Strophoid (simple)

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Star (fractal) TriCircles (simple)

Strophoid (simple)

Example:    Strophoid.eli
Modified:   May 31, 2000
Version:    2.0
Author:     Peter Moxhay
E-mail:     moxhay@bestpraceduc.org

Copyright © 2000 Elica Group

Example for drawing an strophoid curve; its parametric representation is:
	x = a(t^2-1)/(t^2+1)
	y = at(t^2-1)/(t^2+1)
The curve has an asymptote at x=a.

run "Geomland

Oxy
make "a 100
make "tn 5
make "dt 0.1
make "N trunc 2*:tn/:dt
make "t (-:tn)

repeat :N
[
	make "t2 :t*:t
	make "D (:t2-1) / (:t2+1)
	make "X :a*:D
	make "Y :a*:t*:D
	make "P point :X :Y [traced historical]
	make "t :t+:dt
]

make "L line first :history.P last :history.P

Star (fractal) TriCircles (simple)