Sysquake LE On The Web
Sysquake LE
is a free version of Sysquake.
Sysquake brings life to boring static figures. With it, you can not only
display graphics, but interact with them thanks to your mouse. You will
immediately understand the effect of parameters, how to make a system
perform better, or what an obscure mathematical theorem is about. Sysquake
LE is much safer than Sysquake when it is used with files downloaded
from the World Wide Web, because it does not support programlevel
stealth access to files on your hard disk.
Sysquake LE replaces Sysquake Viewer.
Installation
Once you've installed Sysquake LE, you'll be a single click away from
the live graphics listed below!
To install Sysquake LE on your own computer (Mac or PC), please
follow these simple instructions (the current
version is 1.3 for Macintosh and Windows (12 Sept. 00) and Sysquake Viewer
1.2 PR5 for Linux Intel and PowerPC (3 Feb. 00); please download it if
you've got a previous version). Then come back and try the SQ files below!
We will add new files in the next weeks and months; come back often!


Mathematics
SQ File  Date  Description  Ref. 
triangle.sq 
04.10.99 
Triangle, medians, perpendicular bisectors and bisectors, and circumscribed and inscribed
circles (you can drag the corners of the triangle). 

bezier3.sq 
29.11.99 
Bezier curve of order 3 (you can drag the control points, displayed as red circles). 

