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
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).
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
d.rast,
v.kernel
Logistic function
Anna Petrasova,
NCSU GeoForAll Lab
SOURCE CODE
Available at:
r.out.kde source code
(history)
Latest change: Tuesday Nov 05 09:35:47 2024 in commit: f00067506253c89598cffadc3c7fa07cff7233fd
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GRASS Development Team,
GRASS GIS 8.4.1dev Reference Manual