GRASS GIS manual: v.split

Note: A new GRASS GIS stable version has been released: GRASS GIS 7.6, available here.
Updated manual page: here

NAME

v.split - Splits vector lines to shorter segments.

KEYWORDS

vector, geometry, densification, node, segment, vertex

SYNOPSIS

v.split

v.split --help

v.split [-nf] input=name [layer=string] output=name [length=float] [units=string] [vertices=integer] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-n: Add new vertices, but do not split; Applies only to 'length' option
-f: Force segments to be exactly of given length, except for last one; Applies only to 'length' option
--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 ('-1' for all layers); A single vector map can be connected to multiple database tables. This number determines which table to use. When used with direct OGR access this is the layer name.; Default: -1
output=name [required]: Name for output vector map
length=float: Maximum segment length
units=string: Length units; Options: map, meters, kilometers, feet, surveyfeet, miles, nautmiles; Default: map
vertices=integer: Maximum number of vertices in segment

DESCRIPTION
EXAMPLES
- Example 1: Inserting nodes to railroad lines map
- Example 2: Inserting vertices to railroad lines map
SEE ALSO
AUTHOR

DESCRIPTION

v.split splits vector lines into shorter segments using a maximal distance between nodes. The resulting length of all segments is expected to be equal and not higher than the given length parameter.

EXAMPLES

The examples are based on the North Carolina sample data location.

Example 1: Inserting nodes to railroad lines map

# extract one railroad line for this example
v.extract input=railroads output=myrr cats=1

# show line, category, direction (to find the beginning)
g.region vector=myrr
d.erase
d.vect myrr display=shape,cat,dir

# insert nodes at a distance not longer than 1000m
v.split input=myrr output=myrr_split_1km length=1000

d.vect myrr_split_1km display=shape,topo

Note: In case that the vector line data are not polylines, generate first polylines as the second step, eg.:

# join segments into polyline
v.build.polylines input=myrr output=myrr_polylines
# regenerate categories
v.category input=myrr_polylines output=myrailroads option=add

Example 2: Inserting vertices to railroad lines map

Note: first run the two steps from example 1.

# insert vertices at a distance not longer than 1000m
v.split -n input=myrr output=myrr_split length=1000
d.vect myrr_split display=shape,topo

AUTHOR

Radim Blazek

Last changed: $Date: 2016-03-10 09:02:58 -0800 (Thu, 10 Mar 2016) $

SOURCE CODE

Available at: v.split source code (history)