Note: A new GRASS GIS stable version has been released: GRASS GIS 7, available here. And see the new manual page here

**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).

Go to vector introduction
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**vector commands:**

v.buffer | Creates a buffer around vector features of given type. |

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.class | Classifies attribute data, e.g. for thematic mapping |

v.clean | Toolset for cleaning topology of vector map. |

v.colors | Set color rules for features in a vector using a numeric attribute column. |

v.convert.all | Converts all older versions of GRASS 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 connects 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 | Joins a database 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 | Updates 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 | Produces a convex hull for a given 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.info | Outputs basic information about a user-specified vector map. |

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

v.in.geonames | Imports geonames.org country files into a GRASS vector points 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.lines | Import ASCII x,y[,z] coordinates as a series of lines. |

v.in.mapgen | Imports Mapgen or Matlab-ASCII vector maps into GRASS. |

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

v.in.region | Creates a vector polygon from the current region extent. |

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

v.kernel | Generates a raster density map from vector point data using a moving kernel or optionally generates a vector density map on a vector network. |

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

v.label.sa | Create optimally placed labels for vector map(s) |

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 | Creates Linear Reference System |

v.lrs.label | Creates 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.allpairs | Computes the shortest path between all pairs of nodes in the network. |

v.net.bridge | Computes bridges and articulation points in the network. |

v.net.centrality | Computes degree, centrality, betweeness, closeness and eigenvector centrality measures in the network. |

v.net.components | Computes strongly and weakly connected components in the network. |

v.net.connectivity | Computes vertex connectivity between two sets of nodes in the network. |

v.net.distance | Computes shortest distance via the network between the given sets of features. |

v.net.flow | Computes the maximum flow between two sets of nodes in the network. |

v.net | Performs network maintenance. |

v.net.iso | Splits 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.spanningtree | Computes minimum spanning tree for the network. |

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

v.net.timetable | Finds shortest path using timetables. |

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.gpsbabel | Exports a vector map to a GPS receiver or file format supported by GpsBabel. |

v.outlier | Removes outliers from vector point data. |

v.out.ogr | Converts GRASS vector map 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.overlay | Overlays two vector maps. |

v.parallel | Creates parallel line to input vector 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 | Re-projects a vector map from one location to the current location. |

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 raster map based on a vector map 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 | Selects features from vector map (A) by features from other vector map (B). |

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.3d | Performs transformation of 2D vector features to 3D. |

v.to.db | Populates database values from vector features. |

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

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

v.to.rast | Converts (rasterize) a vector map into a raster map. |

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.vect.stats | Count points in areas, calculate statistics. |

v.vol.rst | Interpolates point data to a 3D raster map 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. |

Help Index | Full Index

© 2003-2016 GRASS Development Team, GRASS GIS 6.4.6svn Reference Manual