/*! \mainpage GRASS 6.0 Vector Architecture by GRASS Development Team http://grass.itc.it \section intro Introduction This describtion covers the new GRASS 5.7/6.0 vector library architecture. This new architecture overcomes the vector limitations of GRASS 4.x-5.4.x by extending the vector support with attributes stored in external relational databases and by new 3D capabilities. Besides internal file based storage the geometry may alternatively be stored in PostGIS database. This enables users to maintain large data sets with simultaneous write access. External GIS formats such as SHAPE-files may be used directly without necessity of format conversion. \section background Background In GIS the vector data model is used for geographic phenomena which may be represented by geometric entities (primitives) like points, lines, and areas. The GRASS vector data model includes the description of topology, where besides the coordinates describing the location of the points, lines, boundaries and centroids also their spatial relations are stored. In general, topological GIS require a data structure where common boundary between two adjacent areas is stored as a single line, simplifying the map maintenance. \section libraries Libraries Besides internal library functions there are two main libraries: \subsection vlib Vlib (Vector library) For details please read Blazek et al. 2002 (see below) as well as the references in this document. The Vect_*() functions are the programmer's API for GRASS vector programming. See details here: Structured Vect_*() functions list \subsection dglib DGLib (Directed Graph Library) The Directed Graph Library or DGLib (Micarelli 2002, http://grass.itc.it/dglib/) provides functionality for vector network analysis. This library released under GPL is hosted by the GRASS project (in the CVS server within the GRASS source code). As stand-alone library it may also be used by other software project. The Directed Graph Library library provides functionality to assign costs to lines and/or nodes. That means that costs can be accumulated while traveling along polylines. The user can assign individual costs to all lines and/or nodes of a vector map and later calculate shortest path connections based on the accumulated costs. Applications are transport analysis, connectivity and more. For details please read Blazek et al. 2002 (see below). \section contacts Contacts Radim Blazek (vector architecture) Roberto Micarelli (DGLib) \section references References Text based on: R. Blazek, M. Neteler, and R. Micarelli. The new GRASS 5.1 vector architecture. In Open source GIS - GRASS users conference 2002, Trento, Italy, 11-13 September 2002. University of Trento, Italy, 2002. http://www.ing.unitn.it/~grass/proceedings/proceedings/pdfs/Blazek_Radim.pdf \section seealso See Also DBMI - Database Management Interface Last change: $Date$ */