GRASS GIS 6.4.svn Reference Manual: vector

GRASS GIS 6.4.svn Reference Manual

Geographic Resources Analysis Support System, commonly referred to as GRASS, is a Geographic Information System (GIS) used for geospatial data management and analysis, image processing, graphics/maps production, spatial modeling, and visualization. GRASS is currently used in academic and commercial settings around the world, as well as by many governmental agencies and environmental consulting companies.

This reference manual details the use of modules distributed with Geographic Resources Analysis Support System (GRASS), an open source (GNU GPL'ed), image processing and geographic information system (GIS).

Quick Introduction

vector commands:

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

v.build.all Rebuilds topology on all vector maps in the current mapset.

v.build Creates topology for GRASS vector map.

v.build.polylines Builds polylines from lines or boundaries.

v.category Attach, delete or report vector categories to map geometry.

v.centroids Adds missing centroids to closed boundaries.

v.clean Toolset for cleaning topology of vector map.

v.convert.all Convert all old GRASS < Ver5.7 vector maps in current mapset to current format

v.convert Imports older versions of GRASS vector maps.

v.db.addcol Adds one or more columns to the attribute table connected to a given vector map.

v.db.addtable Creates and adds a new attribute table to a given layer of an existing vector map.

v.db.connect Prints/sets DB connection for a vector map to attribute table.

v.db.dropcol Drops a column from the attribute table connected to a given vector map.

v.db.droptable Removes existing attribute table of a vector map.

v.db.join Allows to join a table to a vector map table.

v.db.reconnect.all Reconnects vectors to a new database.

v.db.renamecol Renames a column in the attribute table connected to a given vector map.

v.db.select Prints vector map attributes.

v.db.univar Calculates univariate statistics on selected table column for a GRASS vector map.

v.db.update Allows to update a column in the attribute table connected to a vector map.

v.delaunay Creates a Delaunay triangulation from an input vector map containing points or centroids.

v.digit Interactive editing and digitization of vector maps.

v.dissolve Dissolves boundaries between adjacent areas sharing a common category number or attribute.

v.distance Finds the nearest element in vector map 'to' for elements in vector map 'from'.

v.drape Converts vector map to 3D by sampling of elevation raster map.

v.edit Edits a vector map, allows adding, deleting and modifying selected vector features.

v.external Creates a new vector as a read-only link to OGR layer.

v.extract Selects vector objects from an existing vector map and creates a new map containing only the selected objects.

v.extrude Extrudes flat vector object to 3D with defined height.

v.generalize Vector based generalization.

v.hull Uses a GRASS vector points map to produce a convex hull vector map.

v.in.ascii Creates a vector map from ASCII points file or ASCII vector file.

v.in.db Creates new vector (points) map from database table containing coordinates.

v.in.dxf Converts files in DXF format to GRASS vector map format.

v.in.e00 Import E00 file into a vector map.

v.in.garmin Download waypoints, routes, and tracks from a Garmin GPS receiver into a vector map.

v.in.gns Imports US-NGA GEOnet Names Server (GNS) country files into a GRASS vector points map.

v.in.gpsbabel Import waypoints, routes, and tracks from a GPS receiver or GPS download file into a vector map.

v.in.mapgen Import Mapgen or Matlab vector maps into GRASS.

v.in.ogr Convert OGR vector layers to GRASS vector map.

v.in.region Create a new vector from the current region.

v.in.sites.all Converts all old GRASS < Ver5.7 sites maps in current mapset to vector maps.

v.in.sites Converts a GRASS site_lists file into a vector map.

v.in.wfs import GetFeature from WFS

v.info Outputs basic information about a user-specified vector map layer.

v.kcv Randomly partition points into test/train sets.

v.kernel Generates a raster density map from vector points data using a moving 2D isotropic Gaussian kernel or optionally generates a vector density map on vector network with a 1D kernel.

v.label Creates paint labels for a vector map from attached attributes.

v.lidar.correction Correction of the v.lidar.growing output. It is the last of the three algorithms for LIDAR filtering.

v.lidar.edgedetection Detects the object's edges from a LIDAR data set.

v.lidar.growing Building contour determination and Region Growing algorithm for determining the building inside

v.lrs.create Create Linear Reference System

v.lrs.label Create stationing from input lines, and linear reference system

v.lrs.segment Creates points/segments from input lines, linear reference system and positions read from stdin or a file.

v.lrs.where Finds line id and real km+offset for given points in vector map using linear reference system.

v.mkgrid Creates a GRASS vector map of a user-defined grid.

v.neighbors Makes each cell value a function of the attribute values assigned to the vector points or centroids around it, and stores new cell values in an output raster map layer.

v.net.alloc Allocate subnets for nearest centres (direction from centre).

v.net Network maintenance.

v.net.iso Split net by cost isolines

v.net.path Finds shortest path on vector network.

v.net.salesman Creates a cycle connecting given nodes (Traveling salesman problem).

v.net.steiner Create Steiner tree for the network and given terminals

v.net.visibility Visibility graph construction.

