TANGRAM-II allows to be performed. Then all state variables described in the model are updated during the evolution of the simulation. This kind of simulation is useful for debugging the model, and for educational purposes.
Animation is another feature available to the user. In this case, the object has pre-defined animations that are executed according to the states the object reaches.
The animation is specified by the user, by introducing a new attribute to an
object: the Animation attribute. Using this attribute, the user should
specify the animation of the object and others related objects. Note that the
object being used in the model specification should not be used
for simulation with animation. A separate TGIF object should perform the
animation. The procedures, of calling an animated object and of specifying an
animation, has to be done using TGIFs internal commands, that are similar to a
programming language. TGIF supports a few animation primitives that can be used
to perform the animations. A good reference of all supported commands can be
found in the TGIF manual (http://bourbon.cs.umd.edu:8001/tgif). After a
simulation step, the animation starts and a pre-defined number of animation
steps are executed before resuming the simulation. ``Simultaneous'' animation
of different objects are allowed and each animation is performed only at
specified steps. The Interactive Simulation Module is shown in Figure
.
We have three types of interactive simulations. The first, called step simulation, allows the user to specify the number of steps to be executed before the simulation is interrupted. In the second type, continuous simulation, the simulation is stopped at each transition of the model. Finally, the third type is simulation with . Each time the simulation stops, the user can observe on the canvas the current values of the model's state variables.
The following parameters must be given to an interactive simulation :
The simulation behavior depends on the type previously chosen. If the user
choose , the values of the state variables are
displayed at each step. To proceed to the next step, the user has to click on
the step button (see Figure ). To end the
simulation, the user has to click on the end button which closes the
interface, and then on the close button.
If the option chosen by the user, was continuous simulation, he/she should click
on the step button. Then, after each transition of the model, the
values of the states variables are displayed at intervals equal to the given
time between steps. To stop the simulation, the user must click on the progress
indicator of the TGIF interface (see Figure ). After
stopping, she can resume the simulation by clicking on the step button
or she can finish the simulation by clicking on the end button.
If the option chosen by the user, was , he/she
should click on the step button. Then, after each transition of the
model, the values of the states variables are displayed at intervals equal to
the given time between steps. To stop the simulation, the user must click on
the progress indicator of the interface (see Figure
). After stopping, she can resume the simulation by
clicking on the step button, or she can finish the simulation by
clicking on the end button.
In the animation option, the procedure to be employed by the user is the same as for continuous simulation.
Guilherme Dutra Gonzaga Jaime 2010-10-27