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Sysquake Pro – Table of Contents

Sysquake – Table of Contents

Sysquake for LaTeX – Table of Contents

# Graphics

The main goal of Sysquake is the interactive manipulation of graphics. Hence, graphical functions 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
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
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 draw handlers.

Here is the list of these two groups of commands:

Reserved for draw handlers and command-line interface

2D low-level drawing commands

2D high-level drawing commands

Note that some of these functions can be used in non-draw handlers when the result is retrieved in output arguments and not displayed.

Scaling and labels

3D

3D scaling and lighting

Controls

Cannot be used in draw handlers

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

```> clf
> 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.