v.normal Tests for normality for points.

v.out.ascii Converts a GRASS binary vector map to a GRASS ASCII vector map.

v.out.dxf Exports GRASS vector map layers to DXF file format.

v.out.ogr Converts to one of the supported OGR vector formats.

v.out.pov Converts to POV-Ray format, GRASS x,y,z -> POV-Ray x,z,y

v.out.svg Exports a GRASS vector map to SVG.

v.out.vtk Converts a GRASS binary vector map to VTK ASCII output.

v.outlier Removes outliers from vector point data.

v.overlay Overlays two vector maps.

v.parallel Create parallel line to input lines

v.patch Create a new vector map layer by combining other vector map layers.

v.perturb Random location perturbations of GRASS vector points

v.proj Allows projection conversion of vector maps.

v.qcount Indices for quadrat counts of sites lists.

v.random Randomly generate a 2D/3D vector points map.

v.rast.stats Calculates univariate statistics from a GRASS raster map based on vector polygons and uploads statistics to new attribute columns.

v.reclass Changes vector category values for an existing vector map according to results of SQL queries or a value in attribute table column.

v.report Reports geometry statistics for vectors.

v.sample Samples a raster map at vector point locations.

v.segment Creates points/segments from input vector lines and positions.

v.select Select features from ainput by features from binput

v.split Split lines to shorter segments.

v.support Updates vector map metadata.

v.surf.bspline Bicubic or bilinear spline interpolation with Tykhonov regularization.

v.surf.idw Surface interpolation from vector point data by Inverse Distance Squared Weighting.

v.surf.rst Spatial approximation and topographic analysis from given point or isoline data in vector format to floating point raster format using regularized spline with tension.

v.to.db Populate database values from vector features.

v.to.points Create points along input lines in new vector with 2 layers.

v.to.rast Converts a binary GRASS vector map layer into a GRASS raster map layer.

v.to.rast3 Converts a binary GRASS vector map (only points) layer into a 3D GRASS raster map layer.

v.transform Performs an affine transformation (shift, scale and rotate, or GPCs) on vector map.

v.type Change the type of geometry elements.

v.univar Calculates univariate statistics for attribute. Variance and standard deviation is calculated only for points if specified.

v.univar.sh Calculates univariate statistics on selected table column for a GRASS vector map.

v.vol.rst Interpolates point data to a G3D grid volume using regularized spline with tension (RST) algorithm.

v.voronoi Creates a Voronoi diagram from an input vector map containing points or centroids.

v.what Queries a vector map layer at given locations.

v.what.rast Uploads raster values at positions of vector points to the table.

v.what.vect Uploads vector values at positions of vector points to the table.

