For tool vendors, the
notation side de?¬?nitely seems to be a harder task. Even the most basic part, the
facilities for de?¬?ning the graphical symbols, has proved troublesome to nearly all tool
builders.
Representational Paradigms The clear majority ofDSMlanguages have been
graphical diagrams: nodes and edges, boxes and lines, bubbles and arcs. The same
modeling language, or more exactly its abstract syntax, can however be represented in
a number of different representational paradigms: as a matrix, table, or structured text.
A matrix representation shows the objects on the axes of the matrix, like row and
column labels in a spreadsheet, and a relationship between a pair of objects is shown
in the appropriate cell. The matrix is thus useful for focusing on relationships,
particularly where there are binary relationships each connecting an object of one
type to an object of another type. An example of this was seen in Figs. 9.5 and 9.6
for the Watch family diagram. In the former, each WatchModel object had properties
referring to the Display object and LogicalWatch object from which it was
composed. In the latter, these structure were turned intoWatchModel relationships
that directly connected Displays and LogicalWatches. Figure 14.1 shows a diagram
and a matrix displaying the relationship approach, and a table displaying the
property approach.
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