r3.neighborsgrass - Online in the Cloud

PROGRAM:

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.

Use r3.neighborsgrass online using onworks.net services