Navigating Contextual Complexity with Graph Visualization
Figure
4-14 : Automatically generated graph layout of an example HVAC system .
As stated in section 4.1 , the type of visualization and navigation required to work with instance graphs that represent real systems is typically very different from what is required to model them . End users in these systems require only as much context as is needed to explain or explore the instance in a manner suited to the user ’ s task . Often , the task is to understand the run-time conditions of the systems in a specific facility . In the case of our example , the instance graph of the system can be described by the simple schema in Figure 4-15 . The details , such as the type and connection information supplied by the IFC meta-model have become attributes on the nodes and edges in the instance graph .
The schema that underlies the visualization in Figure 4-14 is shown in Figure 4-15 .
Figure 4-15 : Simple schema for a directed system graph .
Domain-aware visualization of the schema relies on the domain details provided to populate information about each device . This simple model of devices connected by directed edges is a
Journal of Innovation 89