This macro draws an object called a Henon Strange Attractor. The equations used
have their origins in studies of self-organizing systems and chaos theory. For
more information on this subject I suggest you perform web searches on these
topics:
Henon attractor
Hamiltonian chaos
Hamiltonian mapping
KAM torus
KAM tori
The equations used in this macro are credited to Edward Rietman. Despite
all this fancy science, the macro is very simple, as you can see. When started,
an input box will ask you to supply the value of "A" to be used in
plotting the attractor system. The rest of the values used are set in the
code. The macro then places dots in the drawing in 2D coordinates
to map the system. Basically, the system will appear "stable"
for many values of "A", but will break up at certain values. Around
the values that cause instability, very small changes in "A" will
cause marked changes in the attractor. Try these values of A: 1.1; 1.2;
1.264; 1.265; 1.275, 1.3, 1.35; 1.5; 1.57; 1.575; 1.58; 1.591; 1.6; 1.601;
1.602; 1.7 To completely clear an attractor in the drawing before
drawing a new one, I suggest you use the menu commands Edit|Select|All