Vector data
Vector data is data with a one-dimensional domain units, with at least one feature attribute and one or more other attributes for the same domain unit.
A feature attribute can contain one (point data) or a sequence of elements (arc / polygon data) per entry.
The GeoDMS supports:
- point: point data, the feature attribute contains one coordinate per entry.
- arc: arc data, the feature attribute contains at least two coordinates per entry.
- polygon: polygon data, the feature attribute contains at least three coordinates per entry.
It is important to know the coordinate system of your vector data, as they may effect the results of functions like arc_length and connect_info.
Vector data in GeoDMS applications is read from the following formats:
- ESRI_Shapefile (point, arc, polygon)
- PostgreSQL PostGIS (point, arc, polygon, ODBC(point) or FileGeoDatabase (point, arc, polygon) or GeoPackage (point, arc, polygon)
- ASCII Files : CSV (point) and XML (point, arc, polygon)
Shapefiles, CSV Files, PostgreSQL_PostGIS and GeoPackage databases can be read with the gdal.vect StorageManager. This StorageManager also supports also reading other formats, but they are not tested (yet).
The gdal.vect StorageManager always names the feature attribute geometry.
The gdal.vect StorageManager automatically segments large arrays in segments of maximum 50.000 entries.
The GeoDMS also contains other StorageManagers to:
- Read data from and write to ESRI Shapefiles (point, arc, polygon)
- Write data to csv Files (point)
- Read data from XML files (point, arc, polygon)
- Read data from and write to FSS files (point, arc, polygon)
