This is the two-dimensional map known as Martin's map: , .
Orbits are generated by iterating the map times using different initial points. The map parameters , , and can be varied manually or a random set can be launched. Three orbits are plotted initially, starting from three different initial points marked by locator objects "". You can drag these initial points or add and/or delete new ones (Alt+Click on Windows) inside the plot. Three orbit colors are used cyclically.
B. Martin, "Graphic Potential of Recursive Functions," J. Landsdown, R. A. Earnshaw, eds., Computers in Art, Design and Animation, New York: Springer–Verlag, 1989 pp. 109–129.