation output=relief
# compute kernel density estimate
v.kernel input=schools_wake output=schools_density radius=4000 multiplier=1000000
r.colors map=schools_density color=bcyr
r.out.kde input=schools_density background=relief method=logistic output=output.png

SEE ALSO

d.rast, v.kernel

Logistic function

AUTHORS

Anna Petrasova, NCSU GeoForAll lab

SOURCE CODE

Available at: r.out.kde source code (history)

Latest change: Mon Jun 28 07:54:09 2021 in commit: 1cfc0af029a35a5d6c7dae5ca7204d0eb85dbc55


Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.

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