Farmer [5] gives plots of various Poincaré sections for the Mackey-Glass equation, a scalar DDE that exhibits chaotic behavior. Reproduce Fig. 2a of the paper by solving
y(t)
=
0.2  y(t-14)
1 + y(t-14)10
 -  0.1 y(t)
(4)
on [0,300] with history y(t) = 0.5 for t 0 and plotting y(t -14) against y(t). The figure begins with t = 50 to allow an initial transient time to settle down. To reproduce it, form an array of 1000 equally spaced points in [50,300], evaluate y(t) at these points, and then evaluate y(t-14).

[5]
J.D. Farmer, Chaotic attractors of an infinite-dimensional dynamical system, Physica D, 4 (1982) 366-393.