< Day Day Up > |
These are also known as DGN files. Data is encapsulated in a single file, usually with the suffix .dgn; for example: 0824t.dgn. Data access/connection method
ogrinfo examplesUsing ogrinfo on a single DGN fileNote that no geometry/feature type for the layer is identified because it can be multiple types. > ogrinfo /data/dgn/0824t.dgn Had to open data source read-only. INFO: Open of '0842t.dgn' using driver 'DGN' successful. 1: elements Using ogrinfo to examine the structure of the file/layerDGN files aren't really GIS data files. They evolved from drafting formats used by computer-aided drafting/design (CADD) programs. They carry a few key attributes that are usually consistent across all DGN files. Most of the attributes relate to graphical styling of features for map presentation, such as ColorIndex, Style, etc. Spatial reference system information isn't always encoded into DGN files. This can be a major problem when trying to adequately reference the DGN data in another mapping program. Measurement units can be a problem. In some cases the features could be located in kilometers or feet even though it isn't obvious from the output of ogrinfo. Sometimes the only way to identify or correct a problem with units is to open the file in Microstation software. > ogrinfo -summary /data/dgn/0824t.dgn elements INFO: Open of '0824t.dgn' using driver 'DGN' successful. Layer name: elements Geometry: Unknown (any) Feature Count: 22685 Extent: (-513183.050000, 150292.930000) - (-224583.220000, 407463.360000) Layer SRS WKT: (unknown) Type: Integer (2.0) Level: Integer (2.0) GraphicGroup: Integer (4.0) ColorIndex: Integer (3.0) Weight: Integer (2.0) Style: Integer (1.0) EntityNum: Integer (8.0) MSLink: Integer (10.0) Text: String (0.0) Map file exampleLAYER NAME dgn TYPE LINE STATUS DEFAULT CONNECTIONTYPE OGR CONNECTION "dgn/0824t.dgn,0" STYLEITEM "AUTO" CLASS END END # Layer |
< Day Day Up > |