NAME

       v.neighbors  - Neighborhood analysis tool for vector point maps.
       Makes  each cell value a function of the attribute values assigned to the vector points or
       centroids in a radius around it, and stores new cell values in an output raster map.

KEYWORDS

       vector, algebra, statistics, raster, aggregation

SYNOPSIS

       v.neighbors
       v.neighbors --help
       v.neighbors   input=name     [layer=string]     output=name    method=string    size=float
       [points_column=name]      [cats=range]     [where=sql_query]     [--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 vector map
           Or data source for direct OGR access

       layer=string
           Layer number or name
           Vector features can have category values in different layers. This  number  determines
           which layer to use. When used with direct OGR access this is the layer name.
           Default: 1

       output=name [required]
           Name for output raster map

       method=string [required]
           Method for aggregate statistics (count if non given)
           Options: count, sum, average, median, mode, minimum, maximum, range, stddev, variance,
           diversity
           Default: count

       size=float [required]
           Neighborhood diameter in map units

       points_column=name
           Column name of points map to use for statistics
           Column of points map must be numeric

       cats=range
           Category values
           Example: 1,3,7-9,13

       where=sql_query
           WHERE conditions of SQL statement without ’where’ keyword
           Example: income < 1000 and population >= 10000

DESCRIPTION

       This module makes each cell value a function of  the  attribute  values  assigned  to  the
       vector  points  or centroids in an area around the cell with a diameter of size around it,
       and stores the new cell values in the output raster map layer. By default, the module just
       counts  the  number  of  points.  The  user can also choose amongst a variety of aggregate
       statistics using the parameter method. These statistics are calculated on  the  attributes
       in  the point_column. Using the usual cats and where parameters the user can chose to take
       only a subset of the points into account.

       Note that size is defined as the diameter, and so  has  to  be  twice  the  wanted  search
       radius,  and  that  the  module works within the current computational region which can be
       adjusted using g.region. If the vector map falls completely outside  the  current  region,
       the module will stop with an error.

EXAMPLE

       Count the number of schools for a given grid (North Carolina sample dataset):
       g.region vector=schools_wake res=100 -p -a
       v.neighbors input=schools_wake output=schools_wake_3000m method=count size=3000
       d.mon wx0
       d.rast schools_wake_3000m
       d.vect schools_wake
       The  result gives for each grid cell the number of points (here: schools) not farther than
       1500 meter away (half of the given size value) from the respective cell center.

       Calculate the mean capacity of schools for the same grid:
       v.neighbors input=schools_wake output=schools_capacity point_column=CAPACITYTO \
                   method=average size=3000

SEE ALSO

        r.neighbors, v.vect.stats

AUTHORS

       Radim Blazek,
       Moritz Lennert

SOURCE CODE

       Available at: v.neighbors source code (history)

       Accessed: Tuesday Jun 27 11:13:52 2023

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       © 2003-2023 GRASS Development Team, GRASS GIS 8.3.0 Reference Manual