Autodesk 15606-011408-9330 User Guide - Page 178

centroid A point designated as the center of a polygon. A centroid is typically computed using information derived from the boundary of the polygon. Computed centroids generally lie within the polygon, but they can also lie outside of the polygon. CGI See Common Gateway Interface. character spacing ratio The ratio of the distance between text characters to average character width. For example, if the distance between text characters is 3.5 mm, and the character spacing ratio is 0.5, the average character width is 7 mm. Common Gateway Interface (CGI) An interface that allows server applications to work with Web servers. You can use the CGI version of the Autodesk MapGuide Server MapAgent to work with either Microsoft Internet Information Server or a Netscape Internet Server. complex symbols A symbol composed of one or multiple bitmaps and one or multiple vector graphics, all of which appear as one symbol in the associated layer. Computer Aided Acquisition and Logistics Support (CALS) A format for compressing raster images. MapGuide supports CALS MIL-R_28002A Type 1 Format. This format typically works best for black-and-white images that use 1 bit per pixel. coordinate system Any of a number of reference systems used to define the unique location of a point in space and to reference point, line, and area information by defining its geographic location. A coordinate system is usually defined by a projection, an ellipsoid definition, a datum definition, one or more standard parallels, and a central meridian. coordinate system origin The reference location for a planar coordinate system that is stored with a map. Coverage A data format that includes files created in ESRI Arc/Info. You can convert these files to latitude/longitude SDFs using the SDF Loader. CTRL-click A method of selecting multiple, non-contiguous items in a list by holding down the CTRL key, and then clicking each item you want to select. database A collection of interrelated alphanumeric data files controlled by a database management system (DBMS). Databases are structured so that the DBMS can perform rapid search and retrieval by various data elements. In Autodesk MapGuide, "database" refers to a relational database that stores attribute data, such as a database of records that contain information like population and area for each country. See also RDBMS. data provider A data provider that can process spatial queries and access spatial data. You can purchase Autodesk MapGuide data providers for Autodesk GIS Design Server, Oracle Spatial, and ArcView SHP. data source A Microsoft Data Link (UDL) file or Autodesk Data Link (ADL) file, with a .udl or .adl extension. These files contain all the information required to connect to a specific data provider. Before you can access an external database from within Autodesk MapGuide, you must configure it as an OLE DB or Autodesk DWG data source. Data Source Name (DSN) An ODBC data source that contains information about how to connect to a particular database, spreadsheet, or other data source. You can set up User DSNs, which are available only when you log on to your computer, and System DSNs, which are available to all users and to NT services on your computer. 178 | Glossary