v.split.1grass man page

v.split — Splits vector lines to shorter segments.

Keywords

vector, geometry, densification, node, segment, vertex

Synopsis

v.split
v.split --help
v.split [-n] 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
--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

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

See Also

v.edit, v.build.polylines, v.to.points, v.segment

Author

Radim Blazek

Last changed: $Date: 2016-03-10 18:03:32 +0100 (Thu, 10 Mar 2016) $

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GRASS 7.0.4 Grass User's Manual