Requirements

Functional

Function: Compare two spatial data sets.
Description: Computes a delta between two spatial data sets.
Input: Two versions of the same spatial data set at different instants.
Source: Imported by the user.
Output: A visualization of the delta.
Destination: The screen.
Action: The two sets are compared and a delta is produced. This delta is then shown to the user, highlighting the additions, deletions and modifications.
Requirement: Two geographical data sets.
Pre-condition: They represent the same data (at two different instants).
Post-condition: The delta represents all differences.
Side-effects: None.