moebius.sq 
28.12.99 
Möbius transformation (you can drag the two fixed points, displayed as red
circles, and one point of the figure; hold down the Shift key to constrain the
transformation to an elliptic or hyperbolic transformation instead of the more
general loxodromic transformation). 
[6] 
convExp.sq 
31.07.99 
Convolution of two exponential functions (you can shift one of the operands and
see how the integral is defined). 
[4] 
cor.sq 
12.08.99 
Correlation to find the position of a square in a noisy signal (you can shift
the square and see how the correlation integral is defined). 
taylor.sq 
31.07.99 
Taylor approximation of a sine (you can change the polynomial order and the point
where the derivatives are evaluated). 
cheb.sq 
06.08.99 
Chebyshev approximation of a sine (you can change the polynomial order and the region
where the error is made as small as possible). 
[7] 
gibbs.sq 
22.11.99 
Gibbs effect; the Fourier serie of a sawtooth signal does not converge to
the approximated signal (you can change the number of terms of the approximation). 
lissajou.sq 
25.08.99 
Lissajou figure (you can change the phase between x and y). 
triang.sq 
04.10.99 
Triangulation (you can move the points). 
voronoi.sq 
26.10.99 
Voronoi diagram (you can move the points). 
cvoronoi.sq 
26.10.99 
Color Voronoi diagram and triangulation; each Voronoi region is colored in
one of four colors, taking advantage of the fourcolor theorem (you can move the
points). 
Physics
SQ File  Date  Description 
potlines.sq 
05.08.99 
Potential lines in a electrostatic field created by three charges
(you can drag the charges). 
pendulum.sq 
23.11.99 
Simulation of a pendulum, in the phase plane and as a function of time
(you can change the initial angle and velocity, represented by a red circle in
the phase plane). 
Demography
SQ File  Date  Description 
dem_evol.sq 
05.08.99 
Evolution of the Swiss population
(you can simulate the evolution of the pyramid by dragging it up, or dragging the green
line in the population evolution graphic). 
dem_ret.sq 
05.08.99 
Evolution of the ratio between active and retired people (you can change the
age limits of the groups by dragging the green lines in the pyramid). 
Automatic Control
SQ File  Date  Description  Ref. 
step2ndo.sq 
27.10.00 
Continuoustime step response of a 2ndorder transfer function (you can shape
the step response and drag the poles). 
[4] 
zpstep.sq 
03.07.00 
Continuoustime step response of a 3rdorder transfer function with a zero
(you can drag the poles and the zero, and observe the effect of a nonminimumphase
zero: the step response has an undershoot when you move the zero to the right of
the imaginary axis). 
[4] 
rloc_dt.sq 
04.08.99 
Synthesis of a PD controller in the rlocus (you can drag the openloop zero
of the controller (red circle) and the closedloop poles (triangles) along the
root locus (black line)). 
[1] 
PI_sat.sq 
04.08.99 
PIcontrolled system with input saturation (you can change the saturation
(red line) and the frequency of the setpoint (blue signal)). 
[2] 
PI_s_ARW.sq 
04.08.99 
PIcontrolled system with input saturation and AntiReset Windup (you can
change the saturation (red line) and the frequency of the setpoint (blue
signal)). 
[2] 
pp_dt.sq 
04.08.99 
Pole placement design of a discretetime RST controller (you can drag the
closedloop poles and observe the step response, Nyquist diagram and sensitivity). 
[2] 
relay2.sq 
11.08.99 
Relay controller for a secondordem continuoustime system (you can drag the
hysteresis and observe the time response and the phase plane). 
[5] 
relay3.sq 
11.08.99 
Relay controller for a thirdorder continuoustime system (you can drag the
hysteresis and observe the time response and the phase plane). 
[5] 
GPC_c.sq 
18.08.99 
GPC (Generalized Predictive Control) (you can drag the
prediction (blue) and control (red) horizons). 
[3] 
Signal Processing
SQ File  Date  Description  Ref. 
minphase.sq 
07.08.99 
Comparison between minimumphase (MP) and nonminimumphase (NMP) systems (you can drag
the poles and zeros of a continuoustime transfer function and compare the
frequency and step responses of the MP and NMP systems). 
[4] 
samplZOH.sq 
05.08.99 
Conversion of a continuoustime model (black) to a discretetime model (red)
using a sampler and a zeroorder hold (you can drag the Nyquist frequency (green),
the sample frequency (blue) or one of the samples (red circle)). 
[2] 
cmp_c2d.sq 
19.08.99 
Comparison of different methods (zeroorder hold, bilinear, backward
difference, and forward difference) for converting a system from continuous time
to discrete time (you can drag the Nyquist frequency (vertical line), and the
continuoustime poles). 
butterw.sq 
23.09.99 
Digital lowpass Butterworth filter, with the frequency response magnitude and the
poles in the complex plane (you can drag the cutoff frequency (vertical line)). 
[8] 
chebfltr.sq 
09.11.99 
Digital highpass Chebyshev filter, with the frequency response magnitude and the
poles in the complex plane (you can drag the cutoff frequency (vertical line) and the
ripple lower limit (horizontal line)). 
[8] 
Miscellaneous Demonstrations
SQ File  Date  Description 
salesman.sq 
04.08.99 
Shortest path of a salesman (you can drag around the towns and the river). 
cells.sq 
23.09.99 
Cellular automata; at each step of the animation, cells are born, survive,
or die depending on the number of neighbors (no interactivity). 
clock.sq 
23.08.99 
Clock with date to permit you to check whether the date given to Sysquake by
the operating system is Y2Kcompliant (no interactivity, but you can still zoom in and out). 
References
[1] 
J. Ackermann, SampledData Control Systems, SpringerVerlag, Berlin, 1985. 
[2] 
K.J. Åström and B. Wittenmark, ComputerControlled Systems, Theory and
Design, 2nd ed., Prentice Hall International, Englewood Cliffs, NJ, 1990. 
[3] 
D.W. Clarke and C. Mohtadi, 1989, "Properties of Generalized
Predictive Control", Automatica vol. 25 no 6 pp. 859875. 
[4] 
R.C. Dorf and R.H. Bishop, Modern Control Systems, 8th ed. Addison Wesley Longman,
Menlo Park, CA, 1998. 
[5] 
A. Gelb and W.E. Vander Velde, MultipleInput Describing Functions and
NonLinear System Design, McGrawHill, New York, 1968. 
[6] 
M. Henle, Modern Geometries, the Analytic Approach,
Prentice Hall, Upper Saddle River, NJ, 1997. 
[7] 
J.H. Mathews, Numerical Methods for Mathematics, Science, and Engineering, 2nd ed.,
Prentice Hall International, Englewood Cliffs, NJ, 1992. 
[8] 
T.W. Parks and C.S. Burrus, Digital Filter Design, John Wiley & Sons, New York, 1987. 
Copyright
Unless specified otherwise, all SQ files on this page have been written and are
copyrighted by Yves Piguet. They may be downloaded from this page and used with Sysquake
and Sysquake LE. They may not be redistributed (e.g. from another server or via a
physical medium such as a cdrom) without the written authorization of their author.
However, fragments may be freely reused in SQ files for Sysquake or Sysquake LE.
