Ubuntu Manpage: r3.neighbors - Makes each voxel value a function of the values assigned to the voxels around it, and

Provided by: grass-doc_7.8.2-1build3_all

NAME

       r3.neighbors   -  Makes  each  voxel value a function of the values assigned to the voxels around it, and
       stores new voxel values in an output 3D raster map

KEYWORDS

       raster3d, algebra, voxel, statistics, aggregation, neighbor, focal statistics, filter

SYNOPSIS

       r3.neighbors
       r3.neighbors --help
       r3.neighbors  input=name  output=name  method=string    [quantile=float]    window=x,y,z    [--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]
           Name of input 3D raster map

       output=name [required]
           Name for output 3D raster map

       method=string [required]
           Aggregate operation
           Options:  average,  median,  mode,  minimum, maximum, range, stddev, sum, count, variance, diversity,
           interspersion, quart1, quart3, perc90, quantile

       quantile=float
           Quantile to calculate for method=quantile
           Options: 0.0-1.0

       window=x,y,z [required]
           The size of the window in x, y and z direction, values must be odd integer numbers, eg: 3,3,3

DESCRIPTION

r3.neighbors looks at each voxel in a 3D raster input map layer, and examines the values assigned to the
voxel in a user-defined "neighborhood" around it. It outputs a new 3D raster map in which each voxel is
assigned a value that is a (user-specified) function of the values in that voxel’s neighborhood. For
example, each voxel in the output map might be assigned a value equal to the average of the values
appearing in its 3 x 3 x 3 voxel "neighborhood" in the input map layer.

OPTIONS
The user must specify the names of the 3D raster map layers to be used for input and output, the method
used to analyze neighborhood values (i.e., the neighborhood function or operation to be performed), and
the moving window of the neighborhood.

Neighborhood Operation Methods: The neighborhood operators determine what new value a center voxel in a
neighborhood will have after examining values inside its neighboring voxels. Each voxel in a 3D raster
map layer becomes the center voxel of a neighborhood as the neighborhood window moves from voxel to voxel
throughout the map layer. r3.neighbors can perform the following operations:

average
The average value within the neighborhood.

median
The value found half-way through a list of the neighborhood’s values, when these are ranged in
numerical order.

mode
The most frequently occurring value in the neighborhood.

minimum
The minimum value within the neighborhood.

maximum
The maximum value within the neighborhood.

range
The range value within the neighborhood.

stddev
The statistical standard deviation of values within the neighborhood.

sum
The sum of values within the neighborhood.

variance
The statistical variance of values within the neighborhood.

diversity
The number of different values within the neighborhood.

interspersion
The percentage of voxels containing values which differ from the values assigned to the center voxel
in the neighborhood, plus 1.

Neighborhood Size: The neighborhood moving window specifies which voxel surrounding any given voxel fall
into the neighborhood for that voxel. The window must be three comma separated odd integers. The
dimension order is: x,y,z. For example: the parameter window=3,3,3 specifies a moving window (a cube)
with 27 voxel.

NOTES

       The r3.neighbors program works in the current geographic region.  It is recommended,  but  not  required,
       that the 3D resolution of the geographic region be the same as that of the 3D raster map layer.

       r3.neighbors  doesn’t  propagate  NULLs,  but  computes  the  aggregation over the non-NULL voxels in the
       neighborhood.

AUTHOR

       Soeren Gebbert

SOURCE CODE

       Available at: r3.neighbors source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual