WHAT IS NEEDED IN A DSM ENVIRONMENT 373
FIGURE 14.1 Diagram, Matrix, and Table representations
374 TOOLS FOR DSM
As should be clear from the picture, sometimes the table and matrix representations
have signi?¬?cant advantages in terms of compactness and scalability. Mapping
between four Displays and four LogicalWatches works reasonably in a diagram: in
this case the lines do not even cross each other. Somewhere between four and eight this
kind of diagram would probably break down, if the WatchModel connections were
random. The earlier diagram, Fig. 9.5, would scale slightly better, but is perhaps less
clear visually.Amatrix would cope with up to 15??“20 of each kind of object, and many
more WatchModel relationships, while providing a good view of both objects and
relationships. A table would scale to over 50 WatchModels, but offers less help in
visualizing which Displays and LogicalWatches are used where.
Graphical Symbol Editor Given that the direct manipulation vector graphic
editor has been around since 1961 (Sutherland, 1963)??”8 years before ARPANETand
IBM??™s ?¬?rst 1 KB RAM chip??”it is hardly impressive to say that of all the tools, to our
knowledge only two have provided metamodelers with a graphical symbol editor:
MetaEdit and MetaEdit+. This must surely change in the near future, but the failure of
earlier tools leads us to suspect that it may take a little time before the other current
tools get it right.
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