v.buffer	Creates a buffer around features of given type (areas must contain centroid).
v.build.all	Rebuilds topology on all vector maps in the current mapset.
v.build	Creates topology for GRASS vector map.
v.build.polylines	Builds polylines from lines or boundaries.
v.category	Attach, delete or report vector categories to map geometry.
v.centroids	Adds missing centroids to closed boundaries.
v.clean	Toolset for cleaning topology of vector map.
v.convert.all	Convert all old GRASS < Ver5.7 vector maps in current mapset to current format
v.convert	Imports older versions of GRASS vector maps.
v.db.addcol	Adds one or more columns to the attribute table connected to a given vector map.
v.db.addtable	Creates and adds a new attribute table to a given layer of an existing vector map.
v.db.connect	Prints/sets DB connection for a vector map to attribute table.
v.db.dropcol	Drops a column from the attribute table connected to a given vector map.
v.db.droptable	Removes existing attribute table of a vector map.
v.db.join	Allows to join a table to a vector map table.
v.db.reconnect.all	Reconnects vectors to a new database.
v.db.renamecol	Renames a column in the attribute table connected to a given vector map.
v.db.select	Prints vector map attributes.
v.db.univar	Calculates univariate statistics on selected table column for a GRASS vector map.
v.db.update	Allows to update a column in the attribute table connected to a vector map.
v.delaunay	Creates a Delaunay triangulation from an input vector map containing points or centroids.
v.digit	Interactive editing and digitization of vector maps.
v.dissolve	Dissolves boundaries between adjacent areas sharing a common category number or attribute.
v.distance	Finds the nearest element in vector map 'to' for elements in vector map 'from'.
v.drape	Converts vector map to 3D by sampling of elevation raster map.
v.edit	Edits a vector map, allows adding, deleting and modifying selected vector features.
v.external	Creates a new vector as a read-only link to OGR layer.
v.extract	Selects vector objects from an existing vector map and creates a new map containing only the selected objects.
v.extrude	Extrudes flat vector object to 3D with defined height.
v.generalize	Vector based generalization.
v.hull	Uses a GRASS vector points map to produce a convex hull vector map.
v.in.ascii	Creates a vector map from ASCII points file or ASCII vector file.
v.in.db	Creates new vector (points) map from database table containing coordinates.
v.in.dxf	Converts files in DXF format to GRASS vector map format.
v.in.e00	Import E00 file into a vector map.
v.in.garmin	Download waypoints, routes, and tracks from a Garmin GPS receiver into a vector map.
v.in.gns	Imports US-NGA GEOnet Names Server (GNS) country files into a GRASS vector points map.
v.in.gpsbabel	Import waypoints, routes, and tracks from a GPS receiver or GPS download file into a vector map.
v.in.mapgen	Import Mapgen or Matlab vector maps into GRASS.
v.in.ogr	Convert OGR vector layers to GRASS vector map.
v.in.region	Create a new vector from the current region.
v.in.sites.all	Converts all old GRASS < Ver5.7 sites maps in current mapset to vector maps.
v.in.sites	Converts a GRASS site_lists file into a vector map.
v.in.wfs	import GetFeature from WFS
v.info	Outputs basic information about a user-specified vector map layer.
v.kcv	Randomly partition points into test/train sets.
v.kernel	Generates a raster density map from vector points data using a moving 2D isotropic Gaussian kernel or optionally generates a vector density map on vector network with a 1D kernel.
v.label	Creates paint labels for a vector map from attached attributes.
v.lidar.correction	Correction of the v.lidar.growing output. It is the last of the three algorithms for LIDAR filtering.
v.lidar.edgedetection	Detects the object's edges from a LIDAR data set.
v.lidar.growing	Building contour determination and Region Growing algorithm for determining the building inside
v.lrs.create	Create Linear Reference System
v.lrs.label	Create stationing from input lines, and linear reference system
v.lrs.segment	Creates points/segments from input lines, linear reference system and positions read from stdin or a file.
v.lrs.where	Finds line id and real km+offset for given points in vector map using linear reference system.
v.mkgrid	Creates a GRASS vector map of a user-defined grid.
v.neighbors	Makes each cell value a function of the attribute values assigned to the vector points or centroids around it, and stores new cell values in an output raster map layer.
v.net.alloc	Allocate subnets for nearest centres (direction from centre).
v.net	Network maintenance.
v.net.iso	Split net by cost isolines
v.net.path	Finds shortest path on vector network.
v.net.salesman	Creates a cycle connecting given nodes (Traveling salesman problem).
v.net.steiner	Create Steiner tree for the network and given terminals
v.net.visibility	Visibility graph construction.
v.normal	Tests for normality for points.
v.out.ascii	Converts a GRASS binary vector map to a GRASS ASCII vector map.
v.out.dxf	Exports GRASS vector map layers to DXF file format.
v.out.ogr	Converts to one of the supported OGR vector formats.
v.out.pov	Converts to POV-Ray format, GRASS x,y,z -> POV-Ray x,z,y
v.out.svg	Exports a GRASS vector map to SVG.
v.out.vtk	Converts a GRASS binary vector map to VTK ASCII output.
v.outlier	Removes outliers from vector point data.
v.overlay	Overlays two vector maps.
v.parallel	Create parallel line to input lines
v.patch	Create a new vector map layer by combining other vector map layers.
v.perturb	Random location perturbations of GRASS vector points
v.proj	Allows projection conversion of vector maps.
v.qcount	Indices for quadrat counts of sites lists.
v.random	Randomly generate a 2D/3D vector points map.
v.rast.stats	Calculates univariate statistics from a GRASS raster map based on vector polygons and uploads statistics to new attribute columns.
v.reclass	Changes vector category values for an existing vector map according to results of SQL queries or a value in attribute table column.
v.report	Reports geometry statistics for vectors.
v.sample	Samples a raster map at vector point locations.
v.segment	Creates points/segments from input vector lines and positions.
v.select	Select features from ainput by features from binput
v.split	Split lines to shorter segments.
v.support	Updates vector map metadata.
v.surf.bspline	Bicubic or bilinear spline interpolation with Tykhonov regularization.
v.surf.idw	Surface interpolation from vector point data by Inverse Distance Squared Weighting.
v.surf.rst	Spatial approximation and topographic analysis from given point or isoline data in vector format to floating point raster format using regularized spline with tension.
v.to.db	Populate database values from vector features.
v.to.points	Create points along input lines in new vector with 2 layers.
v.to.rast	Converts a binary GRASS vector map layer into a GRASS raster map layer.
v.to.rast3	Converts a binary GRASS vector map (only points) layer into a 3D GRASS raster map layer.
v.transform	Performs an affine transformation (shift, scale and rotate, or GPCs) on vector map.
v.type	Change the type of geometry elements.
v.univar	Calculates univariate statistics for attribute. Variance and standard deviation is calculated only for points if specified.
v.univar.sh	Calculates univariate statistics on selected table column for a GRASS vector map.
v.vol.rst	Interpolates point data to a G3D grid volume using regularized spline with tension (RST) algorithm.
v.voronoi	Creates a Voronoi diagram from an input vector map containing points or centroids.
v.what	Queries a vector map layer at given locations.
v.what.rast	Uploads raster values at positions of vector points to the table.
v.what.vect	Uploads vector values at positions of vector points to the table.