The original Duration Calculus was introduced by Zhou Chaochen et al. . Several ex- tensions have been proposed, notably the Mean Value Calculus , that extends Duration Calculus to deal with point intervals. In this work we consider the Mean Value Calculus with continuous semantics.
We defined a set of rules to relate the semantics of data, hardware and task with the configuration of the visualization technique. Based on the semantics defined earlier we created the rules shown in Fig. 2; in these rules we considered that the user may or may not want to perform the task filter. This is represented by the condition isTask, that when true means to filter certain elements and otherwise means to do nothing. The function that appears in the set of rules determinates if it is possible to fit the tree in the visualization viewport. The result from the reasoning process in this stage is a concept called Configuration indicating which visual elements to use in the visualization. This set of rules allow us to control how the visualization is created to make the most out of the current hardware.
A well-formed model is a correctly constructed model. UML specification does not formally define this concept. Constructs are defined by means of UML notation, natural language and well- formedness rules. In we have classified semantic information, according to its genericity, as Rules and Constraints. We can define now a well-formed model as one that satisfies all the predefined and model-specified rules and constraints. Such a model has meaningful semantics. A model that is not well formed is called ill-formed . A metamodel describes the contents of a well- formed model; it does not make sense to ask for the semantics of an ill-formed model.