Environmental Engineering Reference
In-Depth Information
and testing them against the state of the system. If a rule is satisfied, the coupled
impact (a class implementing the interface IManagement) is published. The ACG
uses rules and impacts to build sets of rule-impact couples. ACG allows also files to
be merged and uses the component CRA.AgroManagement.AFD to display
planned agro-management actions using a graphical metaphor (see Fig.
4.3
).
The Model Parameter Editor
Developing and maintaining a simulation system implies, among other things, that
the parameters used can change. Composite models are made of simpler models,
which can be often replaced by alternative formulations. This means that the
development and management of a simulation system requires the ability to deal
with changing the number and type of the parameters of the composite model when
a sub-model is substituted. If the system consists of interchangeable components,
the need for dealing with different sets of parameters is an inherent feature of the
system; an alternative component may model the same domain variables, but its
approaches may demand different, model-specific, parameters.
The need for changing parameters has a primary impact on the Graphical User
Interfaces developed for the system: such user interfaces must be easily maintainable,
and ideally present the same look and feel to the user when different sets of para-
meters are in use. Moreover, there should be a facility to check the accuracy of all
parameter values. A parameter editor with these features must allow the parameters
to be edited to be changed without changing the code, hence without a need for
re-compilation of the editor.
The Model Parameter Editor (MPE) is an application developed by CRA
(Di Guardo et al.,
2007
) which allows a dedicated user interface to be generated
for each available parameter definition. It groups interfaces in different tabs either
according to user criteria, or according to the model components which originate the
parameter definitions. The application allows selection of parameter definitions, or
it loads automatically parameter definitions from a folder of choice. MPE can be
used as a stand-alone application, but it is meant to be used primarily in a simula-
tion system like APES, becoming one object of the Graphical User Interface.
The Graphic Data Display Component
Providing data views from Graphical User Interfaces is a common need for applications
built to make use of models. If model output is generated by a modular system
in which model components are interchangeable, output variables may change.
Thus, maintaining GUIs can be challenging and resource demanding. A tool which
can load datasets with various schemas and which helps the user to visualize data
in a range of ways speeds up application development, allowing the user to focus
