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v.buffer.1grass

NAME

v.buffer - Creates a buffer around features of given type (areas must contain centroid).

KEYWORDS

vector, buffer

SYNOPSIS

v.buffer
v.buffer help
v.buffer [-sc] input=name output=name [type=string[,string,...]] [layer=integer] [distance=float] [minordistance=float] [angle=float] [bufcolumn=name] [scale=float] [tolerance=float] [debug=string] [buffer=float] [--overwrite] [--verbose] [--quiet]

Flags:

-s

Make outside corners straight

-c

Don't make caps at the ends of polylines

--overwrite

Allow output files to overwrite existing files

--verbose

Verbose module output

--quiet

Quiet module output

Parameters:

input=name

Name of input vector map

output=name

Name for output vector map

type=string[,string,...]

Feature type
Options: point,line,boundary,centroid,area
Default: point,line,area

layer=integer

Layer number
A single vector map can be connected to multiple database tables. This number determines which table to use.
Default: 1

distance=float

Buffer distance along major axis in map units

minordistance=float

Buffer distance along minor axis in map units

angle=float

Angle of major axis in degrees
Default: 0

bufcolumn=name

Name of column to use for buffer distances

scale=float

Scaling factor for attribute column values
Default: 1.0

tolerance=float

Maximum distance between theoretical arc and polygon segments as multiple of buffer
Default: 0.01

debug=string

This does nothing. It is retained for backwards compatibility

buffer=float

This is an alias to the distance option. It is retained for backwards compatibility
Buffer distance in map units

DESCRIPTION

v.buffer creates a buffer around features of given type, which have a category in the given layer. The tolerance controls the number of vector segments being generated (the smaller the value, the more vector segments are generated).

NOTES

Attributes are not transferred due to potential buffer overlap, which cannot be resolved automatically.

EXAMPLES

Buffer around input lines

v.buffer input=map output=buffer type=line distance=100

Circles around input points

v.buffer input=pointsmap output=circles type=point distance=1000

Non-overlapping circles around input points with attribute transfer

v.buffer input=archsites output=circles type=point distance=200
# change original points to centroids:
v.type in=archsites out=archcentroids type=point,centroid
# patch circles and centroids:
v.patch in=archcentroids,circles out=circles_db
# attach attributes, either use
# db.copy ...
# or link to the original table:
v.db.connect map=circles_db table=archsites field=1 key=cat driver=dbf \
database='$GISDBASE/$LOCATION_NAME/$MAPSET/dbf'

SEE ALSO

r.buffer, v.extract, v.type, v.patch, v.db.connect

AUTHORS

Radim Blazek
Rewritten by Rosen Matev (with support through the Google Summer of Code program 2008)

Last changed: $Date: 2008-03-16 16:29:33 +0100 (Sun, 16 Mar 2008) $

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© 2003-2010 GRASS Development Team