The main goal of Sysquake is the interactive manipulation of
play an important role in SQ files.
There are low-level commands for basic shapes as well as high-level
commands for more specialized plots:
Low-level commands add simple shapes such as lines, marks,
polygons, circles and images. With them, you can display virtually
everything you want. Arguments of these commands are such that it
is very easy to work globally with matrices without computing each
value sequentially in a loop.
High-level commands perform some computation of their own
to process their arguments before displaying the result. This has
two benefits: first, the code is simpler, more compact, and faster
to develop. Second, command execution is faster, because the
additional processing is not interpreted by LME, but implemented
as native machine code. The information related to interactive
manipulation is often easier to use, too. Most of these functions
are related to automatic control and signal processing.
Commands which display data in a figure can be used only in the draw
handlers or from the command line interface. Conversely, commands which
change the number of subplots or the subplots themselves cannot be used in the
Here is the list of these two groups of commands:
Reserved for draw handlers and command-line interface
Commands from both groups can be typed in the command line interface.
For example, to plot the step
response of the continuous-time system whose Laplace transform
is 1/(s^3 + 2 s^2 + 3 s + 4), type
> step(1, [1,2,3,4])
The first command, only valid from the command line interface (or indirectly
in a function called from the command line interface), clears
the figure window (necessary if there was
already something displayed); the second command integrates the system
over a suitable range with a unit entry and null initial conditions.