Shape and GeoJSON files as an interface to GIS

Shape and GeoJSON files are data formats for geodata that are used in most GIS. The data formats are especially suitable for the data exchange between Visum and GIS. With Visum you can both open and save shape and GeoJSON files (Using Visum: The Shapefiles interface).

Note: To save shape and GeoJSON files, you need the add-on GIS interface shape.

A shape file is not an individual file, but is made up of three files:

• File *.shp for saving geometry data
• File *.shx contains the geometry index to link to the attribute data
• File *.dbf contains attribute data in dBase data format. You can assign the attributes contained here a Visum attribute, when reading the shape file (Using Visum: Reading an attribute file).

Shape files can contain points, lines or polygons (surfaces). Only one type of element can be contained in a shape file.

Note: A technical description of the data format can be found on the Internet at www.esri.com/library/whitepapers/pdfs/shapefile.pdf.

GeoJSON is a modern format that is used by many open data portals and web services. Unlike shape files, GeoJSON files can contain elements of several geometry types. A technical description of the format can be found on the Internet at https://datatracker.ietf.org/doc/html/rfc7946. PTV Visum supports the import of GeoJSON files that comply with this specification, i.e. in particular that use the WGS-84 coordinate system as the reference coordinate system.

The following sections cover the import and export of shape and GeoJSON files. The functionality is structured in the same way. Special features and differences are explicitly addressed.