NAME

v.type - Changes type of vector features.

KEYWORDS

vector, geometry, editing, area, line, point

SYNOPSIS

v.type
v.type --help
v.type input=name [layer=string] output=name from_type=string to_type=string [--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 (’-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
from_type=string [required]: Feature type to convert from
Options: point, line, boundary, centroid, face, kernel
Default: line
to_type=string [required]: Feature type to convert to
Options: point, line, boundary, centroid, face, kernel
Default: boundary

DESCRIPTION

v.type changes the type of geometry primitives.

The following vector object types are defined in GRASS GIS:

point: a point;
line: a directed sequence of connected vertices with two endpoints called nodes;
boundary: the border line describing an area;
centroid: a point within a closed ring of boundaries;
area: the topological composition of a closed ring of boundaries and a centroid;
face: a 3D area;
kernel: a 3D centroid in a volume (not yet implemented);
volume: a 3D corpus, the topological composition of faces and kernel (not yet implemented).

Lines and boundaries can be composed of multiple vertices.

Area topology also holds information about isles. These isles are located within that area, not touching the boundaries of the outer area. Isles are holes inside the area, and can consist of one or more areas. They are used internally to maintain correct topology for areas.

EXAMPLES

Convert lines to area boundaries

v.type input=map_l output=map_b from_type=line to_type=boundary

In order to create areas, centroids must be added with v.centroids.

AUTHOR

Radim Blazek, ITC-Irst, Trento, Italy

SOURCE CODE

Available at: v.type source code (history)

Accessed: Tuesday Jun 30 11:42:34 2026