User`s guide

Foreword
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What Is Simulink?
Simulink is a software package for modeling, simulating, and analyzing
dynamic systems. It supports linear and nonlinear systems, modeled in
continuous time, sampled time, or a hybrid of the two. Systems can also be
multirate, i.e., have different parts that are sampled or updated at different
rates.
For modeling, Simulink provides a graphical user interface (GUI) for building
models as block diagrams, using click-and-drag mouse operations. With this
interface, you can draw the models just as you would with pencil and paper (or
as most textbooks depict them). This is a far cry from previous simulation
packages that require you to formulate differential equations and difference
equations in a language or program. Simulink includes a comprehensive block
library of sinks, sources, linear and nonlinear components, and connectors. You
can also customize and create your own blocks.
Models are hierarchical, so you can build models using both top-down and
bottom-up approaches. You can view the system at a high-level, then
double-click on blocks to go down through the levels to see increasing levels of
model detail. This approach provides insight into how a model is organized and
how its parts interact.
After you define a model, you can simulate it, using a choice of integration
methods, either from the Simulink menus or by entering commands in
MATLAB’s command window. The menus are particularly convenient for
interactive work, while the command-line approach is very useful for running
a batch of simulations (for example, if you are doing Monte Carlo simulations
or want to sweep a parameter across a range of values). Using scopes and other
display blocks, you can see the simulation results while the simulation is
running. In addition, you can change parameters and immediately see what
happens, for “what if” exploration. The simulation results can be put in the
MATLAB workspace for postprocessing and visualization.
Model analysis tools include linearization and trimming tools, which can be
accessed from the MATLAB command line, plus the many tools in MATLAB
and its application toolboxes. And because MATLAB and Simulink are
integrated, you can simulate, analyze, and revise your models in either
environment at any point.
Stateflow is part of this environment. The Stateflow block is a masked
Simulink model. Stateflow builds an S-function that corresponds to each