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v.kernel

NAME

v.kernel - Generates a raster density map from vector points data using a moving 2D isotropic Gaussian kernel or optionally generates a vector density map on vector network with a 1D kernel.

KEYWORDS

vector, kernel density

SYNOPSIS

v.kernel
v.kernel help
v.kernel [-oqv] input=name [net=name] output=name stddeviation=float [dsize=float] [segmax=float] [distmax=float] [mult=float] [--verbose] [--quiet]

Flags:

-o

Try to calculate an optimal standard deviation with 'stddeviation' taken as maximum (experimental)

-q

Only calculate optimal standard deviation and exit (no map is written)

-v

Run verbosely

--verbose

Verbose module output

--quiet

Quiet module output

Parameters:

input=name

Input vector with training points

net=name

Input network vector map

output=name

Output raster/vector map

stddeviation=float

Standard deviation in map units

dsize=float

Discretization error in map units
Default: 0.

segmax=float

Maximum length of segment on network
Default: 100.

distmax=float

Maximum distance from point to network
Default: 100.

mult=float

Multiply the density result by this number
Default: 1.

DESCRIPTION

Generates a raster density map from vector points data using a moving 2D isotropic Gaussian kernel or optionally generates a vector density map on vector network with a 1D kernel.

NOTES

The mult option is needed to overcome the limitation that the resulting density in case of a vector map output is stored as category (Integer). The density result stored as category may be multiplied by this number.

With the -o flag (experimental) the command tries to calculate an optimal standard deviation. The value of stddeviation is taken as maximum value. Standard deviation is calculated using ALL points, not just those in the current region.

LIMITATIONS

The modules only considers the presence of point, but not (yet) any attribute values.

SEE ALSO

v.surf.rst

AUTHOR

Stefano Menegon, ITC-irst, Trento, Italy
Radim Blazek (network part)

Last changed: $Date: 2005-01-11 11:23:39 +0100 (Tue, 11 Jan 2005) $

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