Data item

The GeoDMS calculates and visualises data. Therefore tree items can to be configured, referring to source data or calculation results. These items are called data items.

From a technical perspective a data item is a reference to a memory array.

StorageManagers are used to read data from files and databases into memory arrays and to write data from these arrays to files.

Small amounts of data, like parameter values or class breaks of Classifications, are often stored in configuration files.

Configure expressions to calculate with data items.


Two types of data items are distinguished:

  1. parameter
  2. attribute


Most data items are one-dimensional. The GeoDMS also supports the following multi-dimensional (spatial) datastructures:

  1. point data items: two-dimensional items with for each instance an X and an Y value.
  2. sequence of point data item: items with for each instance a non fixed number of coordinates, used for arc and polygon data items.

Different value types and composition types are used to configure multi-dimensional data structures, see units.