Peter de Jong Attractors

Written by Paul Bourke
January 1991, Updated February 2004

See "The Pattern Book, Fractals, Art, and Nature"
by Clifford Pickover, chapter titled "Swirl".

xn+1 = sin(a yn) - cos(b xn)
yn+1 = sin(c xn) - cos(d yn)



a = 1.4, b = -2.3, c = 2.4, d = -2.1




a = 2.01, b = -2.53, c = 1.61, d = -0.33




a = -2.7, b = -0.09, c = -0.86, d = -2.2




a = -2.24, b = 0.43, c = -0.65, d = -2.43




a = -2, b = -2, c = -1.2, d = 2


Contribution by Johnny Svensson

A variation:

xn+1 = d sin(a xn) - sin(b yn)
yn+1 = c cos(a xn) + cos(b yn)

The one ring


a = 1.40, b = 1.56, c = 1.40, d = -6.56

Contribution by Robert Rodgers

Evaldraw script: attract.kc

Sample images