## table of contents

r3.neighbors(1grass) | GRASS GIS User's Manual | r3.neighbors(1grass) |

# 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.

# SEE ALSO¶

*g.region,* *r.neighbors,* *r3.mapcalc,*
*r3.stats,* *r3.support*

# AUTHOR¶

Soeren Gebbert

# SOURCE CODE¶

Available at: r3.neighbors source code (history)

Accessed: Saturday Jul 27 17:08:36 2024

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